Epidemiology and high-level macrolide resistance of Mycoplasma pneumoniae among children in Hangzhou, China: a 2024–2025 single-center surveillance study

Epidemiology and high-level macrolide resistance of Mycoplasma pneumoniae among children in Hangzhou, China: a 2024–2025 single-center surveillance study | 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 Research Article Epidemiology and high-level macrolide resistance of Mycoplasma pneumoniae among children in Hangzhou, China: a 2024–2025 single-center surveillance study Xudong Xu¹, Xiangyang Xiao², Jun Zhou¹, Xinfeng Zhao¹ This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8782752/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective To analyze the epidemiological characteristics and macrolide resistance profile of Mycoplasma pneumoniae (MP) infections among children in Hangzhou during the post-COVID-19 period (2024–2025), providing evidence for precise clinical management. Methods We conducted a retrospective analysis of 12,380 respiratory specimens from patients at Hangzhou Children’s Hospital (March 2024 to December 2025). MP nucleic acid and the 23S rRNA A2063G/A2064G resistance mutations were detected using quantitative PCR. Positivity and resistance rates were analyzed across gender, age, care setting (inpatient/outpatient), and time. Results The overall MP positivity rate was 19.98% (2,473/12,380). Among positive cases, 86.94% (2,150/2,473) carried resistance mutations. Positivity rates did not differ significantly by gender (19.58% vs 20.41%, P > 0.05). However, outpatients had a significantly higher positivity rate than inpatients (29.96% vs 18.96%; χ²=74.32, P < 0.01), and a higher resistance rate (92.13% vs 86.10%; χ²=11.89, P < 0.01). Infection rates exhibited a unimodal age distribution, peaking in children aged 6–12 years (27.90%-39.08%). Resistance rates exceeded 78% across all age groups. In 2024, the monthly resistance rate fluctuated between 74.89% and 94.20%. Conclusion During 2024–2025, MP infections in children showed distinct age clustering, with school-aged children at highest risk. Macrolide resistance was alarmingly prevalent (> 85%) and particularly prominent in outpatients. These findings underscore the need for enhanced resistance surveillance and optimized antibiotic stewardship in pediatric and outpatient settings. Mycoplasma Pneumoniae Epidemiology Macrolides Drug Resistance Children Figures Figure 1 Figure 2 Introduction Mycoplasma pneumoniae(MP) is a major causative agent of community-acquired pneumonia (CAP) worldwide, with epidemics recurring every 3–5 years [ 1 ] . Alarmingly, macrolide resistance in MP has risen sharply, reaching 93.21% in some Chinese regions like Shandong Province (2020–2024) [ 2 ] , leading to increased treatment failures and healthcare burdens. The COVID-19 pandemic has significantly altered global respiratory pathogen dynamics, potentially affecting MP epidemiology. For instance, a notable increase in pediatric MP infection and resistance rates was reported in the Nanxun area post-pandemic [ 3 ] . However, comprehensive surveillance data on MP trends in the late/post-pandemic era remain limited. This study analyzes MP positivity and macrolide resistance mutations at Hangzhou Children's Hospital from 2024 to 2025, aiming to elucidate local epidemiological features and resistance trends, thereby informing regional MP pneumonia (MPP) control and antimicrobial stewardship strategies. 1. Materials and Methods 1.1 Study Design and Participants This retrospective study included 12,380 respiratory infection patients from Hangzhou Children's Hospital (March 2024-December 2025). Inclusion criteria were: (1) clinical diagnosis of CAP or suspected MP infection; (2) complete MP nucleic acid and resistance testing; (3) availability of complete clinical records. Exclusion criteria were: (1) age < 1 month; (2) severe comorbidities; (3) incomplete data. This study was approved by the Ethics Committee (Institutional Review Board) of Hangzhou Children's Hospital in accordance with the Declaration of Helsinki (Approval No.: IRB-2026-016 (IIT)). The requirement for informed consent was waived due to the retrospective nature of the study. 1.2 Laboratory Detection Nasopharyngeal swab or sputum samples were collected. Nucleic acids were extracted using a thermal lysis kit (DaAn Gene Co., Ltd., Guangzhou). MP P1 gene and the 23S rRNA A2063G/A2064G resistance mutations were detected via quantitative PCR (Mole Biotechnology Co., Ltd., Jiangsu) on an ABI-7500 Fast Dx system. A sample was considered MP-positive if the P1 gene Ct value was < 35.01, and resistant if the mutation Ct value was < 35.33. 1.3 Statistical Analysis Data were analyzed using R software (v4.4.2). Categorical variables are presented as frequencies (percentages). Group comparisons were performed using the Chi-square (χ²) test or Fisher's exact test, as appropriate. 2. Results 2.1 Overall Detection Rates Among 12,380 tested patients, 2,473 (19.98%) were MP-positive. Of these, 2,150 (86.94%) harbored macrolide resistance mutations (Table 1 ). Table 1 Overall detection of Mycoplasma pneumoniae(MP) and macrolide resistance mutations(2024–2025).* The resistance rate is calculated as the number of resistance-positive cases divided by the number of MP-positive cases within each subgroup. Indicator Number of Cases Proportion (%) Total Tested 12,380 100.00 MP-Positive 2,473 19.98 Resistance-Positive* 2,150 86.94 MP-Negative 9,907 80.02 2.2 Demographic and Clinical Characteristics Gender:No significant differences in positivity or resistance rates were observed between males (19.58%, 88.13%) and females (20.41%, 85.68%) (both P > 0.05) (Table 2 ).Care Setting:Outpatients had a significantly higher MP positivity rate (29.96% vs. 18.96%, P < 0.001) and resistance rate (92.13% vs. 86.10%, P < 0.001) compared to inpatients (Table 3 ). Table 2 Detection rates of MP and macrolide resistance by gender. * Resistance rate calculation as in Table 1 . Gender Tested (n) MP-Positive n (%) Resistance-Positive n (%)* Male 6,497 1,272 (19.58) 1,121 (88.13) Female 5,883 1,201 (20.41) 1,029 (85.68) Total 12,380 2,473 (19.98) 2,150 (86.94) Table 3 Detection rates of MP and macrolide resistance by care setting. * Resistance rate calculation as in Table 1 . Setting Tested (n) MP-Positive n (%) Resistance-Positive n (%)* Inpatient 11,235 2,130 (18.96) 1,834 (86.10) Outpatient 1,145 343 (29.96) 316 (92.13) Total 12,380 2,473 (19.98) 2,150 (86.94) 2.3 Age Distribution MP positivity showed a unimodal age distribution, lowest in infants 78%) across all ages, exceeding 85% in most groups aged 3–12 years (Table 4 , Fig. 1 ). Table 4 Detection rates of MP and macrolide resistance by age group.* Resistance rate calculation as in Table 1 . Age (years) Tested (n) MP-Positive n (%) Resistance-Positive n (%)* < 1 697 28 (4.02) 26 (92.86) 1 1,062 67 (6.31) 54 (80.60) 2 1,092 91 (8.33) 72 (79.12) 3 1,526 157 (10.29) 141 (89.81) 4 1,353 195 (14.41) 168 (86.15) 5 1,177 223 (18.95) 189 (84.75) 6 1,283 358 (27.90) 314 (87.71) 7 1,106 333 (30.11) 298 (89.49) 8 850 290 (34.12) 256 (88.28) 9 636 237 (37.26) 205 (86.50) 10 558 204 (36.56) 179 (87.75) 11 412 161 (39.08) 139 (86.34) 12 267 58 (21.72) 52 (89.66) 13 174 37 (21.26) 30 (81.08) 14 109 23 (21.10) 18 (78.26) 15 49 6 (12.24) 4 (66.67) 16 24 4 (16.67) 4 (100.00) 17 5 1 (20.00) 1 (100.00) 2.4 Temporal Trends In 2024, MP positivity peaked from March to July. Resistance rates that year ranged from 74.89% to 94.20%, with the highest in March-April (> 93%). Data from 2025 showed wider fluctuations (66.67%-100%), reaching 100% in April and June (Table 5 , Fig. 2 ). Table 5 Monthly detection rates of MP and macrolide resistance in 2024 and 2025. * Resistance rate calculation as in Table 1 . Month 2024: MP+ (n) 2024: Res+ (n) 2024: Res Rate (%) 2025: MP+ (n) 2025: Res+ (n) 2025: Res Rate (%) Jan -- -- -- 92 79 85.87 Feb -- -- -- 29 24 82.76 Mar 138 130 94.20 19 17 89.47 Apr 207 194 93.72 12 12 100.00 May 321 282 87.85 7 6 85.71 Jun 264 220 83.33 13 13 100.00 Jul 381 329 86.35 14 13 92.86 Aug 223 167 74.89 12 11 91.67 Sep 119 102 85.71 10 7 70.00 Oct 170 150 88.24 6 4 66.67 Nov 228 202 88.60 6 4 66.67 Dec 189 173 91.53 13 11 84.62 3. Discussion Our analysis of 12,380 pediatric patients reveals key features of the post-pandemic MP landscape in Hangzhou. The overall MP positivity rate (19.98%) is within the global range for CAP [ 6 ] but lower than recent reports from Shandong (64.58%) [ 2 ] and Fujian [ 5 ] , highlighting potential regional variations in post-COVID-19 respiratory pathogen circulation. Consistent with global patterns [ 2 , 5 , 7 ] , we found a pronounced age clustering, with school-aged children (6–12 years) at highest risk, likely due to school-based transmission and evolving immunity. Infants had the lowest rate, possibly protected by maternal antibodies and limited exposure. A critical finding is the significantly higher burden of infection and resistance in outpatients. Their higher positivity rate (29.96% vs. 18.96%) may reflect healthcare-seeking behavior for milder cases, while their elevated resistance rate (92.13% vs. 86.10%) strongly suggests empirical macrolide use in primary care is a key driver of resistance selection. This underscores an urgent need for improved diagnostic stewardship in outpatient settings. The macrolide resistance rate of 86.94% aligns with the alarming trends reported across China (e.g., 93.21% in Shandong [ 2 ] , 85% in Wuhan [ 7 ] ), confirming the dominance of the A2063G mutation [ 4 ] . Resistance remained persistently high across all pediatric ages (> 78%), indicating entrenched circulation of resistant strains, potentially aided by the fitness advantages suggested for some resistant clones [ 8 ] . Notably, we observed monthly resistance rates up to 100% in early 2025, a stark warning. Such high rates may be associated with more severe clinical presentations [ 4 ] , though our study design limits clinical correlation analysis. Study Limitations :This single-center, retrospective design may limit generalizability. We lacked data on asymptomatic carriers, primary care cases, clinical outcomes, and alternative resistance mechanisms (e.g.,ermB). 4 Conclusions and Implications In post-pandemic Hangzhou, MP infections predominantly affect school-aged children and are characterized by severe and widespread macrolide resistance, especially among outpatients. Our findings advocate for: (1) enhanced surveillance focused on school-aged children and outpatient settings; (2) the integration of rapid molecular resistance testing into clinical practice to guide antibiotic selection; and (3) the implementation of robust antimicrobial stewardship programs. Abbreviations MP Mycoplasma pneumoniae CAP Community-acquired pneumonia PCR Polymerase chain reaction IRB Institutional Review Board MPP Mycoplasma pneumoniae pneumonia Ct Cycle threshold Declarations Ethics approval and consent to participate This retrospective study was reviewed and approved by the Ethics Committee (Institutional Review Board) of Hangzhou Children's Hospital (Approval No.: IRB 2026 016 (IIT)) in accordance with the Declaration of Helsinki. The requirement for informed consent was waived due to the retrospective nature of the study. Human Ethics declaration This study was conducted in accordance with the Declaration of Helsinki. Consent to participate Not applicable. (Waiver granted by the Ethics Committee as above.) Consent for publication Not applicable. No individual person's data in any form are presented. Funding This study received no specific grant from any funding agency in the public, commercial, or not for profit sectors. Competing interests The authors have no relevant financial or non financial interests to disclose. Author contributions Xudong Xu: Conceptualization, Data curation, Formal analysis, Writing – original draft. Xiangyang Xiao: Methodology, Resources, Validation. Jun Zhou: Investigation, Software, Data curation. Xinfeng Zhao: Supervision, Project administration, Writing – review & editing. Data availability The datasets generated and analyzed during the current study are not publicly available due to patient privacy and confidentiality agreements but are available from the corresponding author on reasonable request. References Xu HP, Ma XB. Progress and prospects in the pathogenic mechanism and clinical treatment of Mycoplasma pneumoniae[J]. World Notes Antibiot. 2026;47(1):1–8. Lu QF, Si YQ, Chu FL, et al. Epidemiological characteristics and drug resistance of Mycoplasma pneumoniaeinfection in a hospital in Shandong Province, 2020–2024 [J]. Prog Microbiol Immunol. 2025;53(5):69–74. Pan RQ, Meng J, Song JZ. Analysis of epidemiological characteristics and resistance mutation rate of MP infection in children in Nanxun area, 2022–2023 [J]. Gen Pract Investig. 2024;(9):1–4. Yu C, Lü W, Zhang XY. Relationship between clinical phenotype and chest imaging in children with community-acquired pneumonia with MP 23S rRNA A2063G gene variation [J]. J Clin Pediatr. 2021;39(4):1–4. Cai L, Gao XM, Wang ZJ, et al. Distribution and epidemiological characteristics of non-bacterial pathogens in children with acute respiratory infections at 10 regional pediatric medical centers in Fujian Province, 2023–2024 [J]. Chin J Nosocomiol. 2026;36(7):1–6. Wang S, Deng Y, Zheng J, et al. A2063G mutant strain as primary pathogen of Mycoplasma pneumoniaein children in Wuhan, China, 2023 [J]. Int J Infect Dis. 2024;145:107–12. Zhang BQ, Ou ST, Fan CP. Correlation between A2063G and A2064G mutations at site V of the 23S ribosomal RNA domain and refractoryMycoplasma pneumoniaepneumonia in children [J]. Guangxi Med J. 2022;44(13):1445–8. Zhang Z, Dou H, Yuan Q, et al. Proteomic and phenotypic studies of Mycoplasma pneumoniaerevealed macrolide-resistant mutation (A2063G) associated changes in protein composition and pathogenicity of type I strains [J]. Microbiol Spectr. 2023;11(4):e00323–23. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8782752","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":601320549,"identity":"6d329e76-5365-42a6-bb33-a43edc6a85cd","order_by":0,"name":"Xudong Xu¹","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAArUlEQVRIiWNgGAWjYHACAyCyseMnRYthA0NBWrJkA2laPhxm3HCAaFfdSN7+4IcBM7Px8eQNDD8qthHWItlzrLCxx4CNz+zMswLGnjO3CWvhZ+8xbGYw4GE2u5FjwMzYRoQWNmYekBYJxs0ziNUCtcWAcYMEsVpAfpnZY5CQLAH0y0Gi/AIMsQ0ffvz5b8ffnrzxwY8KIrQggQSDAySpB2shVccoGAWjYBSMEAAAl3c68/hOtrYAAAAASUVORK5CYII=","orcid":"","institution":"hangzhou children's hospital","correspondingAuthor":true,"prefix":"","firstName":"Xudong","middleName":"","lastName":"Xu¹","suffix":""},{"id":601320553,"identity":"e2acc585-61f3-414d-9f46-8305bd39d0c5","order_by":1,"name":"Xiangyang Xiao²","email":"","orcid":"","institution":"Hangzhou Hospital of Traditional Chinese Medicine","correspondingAuthor":false,"prefix":"","firstName":"Xiangyang","middleName":"","lastName":"Xiao²","suffix":""},{"id":601320557,"identity":"8b8e70fb-c90e-4272-adcf-b1d03fce7dcc","order_by":2,"name":"Jun Zhou¹","email":"","orcid":"","institution":"hangzhou children's hospital","correspondingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Zhou¹","suffix":""},{"id":601320559,"identity":"e250b84c-2da5-4350-b180-86de895de020","order_by":3,"name":"Xinfeng Zhao¹","email":"","orcid":"","institution":"hangzhou children's hospital","correspondingAuthor":false,"prefix":"","firstName":"Xinfeng","middleName":"","lastName":"Zhao¹","suffix":""}],"badges":[],"createdAt":"2026-02-04 06:53:38","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8782752/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8782752/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104205614,"identity":"caac5376-41e1-4bda-bcf5-7eeceac39c75","added_by":"auto","created_at":"2026-03-09 06:43:05","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":71443,"visible":true,"origin":"","legend":"\u003cp\u003eMP infection showed a unimodal age distribution. The positivity rate was lowest in infants \u0026lt;1 year (4.02%) and peaked in children aged 6-12 years (27.90%-39.08%).\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8782752/v1/7cddbe2348de5a5427c931d7.png"},{"id":104205601,"identity":"48a949a6-597a-4390-8697-9d2848662c9e","added_by":"auto","created_at":"2026-03-09 06:43:00","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":115560,"visible":true,"origin":"","legend":"\u003cp\u003eThe resistance rate remained high throughout the surveillance period (74.89%-100%), reaching 100% in April and June 2025.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8782752/v1/e7bd017b048bceac17bac25e.png"},{"id":104412933,"identity":"6456c4f3-2b38-4078-8868-6d45155b8a8f","added_by":"auto","created_at":"2026-03-11 13:02:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":865715,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8782752/v1/658171e3-4e73-42ea-9d1c-f100642b2426.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eEpidemiology and high-level macrolide resistance of Mycoplasma pneumoniae among children in Hangzhou, China: a 2024–2025 single-center surveillance study\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMycoplasma pneumoniae(MP) is a major causative agent of community-acquired pneumonia (CAP) worldwide, with epidemics recurring every 3\u0026ndash;5 years\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. Alarmingly, macrolide resistance in MP has risen sharply, reaching 93.21% in some Chinese regions like Shandong Province (2020\u0026ndash;2024)\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e, leading to increased treatment failures and healthcare burdens. The COVID-19 pandemic has significantly altered global respiratory pathogen dynamics, potentially affecting MP epidemiology. For instance, a notable increase in pediatric MP infection and resistance rates was reported in the Nanxun area post-pandemic\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. However, comprehensive surveillance data on MP trends in the late/post-pandemic era remain limited. This study analyzes MP positivity and macrolide resistance mutations at Hangzhou Children's Hospital from 2024 to 2025, aiming to elucidate local epidemiological features and resistance trends, thereby informing regional MP pneumonia (MPP) control and antimicrobial stewardship strategies.\u003c/p\u003e"},{"header":"1. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1.1 Study Design and Participants\u003c/h2\u003e \u003cp\u003eThis retrospective study included 12,380 respiratory infection patients from Hangzhou Children's Hospital (March 2024-December 2025). Inclusion criteria were: (1) clinical diagnosis of CAP or suspected MP infection; (2) complete MP nucleic acid and resistance testing; (3) availability of complete clinical records. Exclusion criteria were: (1) age\u0026thinsp;\u0026lt;\u0026thinsp;1 month; (2) severe comorbidities; (3) incomplete data.\u003c/p\u003e \u003cp\u003eThis study was approved by the Ethics Committee (Institutional Review Board) of Hangzhou Children's Hospital in accordance with the Declaration of Helsinki (Approval No.: IRB-2026-016 (IIT)). The requirement for informed consent was waived due to the retrospective nature of the study.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e1.2 Laboratory Detection\u003c/h2\u003e \u003cp\u003eNasopharyngeal swab or sputum samples were collected. Nucleic acids were extracted using a thermal lysis kit (DaAn Gene Co., Ltd., Guangzhou). MP P1 gene and the 23S rRNA A2063G/A2064G resistance mutations were detected via quantitative PCR (Mole Biotechnology Co., Ltd., Jiangsu) on an ABI-7500 Fast Dx system. A sample was considered MP-positive if the P1 gene Ct value was \u0026lt;\u0026thinsp;35.01, and resistant if the mutation Ct value was \u0026lt;\u0026thinsp;35.33.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e1.3 Statistical Analysis\u003c/h2\u003e \u003cp\u003eData were analyzed using R software (v4.4.2). Categorical variables are presented as frequencies (percentages). Group comparisons were performed using the Chi-square (χ\u0026sup2;) test or Fisher's exact test, as appropriate.\u003c/p\u003e \u003c/div\u003e"},{"header":"2. Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Overall Detection Rates\u003c/h2\u003e \u003cp\u003eAmong 12,380 tested patients, 2,473 (19.98%) were MP-positive. Of these, 2,150 (86.94%) harbored macrolide resistance mutations (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\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\u003eOverall detection of Mycoplasma pneumoniae(MP) and macrolide resistance mutations(2024\u0026ndash;2025).* The resistance rate is calculated as the number of resistance-positive cases divided by the number of MP-positive cases within each subgroup.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndicator\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\u003eProportion (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal Tested\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12,380\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e100.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMP-Positive\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2,473\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19.98\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResistance-Positive*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2,150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e86.94\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMP-Negative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9,907\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e80.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Demographic and Clinical Characteristics\u003c/h2\u003e \u003cp\u003eGender:No significant differences in positivity or resistance rates were observed between males (19.58%, 88.13%) and females (20.41%, 85.68%) (both \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).Care Setting:Outpatients had a significantly higher MP positivity rate (29.96% vs. 18.96%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and resistance rate (92.13% vs. 86.10%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) compared to inpatients (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\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\u003eDetection rates of MP and macrolide resistance by gender. * Resistance rate calculation as in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTested (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMP-Positive n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eResistance-Positive n (%)*\u003c/p\u003e \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=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6,497\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1,272 (19.58)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1,121 (88.13)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5,883\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1,201 (20.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1,029 (85.68)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12,380\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2,473 (19.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2,150 (86.94)\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\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDetection rates of MP and macrolide resistance by care setting. * Resistance rate calculation as in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSetting\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTested (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMP-Positive n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eResistance-Positive n (%)*\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInpatient\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e11,235\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2,130 (18.96)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1,834 (86.10)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutpatient\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,145\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e343 (29.96)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e316 (92.13)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12,380\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2,473 (19.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2,150 (86.94)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Age Distribution\u003c/h2\u003e \u003cp\u003eMP positivity showed a unimodal age distribution, lowest in infants\u0026thinsp;\u0026lt;\u0026thinsp;1 year (4.02%) and peaking at 6\u0026ndash;11 years (27.90%-39.08%). Resistance rates remained high (\u0026gt;\u0026thinsp;78%) across all ages, exceeding 85% in most groups aged 3\u0026ndash;12 years (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDetection rates of MP and macrolide resistance by age group.* Resistance rate calculation as in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTested (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMP-Positive n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eResistance-Positive n (%)*\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e697\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e28 (4.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e26 (92.86)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,062\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e67 (6.31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e54 (80.60)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,092\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e91 (8.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e72 (79.12)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,526\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e157 (10.29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e141 (89.81)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,353\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e195 (14.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e168 (86.15)\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\u003e1,177\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e223 (18.95)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e189 (84.75)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,283\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e358 (27.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e314 (87.71)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,106\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e333 (30.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e298 (89.49)\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\u003e850\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e290 (34.12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e256 (88.28)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e636\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e237 (37.26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e205 (86.50)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e558\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e204 (36.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e179 (87.75)\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\u003e412\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e161 (39.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e139 (86.34)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e267\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e58 (21.72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e52 (89.66)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e174\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e37 (21.26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30 (81.08)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e109\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23 (21.10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e18 (78.26)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6 (12.24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4 (66.67)\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\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4 (16.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4 (100.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\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\u003e1 (20.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1 (100.00)\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\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Temporal Trends\u003c/h2\u003e \u003cp\u003eIn 2024, MP positivity peaked from March to July. Resistance rates that year ranged from 74.89% to 94.20%, with the highest in March-April (\u0026gt;\u0026thinsp;93%). Data from 2025 showed wider fluctuations (66.67%-100%), reaching 100% in April and June (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMonthly detection rates of MP and macrolide resistance in 2024 and 2025. * Resistance rate calculation as in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\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=\"char\" char=\".\" 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=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMonth\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2024: MP+ (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2024: Res+ (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2024: Res Rate (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2025: MP+ (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2025: Res+ (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2025: Res Rate (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e--\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e--\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e--\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e85.87\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFeb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e--\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e--\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e--\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e82.76\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMar\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e138\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e130\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e94.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e89.47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e207\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e194\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e93.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e100.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMay\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e321\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e282\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e87.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e85.71\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJun\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e264\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e220\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e83.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e100.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJul\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e381\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e329\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e86.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e92.86\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAug\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e223\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e167\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e74.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e91.67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSep\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e119\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e102\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e85.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e70.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e170\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e88.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e66.67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNov\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e228\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e202\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e88.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e66.67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDec\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e189\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e173\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e91.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.62\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\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"3. Discussion","content":"\u003cp\u003eOur analysis of 12,380 pediatric patients reveals key features of the post-pandemic MP landscape in Hangzhou. The overall MP positivity rate (19.98%) is within the global range for CAP\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e but lower than recent reports from Shandong (64.58%)\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e and Fujian\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e, highlighting potential regional variations in post-COVID-19 respiratory pathogen circulation.\u003c/p\u003e \u003cp\u003eConsistent with global patterns\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e, we found a pronounced age clustering, with school-aged children (6\u0026ndash;12 years) at highest risk, likely due to school-based transmission and evolving immunity. Infants had the lowest rate, possibly protected by maternal antibodies and limited exposure.\u003c/p\u003e \u003cp\u003eA critical finding is the significantly higher burden of infection and resistance in outpatients. Their higher positivity rate (29.96% vs. 18.96%) may reflect healthcare-seeking behavior for milder cases, while their elevated resistance rate (92.13% vs. 86.10%) strongly suggests empirical macrolide use in primary care is a key driver of resistance selection. This underscores an urgent need for improved diagnostic stewardship in outpatient settings.\u003c/p\u003e \u003cp\u003eThe macrolide resistance rate of 86.94% aligns with the alarming trends reported across China (e.g., 93.21% in Shandong\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e, 85% in Wuhan\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e), confirming the dominance of the A2063G mutation\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. Resistance remained persistently high across all pediatric ages (\u0026gt;\u0026thinsp;78%), indicating entrenched circulation of resistant strains, potentially aided by the fitness advantages suggested for some resistant clones \u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eNotably, we observed monthly resistance rates up to 100% in early 2025, a stark warning. Such high rates may be associated with more severe clinical presentations\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e, though our study design limits clinical correlation analysis.\u003c/p\u003e \u003cp\u003e \u003cb\u003eStudy Limitations\u003c/b\u003e:This single-center, retrospective design may limit generalizability. We lacked data on asymptomatic carriers, primary care cases, clinical outcomes, and alternative resistance mechanisms (e.g.,ermB).\u003c/p\u003e"},{"header":"4 Conclusions and Implications","content":"\u003cp\u003eIn post-pandemic Hangzhou, MP infections predominantly affect school-aged children and are characterized by severe and widespread macrolide resistance, especially among outpatients. Our findings advocate for: (1) enhanced surveillance focused on school-aged children and outpatient settings; (2) the integration of rapid molecular resistance testing into clinical practice to guide antibiotic selection; and (3) the implementation of robust antimicrobial stewardship programs.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMycoplasma pneumoniae\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCAP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCommunity-acquired pneumonia\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePCR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePolymerase chain reaction\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIRB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInstitutional Review Board\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMPP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMycoplasma pneumoniae\u0026nbsp;pneumonia\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCt\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCycle threshold\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eThis retrospective study was reviewed and approved by the Ethics Committee (Institutional Review Board) of Hangzhou Children\u0026apos;s Hospital (Approval No.: IRB 2026 016 (IIT)) in accordance with the Declaration of Helsinki. The requirement for informed consent was waived due to the retrospective nature of the study.\u003c/p\u003e\n\u003cp\u003eHuman Ethics declaration\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003eConsent to participate\u003c/p\u003e\n\u003cp\u003eNot applicable. (Waiver granted by the Ethics Committee as above.)\u003c/p\u003e\n\u003cp\u003eConsent for publication\u003c/p\u003e\n\u003cp\u003eNot applicable. No individual person\u0026apos;s data in any form are presented.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis study received no specific grant from any funding agency in the public, commercial, or not for profit sectors.\u003c/p\u003e\n\u003cp\u003eCompeting interests\u003c/p\u003e\n\u003cp\u003eThe authors have no relevant financial or non financial interests to disclose.\u003c/p\u003e\n\u003cp\u003eAuthor contributions\u003c/p\u003e\n\u003cp\u003eXudong Xu: Conceptualization, Data curation, Formal analysis, Writing \u0026ndash; original draft.\u003c/p\u003e\n\u003cp\u003eXiangyang Xiao: Methodology, Resources, Validation.\u003c/p\u003e\n\u003cp\u003eJun Zhou: Investigation, Software, Data curation.\u003c/p\u003e\n\u003cp\u003eXinfeng Zhao: Supervision, Project administration, Writing \u0026ndash; review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003eData availability\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current study are not publicly available due to patient privacy and confidentiality agreements but are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eXu HP, Ma XB. Progress and prospects in the pathogenic mechanism and clinical treatment of Mycoplasma pneumoniae[J]. World Notes Antibiot. 2026;47(1):1\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLu QF, Si YQ, Chu FL, et al. Epidemiological characteristics and drug resistance of Mycoplasma pneumoniaeinfection in a hospital in Shandong Province, 2020\u0026ndash;2024 [J]. Prog Microbiol Immunol. 2025;53(5):69\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePan RQ, Meng J, Song JZ. Analysis of epidemiological characteristics and resistance mutation rate of MP infection in children in Nanxun area, 2022\u0026ndash;2023 [J]. Gen Pract Investig. 2024;(9):1\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu C, L\u0026uuml; W, Zhang XY. Relationship between clinical phenotype and chest imaging in children with community-acquired pneumonia with MP 23S rRNA A2063G gene variation [J]. J Clin Pediatr. 2021;39(4):1\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCai L, Gao XM, Wang ZJ, et al. Distribution and epidemiological characteristics of non-bacterial pathogens in children with acute respiratory infections at 10 regional pediatric medical centers in Fujian Province, 2023\u0026ndash;2024 [J]. Chin J Nosocomiol. 2026;36(7):1\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang S, Deng Y, Zheng J, et al. A2063G mutant strain as primary pathogen of Mycoplasma pneumoniaein children in Wuhan, China, 2023 [J]. Int J Infect Dis. 2024;145:107\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang BQ, Ou ST, Fan CP. Correlation between A2063G and A2064G mutations at site V of the 23S ribosomal RNA domain and refractoryMycoplasma pneumoniaepneumonia in children [J]. Guangxi Med J. 2022;44(13):1445\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang Z, Dou H, Yuan Q, et al. Proteomic and phenotypic studies of Mycoplasma pneumoniaerevealed macrolide-resistant mutation (A2063G) associated changes in protein composition and pathogenicity of type I strains [J]. Microbiol Spectr. 2023;11(4):e00323\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Mycoplasma Pneumoniae, Epidemiology, Macrolides, Drug Resistance, Children","lastPublishedDoi":"10.21203/rs.3.rs-8782752/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8782752/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eTo analyze the epidemiological characteristics and macrolide resistance profile of \u003cem\u003eMycoplasma pneumoniae\u003c/em\u003e (MP) infections among children in Hangzhou during the post-COVID-19 period (2024\u0026ndash;2025), providing evidence for precise clinical management.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe conducted a retrospective analysis of 12,380 respiratory specimens from patients at Hangzhou Children\u0026rsquo;s Hospital (March 2024 to December 2025). MP nucleic acid and the 23S rRNA A2063G/A2064G resistance mutations were detected using quantitative PCR. Positivity and resistance rates were analyzed across gender, age, care setting (inpatient/outpatient), and time.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe overall MP positivity rate was 19.98% (2,473/12,380). Among positive cases, 86.94% (2,150/2,473) carried resistance mutations. Positivity rates did not differ significantly by gender (19.58% vs 20.41%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). However, outpatients had a significantly higher positivity rate than inpatients (29.96% vs 18.96%; χ\u0026sup2;=74.32, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), and a higher resistance rate (92.13% vs 86.10%; χ\u0026sup2;=11.89, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01). Infection rates exhibited a unimodal age distribution, peaking in children aged 6\u0026ndash;12 years (27.90%-39.08%). Resistance rates exceeded 78% across all age groups. In 2024, the monthly resistance rate fluctuated between 74.89% and 94.20%.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eDuring 2024\u0026ndash;2025, MP infections in children showed distinct age clustering, with school-aged children at highest risk. Macrolide resistance was alarmingly prevalent (\u0026gt;\u0026thinsp;85%) and particularly prominent in outpatients. These findings underscore the need for enhanced resistance surveillance and optimized antibiotic stewardship in pediatric and outpatient settings.\u003c/p\u003e","manuscriptTitle":"Epidemiology and high-level macrolide resistance of Mycoplasma pneumoniae among children in Hangzhou, China: a 2024–2025 single-center surveillance study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-09 06:42:15","doi":"10.21203/rs.3.rs-8782752/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b40d5437-0d0b-4c9b-be19-43ab4c819a85","owner":[],"postedDate":"March 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-11T12:21:21+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-09 06:42:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8782752","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8782752","identity":"rs-8782752","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}