An Outbreak of Norovirus in a Long-term Care Facility — Guangzhou City, Guangdong Province, China, December 2024

An Outbreak of Norovirus in a Long-term Care Facility — Guangzhou City, Guangdong Province, China, December 2024 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article An Outbreak of Norovirus in a Long-term Care Facility — Guangzhou City, Guangdong Province, China, December 2024 Hui Wang, Yuanjing Xu, Huaping Xie, Yuanli Ling, Pengzhe Qin, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7296110/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Background This acute gastroenteritis outbreak represents the most extensive norovirus cluster reported in Guangzhou long-term care facilities in recent years. In order to control the outbreak, an epidemiological investigation was conducted to determine the causative agent, sources, role of transmission and risk factors of the infections while providing technical guidance to the institution for implementing infection control measures. Methods An epidemiological investigation was carried out for cases among elderly residents and staff members in the long-term care facility. A case-control study was conducted. Information on basic demographic characteristics, clinical presentations, exposure history, care giving interactions, off-site activities, participation in congregate events, kitchen staff health status, food hygiene, and drinking water hygiene was collected. Multivariate analysis was used to analyze risk factors. Rectal swabs of the cases and staff members, as well as environmental samples were collected to detect potential viruses and bacteria. Genotyping and environmental surveillance were implemented to delineate transmission pathways. Results The overall attack rate was 17.72% (126/711), including 554 elderly residents and 157 staff members. Key risk factors included requiring partial dressing assistance (adjusted odds ratio [ aOR ] = 1.92, 95% confidence interval [CI] : 1.06, 3.64), sharing dining tables with cases during meals ( aOR = 2.47, 95% CI : 1.54, 3.99), co-residing in dormitories with cases ( aOR = 2.58, 95% CI : 1.60, 4.17), off-site engagements during the pre-outbreak period (December 18–24) ( aOR = 86.03, 95% CI : 17.44, 2076.65). Genotype analysis confirmed norovirus GII.17[P17] in both caregivers and residents. Conclusions Our findings underscore the necessity of implementing infection control strategies, including early "Relative Static Management", rigorous enforcement of environmental disinfection and strict enforcement of caregivers compliance with personal protective equipment use in long-term care facilities. Health sciences/Diseases Health sciences/Health care Health sciences/Medical research Biological sciences/Microbiology Health sciences/Risk factors Figures Figure 1 Background Norovirus, a leading cause of acute gastroenteritis worldwide, poses a significant public health challenge, particularly in high-risk environments such as nursing homes and long-term care facilities(LTCF)[ 1 – 2 ]. In long-term care facilities, the closed environment, combined with the high density of residents and frequent person-to-person contact, creates conditions highly conducive to norovirus transmissions[ 3 – 5 ]. Transmission dynamics of the virus are complex, involving multiple routes, including the fecal-oral pathway, aerosolized vomitus particles, and environmental surface contamination. Previous studies indicate that the elderly experience the highest attack rates. Reports of such outbreaks occurring among this vulnerable population in community settings and long-term care facilities across China have become increasingly frequent in recent years[ 6 – 8 ]. Guangzhou, the capital city of Guangdong Province in southern China, has an elderly population exceeding two million people. On December 24, 2024, the Guangzhou Center for Disease Control and Prevention (Guangzhou CDC) was notified of an acute gastroenteritis occurring in a long-term care facility. The Guangzhou CDC immediately initiated an epidemiological investigation while providing technical guidance to the institution for implementing infection control measures. Methods Epidemiological investigation The 22-story long-term care facility accommodated 554 elderly residents and 157 staff members. Residential units occupied floors 5 through 20, with designated dining, rehabilitation, and recreational areas. Notably, staff dormitories were located on the 17th floor. The 21st floor functioned as a multipurpose activity space, while the 22nd floor comprised a rooftop garden and staff quarters reserved for kitchen personnel. Daily external visitors primarily consisted of family members and professional engagements. Family visitation operated on a scheduled appointment basis, with access confined to the ground-floor reception area during designated time blocks. Scheduled group activities were routinely conducted. Notably, a culturally significant “Winter Solstice Dumpling-Making” event took place on December 19, followed by a communal movie screening on December 20 within the 21st-floor multipurpose area. Case Definition and Identification During the outbreak period (December 18, 2024 - January 3, 2025), occupants (residents and staff) presenting with any of the following manifestations were identified as cases:1. Suspected case: ≥3 diarrhea episodes/24h with stool consistency changes (watery stool) OR ≥ 1 vomiting episodes/24h; 2. Laboratory-confirmed case: norovirus-positive anal swab/stool/vomitus specimen from suspected cases; 3. Clinical case: suspected cases epidemiologically linked to laboratory-confirmed cases; 4. Asymptomatic carrier: norovirus nucleic acid-positive individuals without compatible symptoms. To investigate the transmission mode, a case control study was conducted. This study enrolled all resident cases and uninfected resident controls selected from the same residential floors. Data on basic demographic characteristics, clinical presentations, exposure history (including care giving interactions, off-site activities, participation in congregate events), kitchen staff health status, food hygiene practices, and drinking water hygiene were collected. Data sources included absenteeism records, health surveillance registries, and structured interviews (conducted both in-person and via telephone). This study was approved by the Ethics Committee of Guangzhou center for disease control and prevention (GZCDC-ECHR-2023P0018) Specimen collection and laboratory tests Rectal swabs or stool specimens were collected from symptomatic and high-risk asymptomatic individuals, including residents, caregivers and kitchen staff. Environmental surface swabs were also collected from high-touch areas in the kitchen, common areas and resident rooms. Norovirus GI and GII were detected using a Norovirus GI/GII Real-Time RT-PCR Kit (Jiangsu Shuoshi Biotechnology, China) through real-time fluorescent RT-PCR performed on a 7500 Real-Time PCR System (Applied Biosystems, USA) with a Real-Time PCR Detection System (Bio-Rad, USA). Samples testing positive were subsequently amplified by RT-PCR using the OneStep RT-PCR Kit (Takara, Japan) with specific primers. The successfully amplified PCR products were then sequenced commercially by Guangzhou Tianyi Huiyuan Gene Technology Co., Ltd. (China). The resulting sequences were assembled using the SeqMan module in DNASTAR software (DNASTAR Inc., USA) and then submitted to the Norovirus Genotyping Tool for genotyping. Statistical analysis Descriptive statistics (frequencies and proportions) summarized symptom profiles. Attack rates were compared between residents and staff using Pearson’s chi-square or Fisher’s exact tests. Variables associated with infection in univariate analysis or deemed clinically relevant were included in a multivariable unconditional logistic regression model, using forward stepwise selection (Wald test). Significance was defined as P < 0.05 (two-tailed). Analyses utilized R software (v3.2.1; R Foundation for Statistical Computing). Results Descriptive epidemiology During the study period (December 18, 2024-January 3, 2025), comprehensive screening of 711 individuals (554 residents and 157 staff) revealed 126 laboratory-confirmed and clinically diagnosed infections, yielding an overall attack rate (AR) of 17.72% (126/711). Among residents, there were 26 cases laboratory-confirmed, while 62 met clinical diagnostic criteria. Staff infections included 1 clinically diagnosed caregivers and 37 asymptomatic carriers (34 caregivers and 3 kitchen personnel). Population distribution The resident population exhibited an AR of 15.88% (88/554), significantly lower than that among staff (24.20%,38/157; χ²=5.807, P = 0.016). Affected residents (n = 88) ranged from 60 to 99 years old (mean:83.2). No significant difference in AR was observed between male (15.25%, 27/177) and female residents (16.18%, 61/377; χ² = 0.077, P = 0.781). Time distribution The index case was an 84-year-old female with severe physical disabilities residing in Room 1505, who had been bedridden for an extended period. On December 21 at 8:00, she experienced vomiting in bed following breakfast, and was subsequently admitted to the hospital at 14:00 the same day. The patient reported no external food exposures during the 72-hour pre-onset period, except for consuming homemade meat broth provided by her daughter during the December 19 visitation. Case numbers exhibited surged during December 23–24 (epidemic peak: 24 cases/day), followed by sustained decline after intervention implementation. The last two documented cases occurred at 22:00 on January 1 (Fig. 1 ). Symptomatic residents manifested vomiting (73.86%), diarrhea (50.00%), and fever (7.95%), with three cases requiring hospitalization. Spatial distribution Resident cases were distributed across 12 floors, with the highest AR observed on the 15th floor (44.44%, 16/36 residents; P < 0.05) (Table 1 ). On-site residential staff demonstrated higher AR (25.64%, 30/117) compared to off-site staff (20.00%, 8/40), though this difference was not statistically significant (χ²=0.517, P = 0.472). Among caregivers across 12 working floors and kitchen staff, statistically significant variation in AR was observed with the highest AR of 100% (7/7) on the 15th floor(χ²=22.14, P < 0.05). Table 1 Norovirus Attack Rates Among Residents on Different Floors Floor Number of Cases Number of Residents AR(%) χ² P 15 16 36 44.44 40.42 < 0.001 20 15 40 37.5 13 10 36 27.78 9 9 38 23.68 14 8 38 21.05 6 8 38 21.05 19 6 32 18.75 8 5 38 13.16 18 4 38 10.53 16 3 38 7.89 11 2 38 5.26 5 2 38 5.26 Case-control study A case-control study involving all 88 resident cases and 360 uninfected controls from corresponding residential floors identified four significant transmission determinants. Multivariate analysis demonstrated elevated infection risks associated with requiring partial dressing assistance (adjusted odds ratio [ aOR ] = 1.92, 95% confidence interval [CI] : 1.06, 3.64), sharing dining tables with cases during meals ( aOR = 2.47, 95% CI : 1.54, 3.99), co-residing in dormitories with cases ( aOR = 2.58, 95% CI : 1.60, 4.17), off-site engagements during the pre-outbreak period (December 18–24) ( aOR = 86.03, 95% CI : 17.44, 2076.65) (Table 2 ). Table 2 Multivariable Analysis of Norovirus Infection Factors Variable Case group Control group Univariate Analysis Multivariate Analysis (n = 88) (n = 360) OR (95% CI ) P OR (95% CI ) P Gender Male 27(30.68) 122(33.89) 1 Female 61(69.32) 238(66.11) 1.15(0.70, 1.94) 0.57 Age 60–74 15(17.05) 66(18.33) 1 75–89 50(56.82) 220(61.11) 0.99(0.53, 1.94) 0.99 90~ 23(26.13) 74(20.56) 1.36(0.66, 2.89) 0.4 Disability Status Fully functional 3(3.41) 9(2.5) 1 Mildly disabled 16(18.18) 72(20) 0.65(0.17, 3.37) 0.69 Moderately disabled 31(35.23) 141(39.17) 0.64(0.18, 3.18) 0.47 Severely disabled 38(43.18) 138(38.33) 0.80(0.22, 3.95) 0.73 Feeding Method Self-feeding 71(80.68) 287(79.72) 1 Needs partial assistance 2(2.27) 10(2.78) 0.86(0.12, 3.41) 0.79 Fully dependent 15(17.05) 63(17.50) 0.97(0.50, 1.77) 0.9 Bath Independent 17(19.32) 82(22.78) 1 Needs assistance 71(80.68) 278(77.22) 1.22(0.69 ,2.26) 0.48 Dress 1.02(0.71, 1.48) 0.9 Fully independent 17(19.32) 94(26.11) 1 Needs partial assistance 48(54.55) 137(38.06) 1.92(1.06, 3.64) 0.03 Fully dependent 23(26.13) 129(35.83) 0.98(0.49, 1.98) 0.97 Toilet Fully independent 28(31.82) 132(36.67) 1 Needs partial assistance 19(21.59) 79(21.94) 1.14(0.59, 2.16) 0.7 Fully dependent 41(46.59) 149(41.39) 1.29(0.76, 2.23) 0.34 Walk Independent 19(21.59) 94(26.11) 1 Needs support or uses a cane 20(22.73) 96(26.67) 1.03(0.51, 2.07) 0.93 Only moves in a wheelchair 44(50) 152(42.22) 1.43(0.79, 2.64) 0.3 Fully dependent 5(5.68) 18(5) 1.39(0.41, 4.06) 0.56 Location of bed 1.49(0.86, 2.56) 0.15 Bed not adjacent to bathroom 50(56.82) 227(63.06) 1 Bed adjacent to bathroom 38(43.18) 133(36.94) 1.29(0.80, 2.08) 0.28 Sharing dining tables during meals with cases 1.96(1.14, 3.37) 0.01 No 39(44.32) 239(66.39) 1 Yes 49(55.68) 121(33.61) 2.47(1.54, 3.99) 0 Co-residing with cases 2.60(1.52, 4.45) 0 No 42(47.73) 253(70.28) 1 Yes 46(52.27) 107(29.72) 2.58(1.60, 4.17) 0 Off-site engagements (Dec.18–24) 114.01(14.33, 906.77) 0 No 69(78.41) 359(99.72) 1 Yes 19(21.59) 1(0.28) 86.03(17.44, 2076.65) 0 Winter Solstice Dumpling-Making( Dec.19) 0.51(0.16, 1.67) 0.27 No 81(92.05) 324(90) 1 Yes 7(7.95) 36(10) 0.79(0.31, 1.75) 0.56 Movie screening (Dec.20) No 79(89.77) 333(92.5) 1 Yes 9(10.23) 27(7.5) 1.42(0.60, 3.05) 0.4 Laboratory tests A total of 160 individuals’ rectal swab samples were tested for norovirus, inclusive of serial sampling. A total of 60 positive samples were detected, including 26 resident specimens (GII), 31 care worker specimens (GII), 3 kitchen staff specimens (GII). Environmental surveillance demonstrated 12.37% (12/97) surface contamination positivity, with 12 GII strains detected across high-contact surfaces including corridor handrails, door handles, public dryers, washing machines, air conditioning vents on the 15th floor, and dining surfaces on the 16th floor. Genotype analysis confirmed norovirus GII.17[P17][ 9 – 11 ] in both caregivers and residents, indicating staff-resident transmission chains. Environmental investigation The centralized kitchen facility in the basement maintained routine meal provision for all residents and staff through three daily food services. Meal distribution was conducted via dedicated trolleys assigned to specific floors, with caregivers responsible for delivering meals to designated dining areas or directly to bedridden residents in their rooms. Retrospective menu analysis for the 14-day pre-outbreak period identified no high-risk food items such as raw or cold dishes epidemiologically associated with gastroenteritis. All kitchen staff denied experiencing gastrointestinal symptoms during health screenings conducted prior to outbreak identification. Anal swab samples were collected from all kitchen staff on December 24, revealed one norovirus GII-positive case, with two additional kitchen delivery staff cases detected on December 31. The facility utilized a municipal water system with biannual microbial testing of filtered water dispensers, most recently conducted in August 2024. Residents received cooled boiled water provisions administered by caregivers. Caregivers residing primarily on the 4th floor shared a communal restroom lacking liquid soap dispensers. During high-exposure tasks including vomitus and excreta management, caregivers were not required to consistently utilize personal protective equipment (masks, gloves, or gowns) while rotating between assigned floors. Bed capacity limitations necessitated cohabitation of symptomatic and asymptomatic residents within shared rooms throughout the outbreak period. Public Health Response On December 26, the facility implemented four key provisions: 1)"Relative Static Management", which was enforced through zonal confinement, restricting resident/staff mobility to assigned floors and immediately cessation of non-essential congregate activities; 2)strict enforcement of caregivers compliance with personal protective equipment use of masks, gloves and gowns during exposure-prone tasks including vomitus/excreta management and contaminated linen handling; 3)implementation of standardized cleaning protocols, especially enhanced environmental disinfection protocols for high-contact surfaces; 4)installation of hand sanitizers in restrooms with enforced compliance. All cases recovered by January 4, 2025. No new cases emerged post-intervention, meeting outbreak closure criteria. Discussion Norovirus remains a predominant etiological agent of acute gastroenteritis outbreaks globally, particularly in congregate settings such as long-term care facilities where age-related immunological decline and functional dependencies amplify transmission risks[ 12 ]. To the best of our knowledge, this acute gastroenteritis outbreak represents the most extensive norovirus cluster reported in Guangzhou long-term care facilities in recent years. Integrated analysis of clinical manifestations, epidemiological patterns, and laboratory evidence excluded foodborne or waterborne transmission pathways, suggesting community-acquired introduction as the probable outbreak source. Four lines of evidence support this conclusion. First, the epidemic curve peaked at 24 cases/day precisely 72 hours post-Winter Solstice Festival (December 21). Second, case-control analysis demonstrated significant transmission risks associated with close interpersonal contact. Third, genotype analysis confirmed norovirus GII.17[P17] in both caregivers and residents. Fourth, rapid case declined followed implementation of "Relative Static Management" on December 26. While diarrhea predominates in norovirus-infected adults according to existing literature[ 13 ], this outbreak demonstrated vomiting as the principal clinical manifestation (73.86% of cases) [ 14 ]. This phenotype divergence may correlate with the GII.17 strain, which has a higher standardized vomiting proportion compared to other strains [ 15 ]. Transmission dynamics were amplified by two facility-specific factors: 1)a high proportion of residents with physical/cognitive impairments compromising vomitus containment capacity, and 2) inconsistent adherence to personal protective equipment (masks/gloves/gowns) during care giving, compounded by absent hand hygiene[ 16 – 17 ] provisions in staff restrooms and inadequate environmental decontamination protocols. Environmental surveillance confirmed widespread contamination (12.37% surface positivity), including norovirus detection in 15th-floor air conditioning vents, suggesting potential aerosol-mediated dispersion[ 18 ]. These findings emphasize the necessity of integrated infection control strategies combining ventilation optimization, surface disinfection, and standardized vomitus management protocols to mitigate transmission risks in long-term care facilities[ 19 ]. This investigation revealed elevated norovirus infection risks among residents requiring partial dressing assistance compared to fully independent or completely dependent individuals. This finding likely reflects increased duration and proximity of contact with caregivers during winter care routines. For partially dependent residents, dressing procedures involving attempted cooperation while maintaining unstable postures prolong individual care sessions, leading to extended close-contact exposure and enhanced opportunities for person-to-person transmission. These observations align with Nathalie Nicolay's findings demonstrating highly dependent elderly residents had higher risk of norovirus infection than those with lower dependency levels. Specifically, residents with cognitive impairments requiring frequent close-contact care, such as Alzheimer's disease patients, exhibited heightened susceptibility[ 20 ]. Infection risks associated with shared dining tables and dormitory cohabitation identifying contact transmission as the primary norovirus dissemination route in congregate settings[ 21 ]. These findings underscore the critical need for tailored infection control measures addressing dependency-specific care interactions in long-term care facilities. The extreme aOR for off-site engagements ( aOR = 86.03, 95% CI : 17.44, 2076.65) may reflect limited control sampling. However, it underscores community exposure as a key outbreak driver. Conclusion This epidemiological investigation elucidates key transmission dynamics of norovirus in congregate elderly long-term care facilities, highlighting elevated risks associated with high-density residential environments. The findings substantiate three essential control measures for institutional norovirus outbreaks, including early "Relative Static Management", rigorous enforcement of environmental disinfection and strict enforcement of caregivers compliance with personal protective equipment use. Abbreviations LTCF Long-term care facilities aOR Adjusted odds ratio CI Confidence interval AR Attack rate Declarations Ethics approval and consent to participate The study was reviewed and approved by the Ethics Committee of Guangzhou Center for Disease Control and Prevention（GZCDC-ECHER-2023P0018）. This study complies with the Declaration of Helsinki. Informed consent was obtained from subjects’ legal guardians for specimen collection during the norovirus outbreak containment. Consent for publication Not applicable. Availability of data and material The data that support the findings of this study are available from the National Public Health Emergency Event Surveillance System (PHEESS) but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of PHEESS. Competing interests The authors declare that they have no competing interests. Funding Supported by the Science and Technology Program of Guangzhou（2024A03J0368） and the Medical Research Fund Project of Guangdong（A2024640）. Authors' contributions Design and conception: Hui Wang; Yuanjing Xu; Data assessment:Pengzhe Qin; Lei Luo； Statistical analysis:Hui Wang; Yuanjing Xu; Writing of the manuscript: Hui Wang; Yuanjing Xu; Editing and final approval of the manuscript: Hui Wang; Yuanjing Xu; Huaping Xie; Yuanli Ling; Pengzhe Qin; Lei Luo Acknowledgments We thank all the participants in the study. References Ahmed, S. M. et al. Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis. Lancet Infect. Dis. 14 (8), 725–730 (2014). Martín Bazarra, P. et al. Norovirus GII.17 gastroenteritis outbreak in a nursing home (Enferm Infecc Microbiol Clin (Engl Ed, 2025). Sugimoto, K. et al. Infection control measures promoted by the public health center for housing for the elderly facilities during norovirus cluster outbreaks. J. Rural Med. 17 (3), 151–157 (2022). Teesing, G. R. et al. Improving Hand Hygiene Compliance in Nursing Homes: Protocol for a Cluster Randomized Controlled Trial (HANDSOME Study). JMIR Res. Protoc. 9 (5), e17419 (2020). Martín Bazarra, P. et al. Norovirus GII.17 gastroenteritis outbreak in a nursing home (Enferm Infecc Microbiol Clin (Engl Ed, 2025). Zheng, Q. M. et al. Epidemiological investigation of a norovirus GII.4 Sydney outbreak in a China elder care facility. Jpn J. Infect. Dis. 68 , 70–74 (2015). Lin, H. et al. Institutional risk factors for norovirus outbreaks in Hong Kong elderly homes: A retrospective cohort study. BMC Public. Health . 11 , 297 (2011). Fankhauser, R. L. et al. Epidemiologic and molecular trends of Norwalk-like viruses associated with outbreaks of gastroenteritis in the United States. Jinfectdis 186 (1), 1 (2002). Chan, M. C. et al. Rapid emergence and predominance of a broadly recognizing and fast-evolving norovirus GII.17 variant in late 2014. Nat. Commun. 6 , 10061 (2015). Fu, J. et al. Emergence of a new GII.17 norovirus variant in patients with acute gastroenteritis in Jiangsu, China, September 2014 to March 2015 EUROSURVEILLANCE. ; 20 (24): (2015). Jin, M. et al. Characterization of the new GII.17 norovirus variant that emerged recently as the predominant strain in China. J. Gen. Virol. 97 (10), 2620–2632 (2016). Sugimoto, K., Sato, N., Amamiya, Y. & Hosoya, N. Infection control measures promoted by the public health center for housing for the elderly facilities during norovirus cluster outbreaks. J. Rural Med. 17 (3), 151–157 (2022). Götz, H. et al. Clinical spectrum and transmission characteristics of infection with Norwalk-like virus: findings from a large community outbreak in Sweden. Clin. Infect. Dis. 33 (5), 622–628 (2001). Li, J. S., Deng, A. P., Mo, Y. L., Li, H. & Sun, L. M. A Norovirus caused gastroenteritis outbreak in a nursing home in Guangdong. Disease Surveillance . 30 (3), 242–244 (2015). (In Chinese). Zhang, M. et al. Epidemiological characteristics of outbreaks of norovirus-GⅡ.2, GⅡ.17 and GⅡ.4/Sydney in Guangdong province, 2013–2017. Chin. J. Epidemiol. 39 (9), 1210–1215 (2018). (In Chinese). Teesing, G. R. et al. Association of environmental surface contamination with hand hygiene and infections in nursing homes: a prospective cohort study. Infect. Prev. Pract. 3 (2), 100129 (2021). Assab, R. & Temime, L. The role of hand hygiene in controlling norovirus spread in nursing homes. BMC Infect. Dis. 16 , 395 (2016). Tan, M., Tian, Y., Zhang, D., Wang, Q. & Gao, Z. Aerosol Transmission of Norovirus. Viruses-Basel 16 (1), 151 (2024). Adams, C. et al. Quantifying the roles of vomiting, diarrhea, and residents vs. staff in norovirus transmission in U.S. nursing home outbreaks. Plos Comput. Biol. 16 (3), e1007271 (2020). Nicolay, N. et al. The role of dependency in a norovirus outbreak in a nursing home. Eur. Geriatr. Med. 9 (6), 837–844 (2018). Li, J., Pan, H., Xiao, W., Hu, J. & Yuan, Z. Epidemiology of confirmed and suspected norovirus outbreaks in Shanghai, 2010–2014. Chin. J. Epidemiol. 36 (11), 1249–1252 (2015). (In Chinese). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 17 Dec, 2025 Editor assigned by journal 09 Dec, 2025 Editor invited by journal 22 Oct, 2025 Submission checks completed at journal 20 Oct, 2025 First submitted to journal 14 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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12:30:25","extension":"html","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":92467,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7296110/v1/15e5b3d7b10d173456e0627a.html"},{"id":98778875,"identity":"73d821c1-8e85-4cb4-92cf-18d395a21955","added_by":"auto","created_at":"2025-12-22 12:29:46","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":28914,"visible":true,"origin":"","legend":"\u003cp\u003eEpidemic Curve of Norovirus Infection Outbreak Cases in the Long-term Care Facility\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7296110/v1/7831851c1f3462d4eb48a399.png"},{"id":98783439,"identity":"6ed7f5ce-299e-47eb-bdcd-ae6ad976e971","added_by":"auto","created_at":"2025-12-22 12:41:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1086851,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7296110/v1/f374f51a-f42d-402f-82be-fbc0b4f2e688.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"An Outbreak of Norovirus in a Long-term Care Facility — Guangzhou City, Guangdong Province, China, December 2024","fulltext":[{"header":"Background","content":"\u003cp\u003eNorovirus, a leading cause of acute gastroenteritis worldwide, poses a significant public health challenge, particularly in high-risk environments such as nursing homes and long-term care facilities(LTCF)[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In long-term care facilities, the closed environment, combined with the high density of residents and frequent person-to-person contact, creates conditions highly conducive to norovirus transmissions[\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Transmission dynamics of the virus are complex, involving multiple routes, including the fecal-oral pathway, aerosolized vomitus particles, and environmental surface contamination. Previous studies indicate that the elderly experience the highest attack rates. Reports of such outbreaks occurring among this vulnerable population in community settings and long-term care facilities across China have become increasingly frequent in recent years[\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Guangzhou, the capital city of Guangdong Province in southern China, has an elderly population exceeding two million people.\u003c/p\u003e \u003cp\u003eOn December 24, 2024, the Guangzhou Center for Disease Control and Prevention (Guangzhou CDC) was notified of an acute gastroenteritis occurring in a long-term care facility. The Guangzhou CDC immediately initiated an epidemiological investigation while providing technical guidance to the institution for implementing infection control measures.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eEpidemiological investigation\u003c/h2\u003e \u003cp\u003eThe 22-story long-term care facility accommodated 554 elderly residents and 157 staff members. Residential units occupied floors 5 through 20, with designated dining, rehabilitation, and recreational areas. Notably, staff dormitories were located on the 17th floor. The 21st floor functioned as a multipurpose activity space, while the 22nd floor comprised a rooftop garden and staff quarters reserved for kitchen personnel. Daily external visitors primarily consisted of family members and professional engagements. Family visitation operated on a scheduled appointment basis, with access confined to the ground-floor reception area during designated time blocks. Scheduled group activities were routinely conducted. Notably, a culturally significant \u0026ldquo;Winter Solstice Dumpling-Making\u0026rdquo; event took place on December 19, followed by a communal movie screening on December 20 within the 21st-floor multipurpose area.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eCase Definition and Identification\u003c/h3\u003e\n\u003cp\u003eDuring the outbreak period (December 18, 2024 - January 3, 2025), occupants (residents and staff) presenting with any of the following manifestations were identified as cases:1. Suspected case: \u0026ge;3 diarrhea episodes/24h with stool consistency changes (watery stool) OR\u0026thinsp;\u0026ge;\u0026thinsp;1 vomiting episodes/24h; 2. Laboratory-confirmed case: norovirus-positive anal swab/stool/vomitus specimen from suspected cases; 3. Clinical case: suspected cases epidemiologically linked to laboratory-confirmed cases; 4. Asymptomatic carrier: norovirus nucleic acid-positive individuals without compatible symptoms.\u003c/p\u003e \u003cp\u003eTo investigate the transmission mode, a case control study was conducted. This study enrolled all resident cases and uninfected resident controls selected from the same residential floors. Data on basic demographic characteristics, clinical presentations, exposure history (including care giving interactions, off-site activities, participation in congregate events), kitchen staff health status, food hygiene practices, and drinking water hygiene were collected. Data sources included absenteeism records, health surveillance registries, and structured interviews (conducted both in-person and via telephone). This study was approved by the Ethics Committee of Guangzhou center for disease control and prevention (GZCDC-ECHR-2023P0018)\u003c/p\u003e\n\u003ch3\u003eSpecimen collection and laboratory tests\u003c/h3\u003e\n\u003cp\u003eRectal swabs or stool specimens were collected from symptomatic and high-risk asymptomatic individuals, including residents, caregivers and kitchen staff. Environmental surface swabs were also collected from high-touch areas in the kitchen, common areas and resident rooms. Norovirus GI and GII were detected using a Norovirus GI/GII Real-Time RT-PCR Kit (Jiangsu Shuoshi Biotechnology, China) through real-time fluorescent RT-PCR performed on a 7500 Real-Time PCR System (Applied Biosystems, USA) with a Real-Time PCR Detection System (Bio-Rad, USA). Samples testing positive were subsequently amplified by RT-PCR using the OneStep RT-PCR Kit (Takara, Japan) with specific primers. The successfully amplified PCR products were then sequenced commercially by Guangzhou Tianyi Huiyuan Gene Technology Co., Ltd. (China). The resulting sequences were assembled using the SeqMan module in DNASTAR software (DNASTAR Inc., USA) and then submitted to the Norovirus Genotyping Tool for genotyping.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eDescriptive statistics (frequencies and proportions) summarized symptom profiles. Attack rates were compared between residents and staff using Pearson\u0026rsquo;s chi-square or Fisher\u0026rsquo;s exact tests. Variables associated with infection in univariate analysis or deemed clinically relevant were included in a multivariable unconditional logistic regression model, using forward stepwise selection (Wald test). Significance was defined as \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 (two-tailed). Analyses utilized R software (v3.2.1; R Foundation for Statistical Computing).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eDescriptive epidemiology\u003c/h2\u003e \u003cp\u003eDuring the study period (December 18, 2024-January 3, 2025), comprehensive screening of 711 individuals (554 residents and 157 staff) revealed 126 laboratory-confirmed and clinically diagnosed infections, yielding an overall attack rate (AR) of 17.72% (126/711). Among residents, there were 26 cases laboratory-confirmed, while 62 met clinical diagnostic criteria. Staff infections included 1 clinically diagnosed caregivers and 37 asymptomatic carriers (34 caregivers and 3 kitchen personnel).\u003c/p\u003e \u003cp\u003ePopulation distribution\u003c/p\u003e \u003cp\u003eThe resident population exhibited an AR of 15.88% (88/554), significantly lower than that among staff (24.20%,38/157; χ\u0026sup2;=5.807, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.016). Affected residents (n\u0026thinsp;=\u0026thinsp;88) ranged from 60 to 99 years old (mean:83.2). No significant difference in AR was observed between male (15.25%, 27/177) and female residents (16.18%, 61/377; χ\u0026sup2; = 0.077, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.781).\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eTime distribution\u003c/h3\u003e\n\u003cp\u003eThe index case was an 84-year-old female with severe physical disabilities residing in Room 1505, who had been bedridden for an extended period. On December 21 at 8:00, she experienced vomiting in bed following breakfast, and was subsequently admitted to the hospital at 14:00 the same day. The patient reported no external food exposures during the 72-hour pre-onset period, except for consuming homemade meat broth provided by her daughter during the December 19 visitation. Case numbers exhibited surged during December 23\u0026ndash;24 (epidemic peak: 24 cases/day), followed by sustained decline after intervention implementation. The last two documented cases occurred at 22:00 on January 1 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Symptomatic residents manifested vomiting (73.86%), diarrhea (50.00%), and fever (7.95%), with three cases requiring hospitalization.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eSpatial distribution\u003c/p\u003e \u003cp\u003eResident cases were distributed across 12 floors, with the highest AR observed on the 15th floor (44.44%, 16/36 residents; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). On-site residential staff demonstrated higher AR (25.64%, 30/117) compared to off-site staff (20.00%, 8/40), though this difference was not statistically significant (χ\u0026sup2;=0.517, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.472). Among caregivers across 12 working floors and kitchen staff, statistically significant variation in AR was observed with the highest AR of 100% (7/7) on the 15th floor(χ\u0026sup2;=22.14, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eNorovirus Attack Rates Among Residents on Different Floors\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFloor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of Cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNumber of Residents\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAR(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eχ\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e 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\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e18.75\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.89\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eCase-control study\u003c/p\u003e \u003cp\u003eA case-control study involving all 88 resident cases and 360 uninfected controls from corresponding residential floors identified four significant transmission determinants. Multivariate analysis demonstrated elevated infection risks associated with requiring partial dressing assistance (adjusted odds ratio [\u003cem\u003eaOR\u003c/em\u003e]\u0026thinsp;=\u0026thinsp;1.92, 95% confidence interval \u003cem\u003e[CI]\u003c/em\u003e: 1.06, 3.64), sharing dining tables with cases during meals (\u003cem\u003eaOR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.47, 95% \u003cem\u003eCI\u003c/em\u003e: 1.54, 3.99), co-residing in dormitories with cases (\u003cem\u003eaOR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.58, 95% \u003cem\u003eCI\u003c/em\u003e: 1.60, 4.17), off-site engagements during the pre-outbreak period (December 18\u0026ndash;24) (\u003cem\u003eaOR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;86.03, 95%\u003cem\u003eCI\u003c/em\u003e: 17.44, 2076.65) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariable Analysis of Norovirus Infection Factors\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCase group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControl group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eUnivariate Analysis\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eMultivariate Analysis\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;88)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;360)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eOR\u003c/em\u003e(95%\u003cem\u003eCI\u003c/em\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eOR\u003c/em\u003e(95%\u003cem\u003eCI\u003c/em\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27(30.68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e122(33.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61(69.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e238(66.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.15(0.70, 1.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e60\u0026ndash;74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15(17.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66(18.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e75\u0026ndash;89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50(56.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e220(61.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.99(0.53, 1.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e90~\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23(26.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e74(20.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.36(0.66, 2.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDisability Status\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFully functional\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3(3.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9(2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMildly disabled\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16(18.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72(20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.65(0.17, 3.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModerately disabled\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31(35.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e141(39.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.64(0.18, 3.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSeverely disabled\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38(43.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e138(38.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.80(0.22, 3.95)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFeeding Method\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSelf-feeding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e71(80.68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e287(79.72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeeds partial assistance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2(2.27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10(2.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.86(0.12, 3.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFully dependent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15(17.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e63(17.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.97(0.50, 1.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBath\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndependent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17(19.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e82(22.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeeds assistance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e71(80.68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e278(77.22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.22(0.69 ,2.26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDress\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.02(0.71, 1.48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFully independent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17(19.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e94(26.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeeds partial assistance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48(54.55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e137(38.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.92(1.06, 3.64)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFully dependent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23(26.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e129(35.83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.98(0.49, 1.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eToilet\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFully independent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28(31.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e132(36.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeeds partial assistance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19(21.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79(21.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.14(0.59, 2.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFully dependent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e41(46.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e149(41.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.29(0.76, 2.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWalk\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndependent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19(21.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e94(26.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeeds support or uses a cane\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20(22.73)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e96(26.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.03(0.51, 2.07)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOnly moves in a wheelchair\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44(50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e152(42.22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.43(0.79, 2.64)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFully dependent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5(5.68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18(5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.39(0.41, 4.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLocation of bed\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.49(0.86, 2.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBed not adjacent to bathroom\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50(56.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e227(63.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBed adjacent to bathroom\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38(43.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e133(36.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.29(0.80, 2.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSharing dining tables during meals with cases\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.96(1.14, 3.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e39(44.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e239(66.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49(55.68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e121(33.61)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.47(1.54, 3.99)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCo-residing with cases\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.60(1.52, 4.45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42(47.73)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e253(70.28)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46(52.27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e107(29.72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.58(1.60, 4.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOff-site engagements (Dec.18\u0026ndash;24)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e114.01(14.33, 906.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e69(78.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e359(99.72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19(21.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(0.28)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e86.03(17.44, 2076.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWinter Solstice Dumpling-Making( Dec.19)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.51(0.16, 1.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81(92.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e324(90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7(7.95)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36(10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.79(0.31, 1.75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMovie screening (Dec.20)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e79(89.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e333(92.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9(10.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27(7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.42(0.60, 3.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eLaboratory tests\u003c/h3\u003e\n\u003cp\u003eA total of 160 individuals\u0026rsquo; rectal swab samples were tested for norovirus, inclusive of serial sampling. A total of 60 positive samples were detected, including 26 resident specimens (GII), 31 care worker specimens (GII), 3 kitchen staff specimens (GII). Environmental surveillance demonstrated 12.37% (12/97) surface contamination positivity, with 12 GII strains detected across high-contact surfaces including corridor handrails, door handles, public dryers, washing machines, air conditioning vents on the 15th floor, and dining surfaces on the 16th floor. Genotype analysis confirmed norovirus GII.17[P17][\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] in both caregivers and residents, indicating staff-resident transmission chains.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eEnvironmental investigation\u003c/h2\u003e \u003cp\u003eThe centralized kitchen facility in the basement maintained routine meal provision for all residents and staff through three daily food services. Meal distribution was conducted via dedicated trolleys assigned to specific floors, with caregivers responsible for delivering meals to designated dining areas or directly to bedridden residents in their rooms. Retrospective menu analysis for the 14-day pre-outbreak period identified no high-risk food items such as raw or cold dishes epidemiologically associated with gastroenteritis. All kitchen staff denied experiencing gastrointestinal symptoms during health screenings conducted prior to outbreak identification. Anal swab samples were collected from all kitchen staff on December 24, revealed one norovirus GII-positive case, with two additional kitchen delivery staff cases detected on December 31.\u003c/p\u003e \u003cp\u003eThe facility utilized a municipal water system with biannual microbial testing of filtered water dispensers, most recently conducted in August 2024. Residents received cooled boiled water provisions administered by caregivers.\u003c/p\u003e \u003cp\u003eCaregivers residing primarily on the 4th floor shared a communal restroom lacking liquid soap dispensers. During high-exposure tasks including vomitus and excreta management, caregivers were not required to consistently utilize personal protective equipment (masks, gloves, or gowns) while rotating between assigned floors. Bed capacity limitations necessitated cohabitation of symptomatic and asymptomatic residents within shared rooms throughout the outbreak period.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003ePublic Health Response\u003c/h2\u003e \u003cp\u003eOn December 26, the facility implemented four key provisions: 1)\"Relative Static Management\", which was enforced through zonal confinement, restricting resident/staff mobility to assigned floors and immediately cessation of non-essential congregate activities; 2)strict enforcement of caregivers compliance with personal protective equipment use of masks, gloves and gowns during exposure-prone tasks including vomitus/excreta management and contaminated linen handling; 3)implementation of standardized cleaning protocols, especially enhanced environmental disinfection protocols for high-contact surfaces; 4)installation of hand sanitizers in restrooms with enforced compliance. All cases recovered by January 4, 2025. No new cases emerged post-intervention, meeting outbreak closure criteria.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eNorovirus remains a predominant etiological agent of acute gastroenteritis outbreaks globally, particularly in congregate settings such as long-term care facilities where age-related immunological decline and functional dependencies amplify transmission risks[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. To the best of our knowledge, this acute gastroenteritis outbreak represents the most extensive norovirus cluster reported in Guangzhou long-term care facilities in recent years. Integrated analysis of clinical manifestations, epidemiological patterns, and laboratory evidence excluded foodborne or waterborne transmission pathways, suggesting community-acquired introduction as the probable outbreak source. Four lines of evidence support this conclusion. First, the epidemic curve peaked at 24 cases/day precisely 72 hours post-Winter Solstice Festival (December 21). Second, case-control analysis demonstrated significant transmission risks associated with close interpersonal contact. Third, genotype analysis confirmed norovirus GII.17[P17] in both caregivers and residents. Fourth, rapid case declined followed implementation of \"Relative Static Management\" on December 26.\u003c/p\u003e \u003cp\u003eWhile diarrhea predominates in norovirus-infected adults according to existing literature[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], this outbreak demonstrated vomiting as the principal clinical manifestation (73.86% of cases) [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. This phenotype divergence may correlate with the GII.17 strain, which has a higher standardized vomiting proportion compared to other strains [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Transmission dynamics were amplified by two facility-specific factors: 1)a high proportion of residents with physical/cognitive impairments compromising vomitus containment capacity, and 2) inconsistent adherence to personal protective equipment (masks/gloves/gowns) during care giving, compounded by absent hand hygiene[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] provisions in staff restrooms and inadequate environmental decontamination protocols. Environmental surveillance confirmed widespread contamination (12.37% surface positivity), including norovirus detection in 15th-floor air conditioning vents, suggesting potential aerosol-mediated dispersion[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. These findings emphasize the necessity of integrated infection control strategies combining ventilation optimization, surface disinfection, and standardized vomitus management protocols to mitigate transmission risks in long-term care facilities[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. This investigation revealed elevated norovirus infection risks among residents requiring partial dressing assistance compared to fully independent or completely dependent individuals. This finding likely reflects increased duration and proximity of contact with caregivers during winter care routines. For partially dependent residents, dressing procedures involving attempted cooperation while maintaining unstable postures prolong individual care sessions, leading to extended close-contact exposure and enhanced opportunities for person-to-person transmission. These observations align with Nathalie Nicolay's findings demonstrating highly dependent elderly residents had higher risk of norovirus infection than those with lower dependency levels. Specifically, residents with cognitive impairments requiring frequent close-contact care, such as Alzheimer's disease patients, exhibited heightened susceptibility[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Infection risks associated with shared dining tables and dormitory cohabitation identifying contact transmission as the primary norovirus dissemination route in congregate settings[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. These findings underscore the critical need for tailored infection control measures addressing dependency-specific care interactions in long-term care facilities. The extreme \u003cem\u003eaOR\u003c/em\u003e for off-site engagements (\u003cem\u003eaOR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;86.03, 95%\u003cem\u003eCI\u003c/em\u003e: 17.44, 2076.65) may reflect limited control sampling. However, it underscores community exposure as a key outbreak driver.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis epidemiological investigation elucidates key transmission dynamics of norovirus in congregate elderly long-term care facilities, highlighting elevated risks associated with high-density residential environments. The findings substantiate three essential control measures for institutional norovirus outbreaks, including early \"Relative Static Management\", rigorous enforcement of environmental disinfection and strict enforcement of caregivers compliance with personal protective equipment use.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eLTCF \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Long-term care facilities\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eaOR\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u003c/em\u003eAdjusted odds ratio\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCI \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Confidence interval\u003c/p\u003e\n\u003cp\u003eAR \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Attack rate \u003cem\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/em\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was reviewed and approved by the Ethics Committee of Guangzhou Center for Disease Control and Prevention（GZCDC-ECHER-2023P0018）. This study complies with the Declaration of Helsinki. Informed consent was obtained from subjects\u0026rsquo; legal guardians for specimen collection during the norovirus outbreak containment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available from the National Public Health Emergency Event Surveillance System (PHEESS) but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of PHEESS.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSupported by the Science and Technology Program of Guangzhou（2024A03J0368）\u0026nbsp;and the Medical Research Fund Project of Guangdong（A2024640）.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDesign and conception: Hui Wang; Yuanjing Xu;\u003c/p\u003e\n\u003cp\u003eData assessment:Pengzhe Qin; Lei Luo；\u003c/p\u003e\n\u003cp\u003eStatistical analysis:Hui Wang; Yuanjing Xu;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWriting of the manuscript: Hui Wang; Yuanjing Xu;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEditing and final approval of the manuscript: Hui Wang; Yuanjing Xu; Huaping Xie; Yuanli Ling; Pengzhe Qin; Lei Luo\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank all the participants in the study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAhmed, S. M. et al. Global prevalence of norovirus in cases of gastroenteritis: a systematic review and meta-analysis. \u003cem\u003eLancet Infect. Dis.\u003c/em\u003e \u003cb\u003e14\u003c/b\u003e (8), 725\u0026ndash;730 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMart\u0026iacute;n Bazarra, P. et al. \u003cem\u003eNorovirus GII.17 gastroenteritis outbreak in a nursing home\u003c/em\u003e (Enferm Infecc Microbiol Clin (Engl Ed, 2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSugimoto, K. et al. Infection control measures promoted by the public health center for housing for the elderly facilities during norovirus cluster outbreaks. \u003cem\u003eJ. Rural Med.\u003c/em\u003e \u003cb\u003e17\u003c/b\u003e (3), 151\u0026ndash;157 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeesing, G. R. et al. Improving Hand Hygiene Compliance in Nursing Homes: Protocol for a Cluster Randomized Controlled Trial (HANDSOME Study). \u003cem\u003eJMIR Res. Protoc.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e (5), e17419 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMart\u0026iacute;n Bazarra, P. et al. \u003cem\u003eNorovirus GII.17 gastroenteritis outbreak in a nursing home\u003c/em\u003e (Enferm Infecc Microbiol Clin (Engl Ed, 2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZheng, Q. M. et al. Epidemiological investigation of a norovirus GII.4 Sydney outbreak in a China elder care facility. \u003cem\u003eJpn J. Infect. Dis.\u003c/em\u003e \u003cb\u003e68\u003c/b\u003e, 70\u0026ndash;74 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLin, H. et al. Institutional risk factors for norovirus outbreaks in Hong Kong elderly homes: A retrospective cohort study. \u003cem\u003eBMC Public. Health\u003c/em\u003e. \u003cb\u003e11\u003c/b\u003e, 297 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFankhauser, R. L. et al. Epidemiologic and molecular trends of Norwalk-like viruses associated with outbreaks of gastroenteritis in the United States. \u003cem\u003eJinfectdis\u003c/em\u003e \u003cb\u003e186\u003c/b\u003e (1), 1 (2002).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChan, M. C. et al. Rapid emergence and predominance of a broadly recognizing and fast-evolving norovirus GII.17 variant in late 2014. \u003cem\u003eNat. Commun.\u003c/em\u003e \u003cb\u003e6\u003c/b\u003e, 10061 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFu, J. et al. Emergence of a new GII.17 norovirus variant in patients with acute gastroenteritis in Jiangsu, China, September 2014 to March 2015 EUROSURVEILLANCE. ; 20 (24): (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJin, M. et al. Characterization of the new GII.17 norovirus variant that emerged recently as the predominant strain in China. \u003cem\u003eJ. Gen. Virol.\u003c/em\u003e \u003cb\u003e97\u003c/b\u003e (10), 2620\u0026ndash;2632 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSugimoto, K., Sato, N., Amamiya, Y. \u0026amp; Hosoya, N. Infection control measures promoted by the public health center for housing for the elderly facilities during norovirus cluster outbreaks. \u003cem\u003eJ. Rural Med.\u003c/em\u003e \u003cb\u003e17\u003c/b\u003e (3), 151\u0026ndash;157 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG\u0026ouml;tz, H. et al. Clinical spectrum and transmission characteristics of infection with Norwalk-like virus: findings from a large community outbreak in Sweden. \u003cem\u003eClin. Infect. Dis.\u003c/em\u003e \u003cb\u003e33\u003c/b\u003e (5), 622\u0026ndash;628 (2001).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, J. S., Deng, A. P., Mo, Y. L., Li, H. \u0026amp; Sun, L. M. A Norovirus caused gastroenteritis outbreak in a nursing home in Guangdong. \u003cem\u003eDisease Surveillance\u003c/em\u003e. \u003cb\u003e30\u003c/b\u003e (3), 242\u0026ndash;244 (2015). (In Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, M. et al. Epidemiological characteristics of outbreaks of norovirus-GⅡ.2, GⅡ.17 and GⅡ.4/Sydney in Guangdong province, 2013\u0026ndash;2017. \u003cem\u003eChin. J. Epidemiol.\u003c/em\u003e \u003cb\u003e39\u003c/b\u003e (9), 1210\u0026ndash;1215 (2018). (In Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeesing, G. R. et al. Association of environmental surface contamination with hand hygiene and infections in nursing homes: a prospective cohort study. \u003cem\u003eInfect. Prev. Pract.\u003c/em\u003e \u003cb\u003e3\u003c/b\u003e (2), 100129 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAssab, R. \u0026amp; Temime, L. The role of hand hygiene in controlling norovirus spread in nursing homes. \u003cem\u003eBMC Infect. Dis.\u003c/em\u003e \u003cb\u003e16\u003c/b\u003e, 395 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTan, M., Tian, Y., Zhang, D., Wang, Q. \u0026amp; Gao, Z. Aerosol Transmission of Norovirus. \u003cem\u003eViruses-Basel\u003c/em\u003e \u003cb\u003e16\u003c/b\u003e (1), 151 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAdams, C. et al. Quantifying the roles of vomiting, diarrhea, and residents vs. staff in norovirus transmission in U.S. nursing home outbreaks. \u003cem\u003ePlos Comput. Biol.\u003c/em\u003e \u003cb\u003e16\u003c/b\u003e (3), e1007271 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNicolay, N. et al. The role of dependency in a norovirus outbreak in a nursing home. \u003cem\u003eEur. Geriatr. Med.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e (6), 837\u0026ndash;844 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, J., Pan, H., Xiao, W., Hu, J. \u0026amp; Yuan, Z. Epidemiology of confirmed and suspected norovirus outbreaks in Shanghai, 2010\u0026ndash;2014. \u003cem\u003eChin. J. Epidemiol.\u003c/em\u003e \u003cb\u003e36\u003c/b\u003e (11), 1249\u0026ndash;1252 (2015). (In Chinese).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7296110/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7296110/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThis acute gastroenteritis outbreak represents the most extensive norovirus cluster reported in Guangzhou long-term care facilities in recent years. In order to control the outbreak, an epidemiological investigation was conducted to determine the causative agent, sources, role of transmission and risk factors of the infections while providing technical guidance to the institution for implementing infection control measures.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eAn epidemiological investigation was carried out for cases among elderly residents and staff members in the long-term care facility. A case-control study was conducted. Information on basic demographic characteristics, clinical presentations, exposure history, care giving interactions, off-site activities, participation in congregate events, kitchen staff health status, food hygiene, and drinking water hygiene was collected. Multivariate analysis was used to analyze risk factors. Rectal swabs of the cases and staff members, as well as environmental samples were collected to detect potential viruses and bacteria. Genotyping and environmental surveillance were implemented to delineate transmission pathways.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe overall attack rate was 17.72% (126/711), including 554 elderly residents and 157 staff members. Key risk factors included requiring partial dressing assistance (adjusted odds ratio [\u003cem\u003eaOR\u003c/em\u003e]\u0026thinsp;=\u0026thinsp;1.92, 95% confidence interval \u003cem\u003e[CI]\u003c/em\u003e: 1.06, 3.64), sharing dining tables with cases during meals (\u003cem\u003eaOR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.47, 95% \u003cem\u003eCI\u003c/em\u003e: 1.54, 3.99), co-residing in dormitories with cases (\u003cem\u003eaOR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.58, 95% \u003cem\u003eCI\u003c/em\u003e: 1.60, 4.17), off-site engagements during the pre-outbreak period (December 18\u0026ndash;24) (\u003cem\u003eaOR\u003c/em\u003e\u0026thinsp;=\u0026thinsp;86.03, 95%\u003cem\u003eCI\u003c/em\u003e: 17.44, 2076.65). Genotype analysis confirmed norovirus GII.17[P17] in both caregivers and residents.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eOur findings underscore the necessity of implementing infection control strategies, including early \"Relative Static Management\", rigorous enforcement of environmental disinfection and strict enforcement of caregivers compliance with personal protective equipment use in long-term care facilities.\u003c/p\u003e","manuscriptTitle":"An Outbreak of Norovirus in a Long-term Care Facility — Guangzhou City, Guangdong Province, China, December 2024","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-22 10:01:54","doi":"10.21203/rs.3.rs-7296110/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2025-12-17T06:03:59+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-09T14:10:57+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-10-23T03:03:39+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-20T12:06:25+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-08-15T02:08:08+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5af1b1aa-ccdc-4159-9892-6979b06003b8","owner":[],"postedDate":"December 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":59912372,"name":"Health sciences/Diseases"},{"id":59912373,"name":"Health sciences/Health care"},{"id":59912374,"name":"Health sciences/Medical research"},{"id":59912375,"name":"Biological sciences/Microbiology"},{"id":59912376,"name":"Health sciences/Risk factors"}],"tags":[],"updatedAt":"2025-12-22T10:01:54+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-22 10:01:54","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7296110","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7296110","identity":"rs-7296110","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}