Group B streptococcus colonization in pregnancy and neonatal outcomes: a three-year monocentric retrospective study during and after the COVID-19 pandemic

Group B streptococcus colonization in pregnancy and neonatal outcomes: a three-year monocentric retrospective study during and after the COVID-19 pandemic | 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 Group B streptococcus colonization in pregnancy and neonatal outcomes: a three-year monocentric retrospective study during and after the COVID-19 pandemic Gregorio Serra, Lucia Lo Scalzo, Maria Giordano, Mario Giuffrè, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4189394/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 13 Sep, 2024 Read the published version in Italian Journal of Pediatrics → Version 1 posted 4 You are reading this latest preprint version Abstract Background Group B Streptococcus (GBS) is a major cause of sepsis and meningitis in newborns. The Centers for Disease Control and Prevention (CDC) recommends to pregnant women, between 35 and 37 weeks of gestation, universal vaginal-rectal screening for GBS colonization, aimed at intrapartum antibiotic prophylaxis (IAP). The latter is the only currently available and highly effective method against GBS neonatal infections. Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, the preventive measures implemented to mitigate the effects of SARS-CoV-2 infection led to the reduction in the access to many health facilities and services, including the obstetric and perinatal ones. The purpose of the present study was to evaluate the prevalence rates of maternal GBS colonization, as well as use and effects of IAP in the newborn, in a population of pregnant women during (years 2020–2021) and after (year 2022) the COVID-19 pandemic, also with the aim to establish possible epidemiological and clinical differences in the two subjects’ groups. Methods We retrospectively analyzed the clinical data of pregnant women admitted to, and delivering, at the Gynaecology and Obstetrics Unit, Department of Sciences for Health Promotion and Mother and Child Care, of the University Hospital of Palermo, Italy, from 01.01.2020 to 31.12.2022. For each of them, we recorded pertinent socio-demographic information, clinical data related to pregnancy, delivery and peripartum , and specifically execution and status of vaginal and rectal swab test for GBS detection, along with eventual administration and modality of IAP. The neonatal outcome was investigated in all cases at risk. The data observed during the pandemic (years 2020–2021) were compared with those recorded in the following period (year 2022). Results The present analysis involved 2109 pregnant women, in addition to their 2144 newborns. The vaginal-rectal swab for GBS was performed in 1559 (73.92%) individuals. The test resulted positive in 178 cases overall (11.42% of those undergoing the screening). Amongst our whole sample, 298 women had an indication for IAP, and 64 (21.48%) received adequate treatment; for 23 (7.72%) it was inadequate/incomplete, while 211 (70.8%) did not receive IAP. Comparing the pandemic period (years 2020–2021) with the following one (year 2022), a lower incidence ( p = 0.009 ) in the execution of vaginal-rectal swabs for GBS was found (70.38% during vs 75.65% after) in the first two years, while a greater number (although not statistically significant, p = 0.12) of adequate and complete IAP conducted in 2022, than in the previous biennium (26.36 vs 18.62%). During the study time, 13 neonates with early onset disease (EOD), out of 179 (7.3%) born to mothers with risk factors, were observed (the global prevalence on the total of babies delivered in the period under investigation was 6.06‰). 3 among these patients’ mothers performed incomplete IAP, while the others did not receive IAP. Neither cases of neonatal meningitis, nor deaths were observed. Conclusions The present study revealed in our Department an increased prevalence of pregnant women screened for, and colonized by GBS, in the last decade. However, a significantly lower frequency of vaginal-rectal swabs performed for GBS, as well as a smaller number of adequate and complete IAP were found in the pandemic biennium (2020–2021) than in the following year (2022). Such data are in accordance with those observed during the pandemic period for other care settings, where significant delays in diagnosis and treatment and increased mortality/morbidity rates, due to the indirect effects of COVID-19, have been described. Although IAP is an easy procedure to implement, however adherence and uniformity in the management protocols are still not optimal. In addition, significant EOD prevalence has been reported among children of mothers carrying risk factors. Therefore, the prophylactic measures adopted to date cannot be considered fully satisfactory, and should be improved. Better skills integration and obstetrical-neonatological collaboration, in addition to new effective preventive tools, like vaccines able to prevent invasive disease, may allow further reduction in morbidity and mortality rates related to GBS perinatal infection. Streptococcus agalactiae GBS colonization intrapartum antibiotic prophylaxis neonatal sepsis COVID-19 Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Background Group B Streptococcus (GBS), also known as Streptococcus agalactiae for its causative role in bovine mastitis, is present in the genitourinary and gastrointestinal tracts of pregnant women. Maternal GBS colonization rates vary worldwide from 10 to 40%, with mean prevalence of 18% [ 1 – 3 ]. The infection may cause asymptomatic bacteriuria, as well as urinary tract infections like pyelonephritis, and also chorioamnionitis, postpartum endometritis, pneumonia and puerperal sepsis. It may also be responsible for miscarriage, as well as preterm birth and premature rupture of membranes (PROM) [ 4 , 5 ]. In the newborn, GBS infection has bimodal distribution, giving rise to both early (EOD) and late onset diseases (LOD). EOD is generally acquired by vertical transmission and occurs within 24 hours after birth in the 60–80% of cases, within 72 hours in the 90%, but can manifest at any time during the first week of life. The most common clinical pictures of EOD include sepsis, pneumonia and meningitis. LOD, conversely, may be observed between 7 and 90 days of life, and the association with maternal colonization is not as strong as for EOD [ 6 , 7 ]. The Centers for Disease Control and Prevention (CDC) recommends for pregnant women, between 35 and 37 weeks of gestation, universal vaginal-rectal screening for GBS colonization [ 8 ]. Furthermore, intrapartum antibiotic prophylaxis (IAP) administrated ≥ 4 h before delivery is the only currently available and highly effective method against GBS neonatal infections, resulting in a reduction in the incidence of EOD of more than 80%, from 1.8 newborns per 1,000 live births in the 1990s to 0.23 newborns per 1,000 live births in 2015, although not being able to limit the impact of LOD [ 9 ]. Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, more than 6.9 million people died worldwide due to SARS-CoV-2 infection [ 10 ]. In Italy, it has been associated with significant clinical and psychological effects, also in pregnant women. Indeed, the infection control and the preventive measures (social distancing, mask wearing, hand hygiene and quarantine) implemented to mitigate the effects of the pandemic, led to the reduction in the access to many health facilities and services, including the obstetric and perinatal ones. Such decrease was linked both to the difficulties encountered by people in keeping the support from other family members within the hospital, and to the fear of contracting the infection [ 11 , 12 ]. The purpose of the present study was to retrospectively evaluate the prevalence rates of maternal vaginal-rectal GBS colonization, as well as use and effects of IAP in the newborn, in a population of pregnant women during (years 2020–2021) and after (year 2022) the COVID-19 pandemic, also with the aim to establish possible epidemiological and clinical differences in the two subjects’ groups. Methods We retrospectively analyzed the clinical data of pregnant women admitted to, and delivering, at the Gynaecology and Obstetrics Unit, Department of Sciences for Health Promotion and Mother and Child Care, of the University Hospital of Palermo, Italy, from 01.01.2020 to 31.12.2022. For each of them, we recorded the pertinent socio-demographic information, and the clinical data related to pregnancy, delivery and peripartum , and specifically: age at delivery; nationality; residence; occupation; execution and status of vaginal and rectal swab test for GBS detection between 35 and 37 weeks of gestation; type of delivery (i.e., vaginal, elective or emergency cesarean section); premature rupture of membranes (PROM, ≥ 18 h before delivery); eventual IAP. We considered the results of vaginal and rectal swabs for GBS, performed between weeks 35 + 0 and 37 + 0 of gestation. This procedure is usually performed routinely in our Hospital in such time window, according to the indications of the CDC [ 8 , 13 ]. Specifically, IAP was recommended in women with a positive GBS screening culture (excluding those undergoing cesarean delivery with intact amniotic membranes before labor onset), a previous child with GBS disease, bacteriuria documenting GBS in the current pregnancy, and in those with unknown GBS status at labor onset and at least one of the following risk factors: delivery at < 37 weeks’ gestation, amniotic membranes rupture ≥ 18 hours and/or intrapartum temperature ≥ 38.0°C [ 14 – 16 ]. However, many variations of practice, based on the individual gynecologist and/or on mother’s compliance, have been observed during the study period in our sample population. Ampicillin was the first-line drug used, and it was administered intravenously (IV) at the dose of 2 g, followed by 1 g IV every 4 h until delivery. Cefazolin was the option chosen for women allergic to penicillin but not at high risk for anaphylaxis, while clindamycin or vancomycin have been used for high risk of anaphylaxis to penicillin, according to guidelines [ 17 , 18 ]. IAP was considered adequate and complete when administered ≥ 4 h before delivery [ 8 ]. We focused on the rate of patients undergoing GBS screening, and on those with positive GBS screening tests. We also evaluated the indications for IAP, as well as the modality of IAP execution (if either adequate/complete or not). The neonatal outcome was investigated in all cases at risk and, in particular, we analyzed for each newborn: sex; gestational age; Apgar scores at 1 and 5 minutes; weight, length and occipitofrontal circumference at birth, and respective percentiles; respiratory, metabolic and systemic disturbances; neurological manifestations and/or feeding problems; blood cell count; C reactive protein (CRP) and/or procalcitonin (PCT) values; blood culture results; eventual admission to neonatal intensive care unit (NICU); eventual intravenous antibiotic therapy, its duration, and type of drugs used. The data observed during the pandemic (years 2020–2021) were compared with those recorded in the following period (year 2022). Statistical analysis We used R version 4.0.4 (R Foundation for Statistical Computing, Vienna, Austria) for data analysis. Simple descriptive statistics were expressed as frequency and percentage for categorical variables, mean and standard deviation for continuous variables. Paired-samples t-test was used to compare data on the vaginal-rectal GBS colonization rate, as well as use of IAP and its effects on neonatal outcomes during (years 2020–2021) and after (year 2022) the COVID-19 pandemic. A p value lower than 0.05 was considered statistically significant. Results Socio-demographic information, and clinical data related to pregnancy, delivery and peripartum The total number of deliveries observed during the study period was 2315, including 35 twin births (all bigeminal). The medical records were not available for 206 mothers, and therefore the present analysis involved 2109 pregnant women, in addition to their 2144 newborns. Evaluated by year, the total number of delivering women was as follows: 660 in 2020, 757 in 2021, and 692 in 2022. There were 141 preterm (< 37 weeks of gestational age) deliveries, while the other 1968 were full-term ones. In the population under investigation, the average age was 30.42 ± 6 years, ranging between 15 and 52. Foreign mothers, defined as those who were not born in Italy, were the 12.94%. The most frequent countries of birth were Bangladesh (40.2%), Nigeria (15.01%), Morocco (7.69%), Romania (7.47%) and Tunisia (5.1%). The 69.41% of participants were resident in urban areas, while 30.59% came from rural ones. In regard with mothers’ occupation, 73.82% were housewives, 14.22% employees, 10.38% freelance professionals and 1.57% craftswomen/tradeswomen. In our sample, 1004 women (47.61%) had vaginal deliveries, while 650 (30.82%) and 455 (21.57%) underwent elective and emergency cesarean sections, respectively. 779 participants (36.94%) were primiparous. Prevalence rates of maternal GBS colonization and use of IAP The vaginal-rectal swab for GBS was performed in 1559 (73.92%) individuals. More precisely, 512 were carried out in 2020, 560 in 2021 and 487 in 2022 (Fig. 1a /b ). Figure 1a/b . Number of swabs performed during the study period (expressed in absolute values and percentages) (a) , and divided by year (b) The test resulted positive in 178 cases overall (11.42% of those undergoing the screening): 56 were those in 2020, 66 in 2021, and 56 in 2022 (Fig. 2a /b ). Figure 2a/b . Results of the performed swabs (a) , and number of positive ones divided by year (b) Among GBS-positive patients, 41 (23.03%) received complete IAP, while to 20 (11.24%) an incomplete IAP was administered. 48 women (26.97%) did not receive IAP, due to cesarean sections performed before the onset of labor and with intact amniotic membranes; 69 subjects (38.76%), conversely, did not undergo IAP despite the presence of one or more clinical indications (Fig. 3). Figure 3 . Intrapartum antibiotic prophylaxis administration profiles in our population of pregnant women Of the 550 (26.08%) pregnant women with unknown GBS colonization status, 120 (21.82%) had intrapartum risk factors. In this group, preterm delivery (< 37 weeks of gestation) was the only risk condition in 65 patients (11.82%), PROM ≥ 18 hours in 43 (7.82%), while 12 (2.18%) of them had both risk factors (preterm delivery and PROM ≥ 18 hours). No women presented with fever and/or other signs of chorioamnionitis. Considering only the individuals with intrapartum risk factors, 23 (19.17%) received complete IAP, the prophylaxis was incomplete in 3 (2.5%) cases, and for 94 (78.33%) it was not administered. Amongst our overall sample, 298 women had an indication for IAP (Fig. 4a), and 64 (21.48%) received adequate treatment; for 23 (7.72%) it was inadequate/incomplete, while 211 (70.8%) did not receive IAP (Fig. 4b). Most cases where the prophylaxis was indicated, but in which it was not performed or was inadequate/incomplete, were represented by pregnant women admitted to hospital in advanced labor or presenting with precipitous delivery. In a few subjects IAP was simply omitted, probably for misinterpreted/incorrect data on GBS swabs at the time of birth. Figure 4a/b . Overall number and rates of pregnant women with and without indications for IAP administration (a) , and IAP profiles in those with intrapartum risk factors (b) Comparing the Italian mothers with the foreign ones, a higher incidence ( p < 0.0001 ) in the execution of vaginal-rectal swabs for GBS was found in the period under investigation among the former (75.49% vs 63.37%), as well as a greater number (although not statistically significant, p = 0.72) of adequate and complete IAP (21.86% vs 19.61%). Conversely, the rate of positive GBS swabs was significantly higher among the foreign mothers (10.46% in the group of Italian women vs 19.08% in the latter, p = 0.0008). Comparing the pandemic period (years 2020–2021) with the following one (year 2022), a lower incidence ( p = 0.009 ) in the execution of vaginal-rectal swabs for GBS was found in the first two years (70.38% during vs 75.65% after the COVID-19 pandemic; Fig. 5a ), while a greater number (although not statistically significant, p = 0.12) of adequate and complete IAP conducted in 2022, than in the previous biennium (26.36 vs 18.62%; Fig. 5b ). Finally, the comparison between the periods during and after COVID-19 revealed a mildly lower (without statistical significance, p = 0.94) GBS colonization rate during the pandemic than the following year (11.38% vs 11.5%; Fig. 5c ). Figure 5a/b/c . Comparison of swabs performed (a) , IAP administration (b) and maternal GBS colonization (c) rates between the pandemic period (years 2020–2021) and the following one (year 2022) Effects of maternal GBS colonization in the newborn During the study period, 13 neonates with EOD, out of 179 (7.3%) born to mothers with risk factors (including overall those showing positive, negative, and unknown GBS status, i.e. 60, 11 and 108 respectively), were observed (the global prevalence on the total of babies delivered in the period under investigation was 6.06‰) (Fig. 6a). Among them, 9 were male and 4 female. Mean gestational age was 39 + 4 weeks. All babies had normal Apgar scores (> 7) at 1 and 5 minutes. The average birth weight was 3249 ± 482 g, length 49.6 ± 2.7 cm, and occipitofrontal circumference 34.0 ± 1.5 cm. 2 of them were small for gestational age (SGA), while 11 were appropriate for gestational age (AGA). 3 among these patients’ mothers performed incomplete IAP, while the others did not receive IAP (Fig. 6b). Figure 6a/b. Overall number and rates of neonates with and without EOD born to women with risk factors (a) , and IAP profiles in the mothers of EOD newborns (b) Clinical manifestations included septic shock (1), jaundice (1), respiratory distress (4), feeding difficulties/regurgitation associated with hypotonia (6), while hyperpyrexia was present in 1 case (Fig. 7) . Figure 7 . Clinical manifestations of EOD neonates Increased inflammation indices (CRP and/or PCT) were detected in all newborns. Blood cultures were carried out in all subjects before the start of antibiotic therapy, and resulted negative in all cases. 4 subjects required hospitalization in the NICU, while in 9 cases the admission to the Neonatal Pathology Unit (sub-intensive care setting) was necessary. The patients were hospitalized for an average of 11 ± 3 days. The mean duration of antibiotic therapy was 7 ± 3 days. Empiric therapy with ampicillin (100 mg/kg/dose every 12 hours) and gentamicin (4 mg/kg/dose every 24 hours) was promptly started in all neonates. The antimicrobial treatment was continued until clinical symptoms disappeared, as well as complete blood counts, inflammation indices, and blood culture tests gave normal/negative results. There was no evidence of meningitis in any case, and no deaths were observed. Comparing the pandemic period (years 2020–2021) with the following one (year 2022), a higher rate (not statistically significant, p = 0.53) of EOD was found in the first two years of the study (8.06% vs 5.45%). Discussion Group B Streptococcus is a major cause of invasive infections in neonates, with the colonization of the vaginal-rectal tract of pregnant women being the main transmission source. Our data provide updated insights about the prevalence of vaginal-rectal GBS colonization in pregnancy. In addition, the present study shows the rates of adhesion to GBS screening and to IAP in a cohort of pregnant women referring to a II level University Hospital in the city of Palermo, Italy. In our sample, the prevalence of subjects screened for GBS out of the total addressed to our Mother and Child Department was 73.92%; complete vaginal–rectal screening for GBS was conducted in all cases. Such data were higher than those of a previous retrospective study carried out in our Hospital in 2012, and also than the rates recorded by Berardi A. et al. in 2011 in Central Italy, which were 66.03% and 67.9% respectively (Fig. 8a) [ 19 , 20 ]. According with CDC and the Italian Obstetrics Society guidelines, the execution of vaginal–rectal cultures for GBS is recommended between 35 and 37 weeks of gestation, and such indications were those followed also in the present study [ 8 , 13 ]. In our population vaginal and rectal swabs were positive for GBS in the 10.42% of cases; this value is at the lower range of the national average, which is between 10 and 20% [ 21 ]. Comparing the current analysis with that carried out in 2012 in our Hospital, an increased prevalence of GBS colonization in our population has been observed in the last few years (from 7.98–11.42%) (Fig. 8b) [ 19 ]. Figure 8a/b . Comparison of GBS screening among the current study and those previously reported in our Hospital and in Central Italy (a) , and of maternal GBS colonization between present analysis and that conducted by Puccio et al. in 2012 in our Department (b) Worldwide, frequencies of maternal GBS carriers have been reported to range from 14 to 30% in high-income countries (mildly higher than the present survey), to be around 19% in the Sub-Saharan region, and 12–15% in India and Pakistan (Fig. 9) [ 22 – 24 ]. Differences in the detected rate of vaginal-rectal GBS colonization may reflect the different demographic characteristics of the populations under investigation. Actually, GBS incidence rates can vary, either according to geographical region or time period [ 25 ]. Indeed, when comparing COVID-19 with the post-pandemic scenario , we detected a mild decrease in GBS maternal colonization during the years 2020–2021 (11.38% vs 11.5%). Figure 9 . Comparison of maternal GBS colonization rates among current study and those reported in other regions worldwide Amongst our overall sample, only 21.48% women received adequate IAP in presence of clinical indications (positive GBS screening culture or intrapartum risk factors). The consequent higher rate of subjects who did not receive or performed incomplete/inadequate IAP can be due to those women admitted in advanced labor or presenting with a precipitous one, in addition to the few cases in which it was omitted for misinterpreted/incorrect data on GBS status at delivery. In Central Italy a major proportion (> 90%) of individuals showing GBS-positive cultures received adequate treatment [ 20 ]. In the USA, the prevalence of mothers with an indication for IAP who received adequate treatment increased, from 73.8% between 1998 and 1999 to 85.1% between 2003 and 2004 [ 26 , 27 ]. Comparing the pandemic period (years 2020–2021) with the following one (2022), a lower frequency in the execution of vaginal-rectal swabs for GBS, as well as of adequate and complete IAP, were found in the first two years than in 2022 (Fig. 5a /b ). In fact, during the COVID-19 period, isolation, mask wearing, hand hygiene, and other infection control and preventive measures adopted to lessen the pandemic's effects resulted in a decrease in the access to various health facilities, including obstetric and perinatal care services. This reduction was attributed to the concern of getting sick perceived by people, as well as to the challenges in maintaining the support of other family members during the hospital stay [ 11 , 12 ]. Finally, we detected inequalities between the Italian women and the foreign ones due to the major number of swabs performed among the former and, although not statistically significant, higher colonization rates in the latter. Moreover, we reported an EOD prevalence of 7.69% among children of mothers carrying risk factors, and of 6.06‰ on the total number of newborns delivered during the 3-year investigation. In our study the clinical picture of the early form of disease was represented by sepsis. According to literature, respiratory signs were the initial most common typical symptoms, only preceded by poor feeding/regurgitation associated with hypotonia, frequently described in literature reports as well [ 28 ]. The other less common clinical manifestations identified were fever, jaundice, and septic shock, which are not typical of GBS, and which can occur in other bacterial infections. Mortality is estimated to be 2–5% in full-term children, and increases by 25% in preterm infants; nonetheless, in our sample (in which, however, no preterm babies were present) neither deaths nor meningitis were documented [ 29 , 30 ]. It is noteworthy that, as expected, none of the mothers’ patients received adequate IAP. This study further highlights how relevant could be to begin IAP as soon as possible, when a clinical indication is identified (positive GBS screening culture, previous child with GBS disease, bacteriuria documenting GBS in the current pregnancy, in addition to those women whose GBS status is unknown at labor onset and at least one of the risk factors pointed out by CDC) [ 8 ]. This is due to the beneficial effects of IAP, which are fully reached when it is started at least four hours before birth. Our results demonstrate that there is still a relevant number of women colonized with GBS at delivery who did not perform appropriate IAP, or even who is not recognized as GBS-positive by antenatal screening cultures. The current research underlines how crucial could be the definition of pregnant women's GBS colonization status, through vaginal and rectal swabs obtained between 35 and 37 weeks of gestation. Indeed, the identification and treatment of candidates for IAP are necessary, as moreover evidenced by the present study, also owing to the higher risk of developing EOD for neonates born to mothers without GBS screening and not receiving adequate and/or complete IAP. In order to stop and/or limit GBS infections, local public health organizations should support both microbiological surveillance and educational initiatives [ 31 , 32 ]. These interventions, actually, are able to reduce by 80% the risk of neonatal sepsis or meningitis, specifically early onset ones, i.e. those between birth and the completion of the 6th day of life [ 33 ]. Indeed, such strategies cannot be effective in the remaining 20% of early infections, as they are not linked to fetal contamination with the bacteria encountered during the passage through the vaginal canal at birth. They are, rather, dependent on infections contracted prior to the delivery, due to the ascending passage of germs to the fetus, especially in case of premature rupture of membranes. Furthermore, IAP is not active for late infections, i.e. those occurring between the 6th and the 89th day of life. In these cases, in fact, baby's infection relies on extrapartum factors, generally contamination of the mother while caring for the child, intra-hospital spread by other colonized patients or through breast milk [ 34 , 35 ]. Although the total number of cases of neonatal GBS infection is not reported to be overly high, as highlighted also in the present analysis, however it is clear that the prophylaxis measures adopted to date cannot be considered fully satisfactory. Pregnant woman screening, indeed, is not always easy to implement, as well as the administration of intrapartum antibiotics, which often does not follow in the clinical daily practice (as evidenced in our experience), the effective modalities established by CDC guidelines for the eradication of the bacterium. Clinicians, then, need to be careful and accurate in the correct adhesion to care protocols, also in consideration of the significant number of incomplete cultures performed and incorrect IAP administrations, as documented by the present analysis. In addition to the implementation and improvement of antibiotic prophylaxis, however, the search for alternative preventive tools, such as the production of an effective and safe vaccine administered to the mother, appears urgent and not postponable [ 36 – 38 ]. Nonetheless, its production has set many difficulties in the realization process. They are linked to the presence of at least 10 GBS strains showing a different capsular polysaccharide, which is the major virulence factor of the bacterium. Specifically, 6 of them (Ia, Ib, and II up to V) are the most frequently involved in invasive disease [ 37 ]. Finally, it is necessary both to establish the best administration time during pregnancy, and any potential harmful effects to the embryo and/or fetus [ 39 ]. The results of research are ongoing, pointing at promising perspectives in obtaining a vaccination able to prevent invasive GBS disease in the majority of cases [ 39 ]. Conclusions The present study revealed in our Department an increased prevalence of pregnant women screened for, and colonized by GBS, in the last decade. However, a lower frequency in the execution of vaginal-rectal swabs for GBS, as well as of adequate and complete IAP were found in the first two years of the study (2020–2021) than in 2022. Such data are in accordance with those observed during the pandemic period for other care settings (especially emergency care areas, as well as surgery and diagnostic services), where significant delays in diagnosis and treatment, and increase in mortality/morbidity rates due to the indirect effects of COVID-19 (reduction in the number of clinical checks, fear in the access to health facilities) have been described. Furthermore, inequalities in the number of swabs performed persist, compared to the past, between Italian and foreign women, highlighting an insufficient health support provided to migrant and at risk populations. IAP is the only prophylactic method currently available and effective against neonatal GBS infection. Although this is an easy procedure to implement, and actually our population of women subjected to screening and undergoing prophylaxis increased in the last years, however adherence and uniformity in the management protocols are still not optimal, as documented by the rates in which IAP was inadequate/incomplete or even omitted. Furthermore, we reported significant EOD prevalence rates among children of mothers carrying risk factors. Although the total number of neonatal GBS infections is not reported to be overly high, as documented also in the present analysis, however the prophylactic measures adopted to date cannot be considered fully satisfactory, and should therefore be improved. Better skills integration and obstetrical-neonatal collaboration, in addition to new effective preventive tools, like vaccines able to prevent invasive disease, may allow further reduction in morbidity and mortality rates related to GBS perinatal infection. Declarations Ethics approval and consent to participate The study was approved by the Mother and Child Department of the University of Palermo, ethics committee Palermo 1 (Palermo, Italy). All procedures performed in this report were in accordance with the ethical standards of the institutional and national research committee, and with the 1964 Helsinki declaration and its later amendments, or comparable ethical standards. Consent for publication Not applicable. Availability of data and materials The datasets used and analyzed during the current study are available from the corresponding author on reasonable request. Competing interests We declare that the first and last author of the manuscript, Gregorio Serra and Giovanni Corsello, have the role, within Italian Journal of Pediatrics, as Associate Editor and Editor-in-chief respectively. Funding No funding was granted for this research. Authors’ contributions GS drafted the manuscript and took care of the patients. LLS performed the statistical analysis and drafted the first version of the paper. MGio gathered the data related to pregnant women. MGiu revised the manuscript. PT reviewed the literature, made the database and analyzed the data. RV supervised the study and revised the paper. GC conceived the study, revised the manuscript and gave final approval of the version to be submitted. All authors red and approved the manuscript as submitted. Acknowledgements Not applicable. References World Health Organization. Group B Streptococcus Vaccine Development Technology Roadmap: Priority Activities for Development, Testing, Licensure and Global Availability of Group B Streptococcus Vaccines. World Health Organization: Geneva, Switzerland,; 2017. 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Epidemiology of Invasive Early-Onset and Late-Onset Group B Streptococcal Disease in the United States, 2006 to 2015: Multistate Laboratory and Population-Based Surveillance. JAMA Pediatr. 2019;173(3):224–33. Cascella M, Rajnik M, Aleem A, Dulebohn SC, Di Napoli R, Features. Evaluation, and Treatment of Coronavirus (COVID-19). 2023 Aug 18. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024. Jan–. Kotlar B, Gerson EM, Petrillo S, Langer A, Tiemeier H. The impact of the COVID-19 pandemic on maternal and perinatal health: a scoping review. Reprod Health. 2021;18(1):10. Cena L, Rota M, Calza S, Massardi B, Trainini A, Stefana A. Estimating the Impact of the COVID-19 Pandemic on Maternal and Perinatal Health Care Services in Italy: Results of a Self-Administered Survey. Front Public Health. 2021;9:701638. Linee Guida Nazionali Gravidanza fisiologica. (Aggiornamenti del 2011). Sistema nazionale per le linee guida (SNLG), Istituto superiore di sanità (ISS), Centro nazionale epidemiologia, sorveglianza e promozione della salute (CNESPS). https://www.salute.gov.it/imgs/C_17_pubblicazioni_1436_allegato.pdf . Puopolo KM, Lynfield R, Cummings JJ. Management of infants at risk for group B streptococcal disease. Pediatrics. 2019;144(2):e20191881. Prevention of Early-onset Neonatal Group B Streptococcal Disease. Green-top Guideline 36 BJOG. 2017;124(12):e280–305. Prevention of Group B Streptococcal Early-Onset Disease in Newborns. ACOG Committee Opinion, Number 797. Obstet Gynecol. 2020;135(2):e51–72. Schrag SJ, Verani JR. Intrapartum antibiotic prophylaxis for the prevention of perinatal group B streptococcal disease: experience in the United States and implications for a potential group B streptococcal vaccine. Vaccine. 2013;31(Suppl 4):D20–6. Zhu Y, Lin XZ. Updates in prevention policies of early-onset group B streptococcal infection in newborns. Pediatr Neonatol. 2021;62(5):465–75. Puccio G, Cajozzo C, Canduscio LA, Cino L, Romano A, Schimmenti MG, Giuffrè M, Corsello G. Epidemiology of Toxoplasma and CMV serology and of GBS colonization in pregnancy and neonatal outcome in a Sicilian population. Ital J Pediatr. 2014;40:23. Berardi A, Di Fazzio G, Gavioli S, Di Grande E, Groppi A, Papa I, Piccinini G, Simoni A, Tridapalli E, Volta A, Facchinetti F, Ferrari F, GBS Prevention Working Group. Emilia-Romagna. Universal antenatal screening for group B streptococcus in Emilia-Romagna. J Med Screen. 2011;18(2):60–4. Infezioni neonatali precoci e tardive da streptococco di gruppo B in Italia. Edited by Creti R. Roma: Istituto Superiore di Sanità. 2011. Rapporti ISTISAN 11/7. Prevalence of maternal. colonisation with group B streptococcus: a systematic review and meta-analysis. Lancet Infect Dis. 2016;16(9):1076–84. Kwatra G, Cunnington MC, Merrall E, Adrian PV, Ip M, Klugman KP, Tam WH, Madhi SA, Berkley JA, Lowe BS, Mwangi I, Williams T, Bauni E, Mwarumba S, et al. Bacteremia among children admitted to a rural hospital in Kenya. N Engl J Med. 2005;352(1):39–47. Chaudhary M, Rench MA, Baker CJ, Singh P, Hans C, Edwards MS. Group B Streptococcal Colonization Among Pregnant Women in Delhi, India. Pediatr Infect Dis J. 2017;36(7):665–9. Costa NS, Rio-Tinto A, Pinto IBF, Dos Santos Silva Alvim DC, de Assis Rocha A, Oliveira LMA, Botelho ACN, Fracalanzza SEL, Teixeira LM, Rezende-Filho J, Marinho PS, Amim Júnior J, Taylor S, Thomas S, Pinto TCA. Changes in Group B Streptococcus Colonization among Pregnant Women before and after the Onset of the COVID-19 Pandemic in Brazil. Pathogens. 2022;11(10):1104. Van Dyke MK, Phares CR, Lynfield R, Thomas AR, Arnold KE, Craig AS, Mohle-Boetani J, Gershman K, Schaffner W, Petit S, Zansky SM, Morin CA, Spina NL, Wymore K, Harrison LH, Shutt KA, Bareta J, Bulens SN, Zell ER, Schuchat A, Schrag SJ. Evaluation of universal antenatal screening for group B streptococcus. N Engl J Med. 2009;360(25):2626–36. Schrag SJ, Zell ER, Lynfield R, Roome A, Arnold KE, Craig AS, Harrison LH, Reingold A, Stefonek K, Smith G, Gamble M, Schuchat A. Active Bacterial Core Surveillance Team. A population-based comparison of strategies to prevent early-onset group B streptococcal disease in neonates. N Engl J Med. 2002;347(4):233–9. Edmond KM, Kortsalioudaki C, Scott S, Schrag SJ, Zaidi AK, Cousens S, Heath PT. Group B streptococcal disease in infants aged younger than 3 months: systematic review and meta-analysis. Lancet. 2012;379:547–56. Baker CJ. Early onset group B streptococcal disease. J Pediatr. 1978;93(1):124–5. Piro E, Serra G, Schierz IAM, Giuffrè M, Corsello G. Fetal growth restriction: a growth pattern with fetal, neonatal and long-term consequences. Euromediterranean Biomedical J. 2019;14(09):038–44. Serra G, Giuffrè M, Piro E, Corsello G. The social role of pediatrics in the past and present times. Ital J Pediatr. 2021;47(1):239. Serra G, Miceli V, Albano S, Corsello G. Perinatal and newborn care in a two years retrospective study in a first level peripheral hospital in Sicily (Italy). Ital J Pediatr. 2019;45(1):152. Boyer KM, Gadzala CA, Kelly PD, Gotoff SP. Selective intrapartum chemoprophylaxis of neonatal group B streptococcal early-onset disease. III. Interruption of mother-to-infant transmission. J Infect Dis. 1983;148:810–6. Anthony BF, Okada DM, Hobel CJ. Epidemiology of the group B streptococcus: maternal and nosocomial sources for infant acquisitions. J Pediatr. 1979;95(3):431–6. Godambe S, Shah PS, Shah V. Breast milk as a source of late onset neonatal sepsis. Pediatr Infect Dis J. 2005;24(4):381–2. Trijbels-Smeulders MA, Kollée LA, Adriaanse AH, Kimpen JL, Gerards LJ. Neonatal group B streptococcal infection: incidence and strategies for prevention in Europe. Pediatr Infect Dis J. 2004;23(2):172–3. Johri AK, Paoletti LC, Glaser P, Dua M, Sharma PK, Grandi G, Rappuoli R. Group B Streptococcus: global incidence and vaccine development. Nat Rev Microbiol. 2006;4(12):932–42. Jordan HT, Farley MM, Craig A, Mohle-Boetani J, Harrison LH, Petit S, Lynfield R, Thomas A, Zansky S, Gershman K, Albanese BA, Schaffner W, Schrag SJ. Active Bacterial Core Surveillance (ABCs)/Emerging Infections Program Network, CDC. Revisiting the need for vaccine prevention of late-onset neonatal group B streptococcal disease: a multistate, population-based analysis. Pediatr Infect Dis J. 2008;27(12):1057–64. Madhi SA, Anderson AS, Absalon J, Radley D, Simon R, Jongihlati B, Strehlau R, van Niekerk AM, Izu A, Naidoo N, Kwatra G, Ramsamy Y, Said M, Jones S, Jose L, Fairlie L, Barnabas SL, Newton R, Munson S, Jefferies Z, Pavliakova D, de Silmon NC, Gomme E, Perez JL, Scott DA, Gruber WC, Jansen KU. Potential for Maternally Administered Vaccine for Infant Group B Streptococcus. N Engl J Med. 2023;389(3):215–27. Cite Share Download PDF Status: Published Journal Publication published 13 Sep, 2024 Read the published version in Italian Journal of Pediatrics → Version 1 posted Editorial decision: Major revision 16 Jun, 2024 Reviewers agreed at journal 18 May, 2024 Reviewers invited by journal 18 May, 2024 First submitted to journal 25 Apr, 2024 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-4189394","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":303984812,"identity":"1726998a-6a9f-41dc-ac5c-8ea67cb82e31","order_by":0,"name":"Gregorio 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Palermo","correspondingAuthor":false,"prefix":"","firstName":"Lucia","middleName":"Lo","lastName":"Scalzo","suffix":""},{"id":303984814,"identity":"937a5872-7ae8-4e67-8853-f9100ee3deb1","order_by":2,"name":"Maria Giordano","email":"","orcid":"","institution":"University of Palermo: Universita degli Studi di Palermo","correspondingAuthor":false,"prefix":"","firstName":"Maria","middleName":"","lastName":"Giordano","suffix":""},{"id":303984815,"identity":"77927548-de58-45ee-9abc-7a538b2819c3","order_by":3,"name":"Mario Giuffrè","email":"","orcid":"","institution":"University of Palermo: Universita degli Studi di Palermo","correspondingAuthor":false,"prefix":"","firstName":"Mario","middleName":"","lastName":"Giuffrè","suffix":""},{"id":303984816,"identity":"5d68015e-4433-4992-9944-642d31e691e9","order_by":4,"name":"Pietro Trupiano","email":"","orcid":"","institution":"University of Palermo: Universita degli Studi di Palermo","correspondingAuthor":false,"prefix":"","firstName":"Pietro","middleName":"","lastName":"Trupiano","suffix":""},{"id":303984817,"identity":"699f8365-a969-455e-96d8-421034adb942","order_by":5,"name":"Renato Venezia","email":"","orcid":"","institution":"University of Palermo: Universita degli Studi di Palermo","correspondingAuthor":false,"prefix":"","firstName":"Renato","middleName":"","lastName":"Venezia","suffix":""},{"id":303984818,"identity":"7413f443-8ed3-4dfb-8aa5-02aaef610db1","order_by":6,"name":"Giovanni Corsello","email":"","orcid":"","institution":"University of Palermo: Universita degli Studi di Palermo","correspondingAuthor":false,"prefix":"","firstName":"Giovanni","middleName":"","lastName":"Corsello","suffix":""}],"badges":[],"createdAt":"2024-03-29 18:46:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4189394/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4189394/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13052-024-01738-2","type":"published","date":"2024-09-13T15:57:38+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":57721129,"identity":"a62d71ca-21cd-4062-a696-f571cadce1cb","added_by":"auto","created_at":"2024-06-04 18:56:13","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":44339,"visible":true,"origin":"","legend":"\u003cp\u003eNumber of swabs performed during the study period (expressed in absolute values and percentages) \u003cstrong\u003e(a)\u003c/strong\u003e, and divided by year \u003cstrong\u003e(b)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"figure1GBS300dpi.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/7f0669296cec35aae4653d6d.jpg"},{"id":57721137,"identity":"04f589bd-2762-4f93-9db1-a4690b57e832","added_by":"auto","created_at":"2024-06-04 18:56:14","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":44767,"visible":true,"origin":"","legend":"\u003cp\u003eResults of the performed swabs \u003cstrong\u003e(a)\u003c/strong\u003e, and number of positive ones divided by year \u003cstrong\u003e(b)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure2GBS300dpi.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/57e07627d191c1cd41e669fc.jpg"},{"id":57722338,"identity":"b33d0357-8258-48ba-8854-33a0207f7b5c","added_by":"auto","created_at":"2024-06-04 19:04:14","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":47171,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eIntrapartum\u003c/em\u003e antibiotic prophylaxis administration profiles in our population of pregnant women\u003c/p\u003e","description":"","filename":"Figure3GBS300dpi.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/0f89ca08581442b1894e8a0b.jpg"},{"id":57721130,"identity":"bd5b48c4-8d11-432f-9bc4-8fb446604967","added_by":"auto","created_at":"2024-06-04 18:56:13","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":47123,"visible":true,"origin":"","legend":"\u003cp\u003eOverall number and rates of pregnant women with and without indications for IAP administration \u003cstrong\u003e(a)\u003c/strong\u003e, and IAP profiles in those with \u003cem\u003eintrapartum\u003c/em\u003e risk factors \u003cstrong\u003e(b)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Fig4GBS300dpi.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/31fa87ff6300b647808dc72d.jpg"},{"id":57721132,"identity":"1972be90-ee26-46c4-9c62-88285fb1ea0f","added_by":"auto","created_at":"2024-06-04 18:56:13","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":60078,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of swabs performed \u003cstrong\u003e(a)\u003c/strong\u003e, IAP administration \u003cstrong\u003e(b)\u003c/strong\u003e and maternal GBS colonization \u003cstrong\u003e(c)\u003c/strong\u003e rates between the pandemic period (years 2020-2021) and the following one (year 2022)\u003c/p\u003e","description":"","filename":"Figure5GBS300dpi.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/635f9c96904d52270f4be81b.jpg"},{"id":57721133,"identity":"3bd6ad21-db44-4ef3-898f-a43406bbb393","added_by":"auto","created_at":"2024-06-04 18:56:13","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":49265,"visible":true,"origin":"","legend":"\u003cp\u003eOverall number and rates of neonates with and without EOD born to women with risk factors \u003cstrong\u003e(a)\u003c/strong\u003e, and IAP profiles in the mothers of EOD newborns \u003cstrong\u003e(b)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure6GBS.300dpi.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/fd6aa1d3f0f648ee4fa4eb3a.jpg"},{"id":57721135,"identity":"f2ca5023-4f7f-42de-9404-189908b422b6","added_by":"auto","created_at":"2024-06-04 18:56:14","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":46233,"visible":true,"origin":"","legend":"\u003cp\u003eClinical manifestations of EOD neonates\u003c/p\u003e","description":"","filename":"Figure7GBS300dpi.pptx.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/feba806e9b339e54e33e7f78.jpg"},{"id":57722337,"identity":"1cc84704-bb5c-421d-abd5-f6d5883ec5f3","added_by":"auto","created_at":"2024-06-04 19:04:13","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":55699,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of GBS screening among the current study and those previously reported in our Hospital and in Central Italy \u003cstrong\u003e(a)\u003c/strong\u003e, and of maternal GBS colonization between present analysis and that conducted by Puccio et al. in 2012 in our Department \u003cstrong\u003e(b)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure8GBS300dpi.pptx.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/cb8750c00e57258ca134918a.jpg"},{"id":57721134,"identity":"e2ac9daf-74e0-4f66-90d7-9146d7bd9a77","added_by":"auto","created_at":"2024-06-04 18:56:13","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":56749,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of maternal GBS colonization rates among current study and those reported in other regions worldwide\u003c/p\u003e","description":"","filename":"Figure9GBS300dpi.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/c73e89e2d180f9592bd831cd.jpg"},{"id":64619509,"identity":"91f4a4e0-8649-4c63-bd0c-ca979327e360","added_by":"auto","created_at":"2024-09-16 16:15:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":997933,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4189394/v1/39104adc-5eea-49d9-ad49-0e8d5c0f61cd.pdf"}],"financialInterests":"","formattedTitle":"Group B streptococcus colonization in pregnancy and neonatal outcomes: a three-year monocentric retrospective study during and after the COVID-19 pandemic","fulltext":[{"header":"Background","content":"\u003cp\u003eGroup B \u003cem\u003eStreptococcus\u003c/em\u003e (GBS), also known as \u003cem\u003eStreptococcus agalactiae\u003c/em\u003e for its causative role in bovine mastitis, is present in the genitourinary and gastrointestinal tracts of pregnant women. Maternal GBS colonization rates vary worldwide from 10 to 40%, with mean prevalence of 18% [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The infection may cause asymptomatic bacteriuria, as well as urinary tract infections like pyelonephritis, and also chorioamnionitis, \u003cem\u003epostpartum\u003c/em\u003e endometritis, pneumonia and puerperal sepsis. It may also be responsible for miscarriage, as well as preterm birth and premature rupture of membranes (PROM) [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In the newborn, GBS infection has bimodal distribution, giving rise to both early (EOD) and late onset diseases (LOD). EOD is generally acquired by vertical transmission and occurs within 24 hours after birth in the 60\u0026ndash;80% of cases, within 72 hours in the 90%, but can manifest at any time during the first week of life. The most common clinical pictures of EOD include sepsis, pneumonia and meningitis. LOD, conversely, may be observed between 7 and 90 days of life, and the association with maternal colonization is not as strong as for EOD [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The Centers for Disease Control and Prevention (CDC) recommends for pregnant women, between 35 and 37 weeks of gestation, universal vaginal-rectal screening for GBS colonization [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Furthermore, \u003cem\u003eintrapartum\u003c/em\u003e antibiotic prophylaxis (IAP) administrated\u0026thinsp;\u0026ge;\u0026thinsp;4 h before delivery is the only currently available and highly effective method against GBS neonatal infections, resulting in a reduction in the incidence of EOD of more than 80%, from 1.8 newborns per 1,000 live births in the 1990s to 0.23 newborns per 1,000 live births in 2015, although not being able to limit the impact of LOD [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, more than 6.9\u0026nbsp;million people died worldwide due to SARS-CoV-2 infection [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In Italy, it has been associated with significant clinical and psychological effects, also in pregnant women. Indeed, the infection control and the preventive measures (social distancing, mask wearing, hand hygiene and quarantine) implemented to mitigate the effects of the pandemic, led to the reduction in the access to many health facilities and services, including the obstetric and perinatal ones. Such decrease was linked both to the difficulties encountered by people in keeping the support from other family members within the hospital, and to the fear of contracting the infection [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The purpose of the present study was to retrospectively evaluate the prevalence rates of maternal vaginal-rectal GBS colonization, as well as use and effects of IAP in the newborn, in a population of pregnant women during (years 2020\u0026ndash;2021) and after (year 2022) the COVID-19 pandemic, also with the aim to establish possible epidemiological and clinical differences in the two subjects\u0026rsquo; groups.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe retrospectively analyzed the clinical data of pregnant women admitted to, and delivering, at the Gynaecology and Obstetrics Unit, Department of Sciences for Health Promotion and Mother and Child Care, of the University Hospital of Palermo, Italy, from 01.01.2020 to 31.12.2022. For each of them, we recorded the pertinent socio-demographic information, and the clinical data related to pregnancy, delivery and \u003cem\u003eperipartum\u003c/em\u003e, and specifically:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eage at delivery;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003enationality;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eresidence;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eoccupation;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eexecution and status of vaginal and rectal swab test for GBS detection between 35 and 37 weeks of gestation;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003etype of delivery (i.e., vaginal, elective or emergency cesarean section);\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003epremature rupture of membranes (PROM, \u0026ge;\u0026thinsp;18 h before delivery);\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eeventual IAP.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eWe considered the results of vaginal and rectal swabs for GBS, performed between weeks 35\u003csup\u003e+\u0026thinsp;0\u003c/sup\u003e and 37\u003csup\u003e+\u0026thinsp;0\u003c/sup\u003e of gestation. This procedure is usually performed routinely in our Hospital in such time window, according to the indications of the CDC [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Specifically, IAP was recommended in women with a positive GBS screening culture (excluding those undergoing cesarean delivery with intact amniotic membranes before labor onset), a previous child with GBS disease, bacteriuria documenting GBS in the current pregnancy, and in those with unknown GBS status at labor onset and at least one of the following risk factors: delivery at \u0026lt;\u0026thinsp;37 weeks\u0026rsquo; gestation, amniotic membranes rupture\u0026thinsp;\u0026ge;\u0026thinsp;18 hours and/or \u003cem\u003eintrapartum\u003c/em\u003e temperature\u0026thinsp;\u0026ge;\u0026thinsp;38.0\u0026deg;C [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. However, many variations of practice, based on the individual gynecologist and/or on mother\u0026rsquo;s compliance, have been observed during the study period in our sample population. Ampicillin was the first-line drug used, and it was administered intravenously (IV) at the dose of 2 g, followed by 1 g IV every 4 h until delivery. Cefazolin was the option chosen for women allergic to penicillin but not at high risk for anaphylaxis, while clindamycin or vancomycin have been used for high risk of anaphylaxis to penicillin, according to guidelines [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. IAP was considered adequate and complete when administered\u0026thinsp;\u0026ge;\u0026thinsp;4 h before delivery [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. We focused on the rate of patients undergoing GBS screening, and on those with positive GBS screening tests. We also evaluated the indications for IAP, as well as the modality of IAP execution (if either adequate/complete or not).\u003c/p\u003e \u003cp\u003eThe neonatal outcome was investigated in all cases at risk and, in particular, we analyzed for each newborn:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003esex;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003egestational age;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eApgar scores at 1 and 5 minutes;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eweight, length and occipitofrontal circumference at birth, and respective percentiles;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003erespiratory, metabolic and systemic disturbances; neurological manifestations and/or feeding problems;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eblood cell count; C reactive protein (CRP) and/or procalcitonin (PCT) values; blood culture results;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eeventual admission to neonatal intensive care unit (NICU);\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eeventual intravenous antibiotic therapy, its duration, and type of drugs used.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eThe data observed during the pandemic (years 2020\u0026ndash;2021) were compared with those recorded in the following period (year 2022).\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eWe used R version 4.0.4 (R Foundation for Statistical Computing, Vienna, Austria) for data analysis. Simple descriptive statistics were expressed as frequency and percentage for categorical variables, mean and standard deviation for continuous variables. Paired-samples t-test was used to compare data on the vaginal-rectal GBS colonization rate, as well as use of IAP and its effects on neonatal outcomes during (years 2020\u0026ndash;2021) and after (year 2022) the COVID-19 pandemic.\u003c/p\u003e \u003cp\u003eA \u003cem\u003ep\u003c/em\u003e value lower than 0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e \u003cb\u003eSocio-demographic information, and clinical data related to pregnancy, delivery and\u003c/b\u003e \u003cb\u003eperipartum\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe total number of deliveries observed during the study period was 2315, including 35 twin births (all bigeminal). The medical records were not available for 206 mothers, and therefore the present analysis involved 2109 pregnant women, in addition to their 2144 newborns. Evaluated by year, the total number of delivering women was as follows: 660 in 2020, 757 in 2021, and 692 in 2022. There were 141 preterm (\u0026lt;\u0026thinsp;37 weeks of gestational age) deliveries, while the other 1968 were full-term ones. In the population under investigation, the average age was 30.42\u0026thinsp;\u0026plusmn;\u0026thinsp;6 years, ranging between 15 and 52. Foreign mothers, defined as those who were not born in Italy, were the 12.94%. The most frequent countries of birth were Bangladesh (40.2%), Nigeria (15.01%), Morocco (7.69%), Romania (7.47%) and Tunisia (5.1%). The 69.41% of participants were resident in urban areas, while 30.59% came from rural ones. In regard with mothers\u0026rsquo; occupation, 73.82% were housewives, 14.22% employees, 10.38% freelance professionals and 1.57% craftswomen/tradeswomen. In our sample, 1004 women (47.61%) had vaginal deliveries, while 650 (30.82%) and 455 (21.57%) underwent elective and emergency cesarean sections, respectively. 779 participants (36.94%) were primiparous.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003ePrevalence rates of maternal GBS colonization and use of IAP\u003c/h2\u003e \u003cp\u003eThe vaginal-rectal swab for GBS was performed in 1559 (73.92%) individuals. More precisely, 512 were carried out in 2020, 560 in 2021 and 487 in 2022 (Fig.\u0026nbsp;1a\u003cb\u003e/b\u003c/b\u003e).\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 1a/b\u003c/b\u003e. Number of swabs performed during the study period (expressed in absolute values and percentages) \u003cb\u003e(a)\u003c/b\u003e, and divided by year \u003cb\u003e(b)\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe test resulted positive in 178 cases overall (11.42% of those undergoing the screening): 56 were those in 2020, 66 in 2021, and 56 in 2022 (Fig.\u0026nbsp;2a\u003cb\u003e/b\u003c/b\u003e).\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 2a/b\u003c/b\u003e. Results of the performed swabs \u003cb\u003e(a)\u003c/b\u003e, and number of positive ones divided by year \u003cb\u003e(b)\u003c/b\u003e\u003c/p\u003e \u003cp\u003eAmong GBS-positive patients, 41 (23.03%) received complete IAP, while to 20 (11.24%) an incomplete IAP was administered. 48 women (26.97%) did not receive IAP, due to cesarean sections performed before the onset of labor and with intact amniotic membranes; 69 subjects (38.76%), conversely, did not undergo IAP despite the presence of one or more clinical indications (Fig.\u0026nbsp;3).\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 3\u003c/b\u003e. \u003cem\u003eIntrapartum\u003c/em\u003e antibiotic prophylaxis administration profiles in our population of pregnant women\u003c/p\u003e \u003cp\u003eOf the 550 (26.08%) pregnant women with unknown GBS colonization status, 120 (21.82%) had \u003cem\u003eintrapartum\u003c/em\u003e risk factors. In this group, preterm delivery (\u0026lt;\u0026thinsp;37 weeks of gestation) was the only risk condition in 65 patients (11.82%), PROM\u0026thinsp;\u0026ge;\u0026thinsp;18 hours in 43 (7.82%), while 12 (2.18%) of them had both risk factors (preterm delivery and PROM\u0026thinsp;\u0026ge;\u0026thinsp;18 hours). No women presented with fever and/or other signs of chorioamnionitis. Considering only the individuals with \u003cem\u003eintrapartum\u003c/em\u003e risk factors, 23 (19.17%) received complete IAP, the prophylaxis was incomplete in 3 (2.5%) cases, and for 94 (78.33%) it was not administered. Amongst our overall sample, 298 women had an indication for IAP (Fig.\u0026nbsp;4a), and 64 (21.48%) received adequate treatment; for 23 (7.72%) it was inadequate/incomplete, while 211 (70.8%) did not receive IAP (Fig.\u0026nbsp;4b). Most cases where the prophylaxis was indicated, but in which it was not performed or was inadequate/incomplete, were represented by pregnant women admitted to hospital in advanced labor or presenting with precipitous delivery. In a few subjects IAP was simply omitted, probably for misinterpreted/incorrect data on GBS swabs at the time of birth.\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 4a/b\u003c/b\u003e. Overall number and rates of pregnant women with and without indications for IAP administration \u003cb\u003e(a)\u003c/b\u003e, and IAP profiles in those with \u003cem\u003eintrapartum\u003c/em\u003e risk factors \u003cb\u003e(b)\u003c/b\u003e\u003c/p\u003e \u003cp\u003eComparing the Italian mothers with the foreign ones, a higher incidence (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001\u003cem\u003e)\u003c/em\u003e in the execution of vaginal-rectal swabs for GBS was found in the period under investigation among the former (75.49% \u003cem\u003evs\u003c/em\u003e 63.37%), as well as a greater number (although not statistically significant, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.72) of adequate and complete IAP (21.86% \u003cem\u003evs\u003c/em\u003e 19.61%). Conversely, the rate of positive GBS swabs was significantly higher among the foreign mothers (10.46% in the group of Italian women vs 19.08% in the latter, p\u0026thinsp;=\u0026thinsp;0.0008). Comparing the pandemic period (years 2020\u0026ndash;2021) with the following one (year 2022), a lower incidence (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009\u003cem\u003e)\u003c/em\u003e in the execution of vaginal-rectal swabs for GBS was found in the first two years (70.38% during \u003cem\u003evs\u003c/em\u003e 75.65% after the COVID-19 pandemic; \u003cb\u003eFig.\u0026nbsp;5a\u003c/b\u003e), while a greater number (although not statistically significant, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.12) of adequate and complete IAP conducted in 2022, than in the previous biennium (26.36 \u003cem\u003evs\u003c/em\u003e 18.62%; \u003cb\u003eFig.\u0026nbsp;5b\u003c/b\u003e). Finally, the comparison between the periods during and after COVID-19 revealed a mildly lower (without statistical significance, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.94) GBS colonization rate during the pandemic than the following year (11.38% \u003cem\u003evs\u003c/em\u003e 11.5%; \u003cb\u003eFig.\u0026nbsp;5c\u003c/b\u003e).\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 5a/b/c\u003c/b\u003e. Comparison of swabs performed \u003cb\u003e(a)\u003c/b\u003e, IAP administration \u003cb\u003e(b)\u003c/b\u003e and maternal GBS colonization \u003cb\u003e(c)\u003c/b\u003e rates between the pandemic period (years 2020\u0026ndash;2021) and the following one (year 2022)\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eEffects of maternal GBS colonization in the newborn\u003c/h2\u003e \u003cp\u003eDuring the study period, 13 neonates with EOD, out of 179 (7.3%) born to mothers with risk factors (including overall those showing positive, negative, and unknown GBS status, i.e. 60, 11 and 108 respectively), were observed (the global prevalence on the total of babies delivered in the period under investigation was 6.06\u0026permil;) (Fig.\u0026nbsp;6a). Among them, 9 were male and 4 female. Mean gestational age was 39\u003csup\u003e+\u0026thinsp;4\u003c/sup\u003e weeks. All babies had normal Apgar scores (\u0026gt;\u0026thinsp;7) at 1 and 5 minutes. The average birth weight was 3249\u0026thinsp;\u0026plusmn;\u0026thinsp;482 g, length 49.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7 cm, and occipitofrontal circumference 34.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5 cm.\u003c/p\u003e \u003cp\u003e2 of them were small for gestational age (SGA), while 11 were appropriate for gestational age (AGA). 3 among these patients\u0026rsquo; mothers performed incomplete IAP, while the others did not receive IAP (Fig.\u0026nbsp;6b).\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 6a/b.\u003c/b\u003e Overall number and rates of neonates with and without EOD born to women with risk factors \u003cb\u003e(a)\u003c/b\u003e, and IAP profiles in the mothers of EOD newborns \u003cb\u003e(b)\u003c/b\u003e\u003c/p\u003e \u003cp\u003eClinical manifestations included septic shock (1), jaundice (1), respiratory distress (4), feeding difficulties/regurgitation associated with hypotonia (6), while hyperpyrexia was present in 1 case \u003cb\u003e(Fig.\u0026nbsp;7)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 7\u003c/b\u003e. Clinical manifestations of EOD neonates\u003c/p\u003e \u003cp\u003eIncreased inflammation indices (CRP and/or PCT) were detected in all newborns. Blood cultures were carried out in all subjects before the start of antibiotic therapy, and resulted negative in all cases. 4 subjects required hospitalization in the NICU, while in 9 cases the admission to the Neonatal Pathology Unit (sub-intensive care setting) was necessary. The patients were hospitalized for an average of 11\u0026thinsp;\u0026plusmn;\u0026thinsp;3 days. The mean duration of antibiotic therapy was 7\u0026thinsp;\u0026plusmn;\u0026thinsp;3 days. Empiric therapy with ampicillin (100 mg/kg/dose every 12 hours) and gentamicin (4 mg/kg/dose every 24 hours) was promptly started in all neonates. The antimicrobial treatment was continued until clinical symptoms disappeared, as well as complete blood counts, inflammation indices, and blood culture tests gave normal/negative results. There was no evidence of meningitis in any case, and no deaths were observed. Comparing the pandemic period (years 2020\u0026ndash;2021) with the following one (year 2022), a higher rate (not statistically significant, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.53) of EOD was found in the first two years of the study (8.06% \u003cem\u003evs\u003c/em\u003e 5.45%).\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eGroup B Streptococcus is a major cause of invasive infections in neonates, with the colonization of the vaginal-rectal tract of pregnant women being the main transmission source. Our data provide updated insights about the prevalence of vaginal-rectal GBS colonization in pregnancy. In addition, the present study shows the rates of adhesion to GBS screening and to IAP in a cohort of pregnant women referring to a II level University Hospital in the city of Palermo, Italy. In our sample, the prevalence of subjects screened for GBS out of the total addressed to our Mother and Child Department was 73.92%; complete vaginal\u0026ndash;rectal screening for GBS was conducted in all cases. Such data were higher than those of a previous retrospective study carried out in our Hospital in 2012, and also than the rates recorded by Berardi A. et al. in 2011 in Central Italy, which were 66.03% and 67.9% respectively \u003cb\u003e(Fig.\u0026nbsp;8a)\u003c/b\u003e [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. According with CDC and the Italian Obstetrics Society guidelines, the execution of vaginal\u0026ndash;rectal cultures for GBS is recommended between 35 and 37 weeks of gestation, and such indications were those followed also in the present study [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In our population vaginal and rectal swabs were positive for GBS in the 10.42% of cases; this value is at the lower range of the national average, which is between 10 and 20% [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Comparing the current analysis with that carried out in 2012 in our Hospital, an increased prevalence of GBS colonization in our population has been observed in the last few years (from 7.98\u0026ndash;11.42%) \u003cb\u003e(Fig.\u0026nbsp;8b)\u003c/b\u003e [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 8a/b\u003c/b\u003e. Comparison of GBS screening among the current study and those previously reported in our Hospital and in Central Italy \u003cb\u003e(a)\u003c/b\u003e, and of maternal GBS colonization between present analysis and that conducted by Puccio et al. in 2012 in our Department \u003cb\u003e(b)\u003c/b\u003e\u003c/p\u003e \u003cp\u003eWorldwide, frequencies of maternal GBS carriers have been reported to range from 14 to 30% in high-income countries (mildly higher than the present survey), to be around 19% in the Sub-Saharan region, and 12\u0026ndash;15% in India and Pakistan (Fig.\u0026nbsp;9) [\u003cspan additionalcitationids=\"CR23\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Differences in the detected rate of vaginal-rectal GBS colonization may reflect the different demographic characteristics of the populations under investigation. Actually, GBS incidence rates can vary, either according to geographical region or time period [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Indeed, when comparing COVID-19 with the post-pandemic \u003cem\u003escenario\u003c/em\u003e, we detected a mild decrease in GBS maternal colonization during the years 2020\u0026ndash;2021 (11.38% \u003cem\u003evs\u003c/em\u003e 11.5%).\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 9\u003c/b\u003e. Comparison of maternal GBS colonization rates among current study and those reported in other regions worldwide\u003c/p\u003e \u003cp\u003eAmongst our overall sample, only 21.48% women received adequate IAP in presence of clinical indications (positive GBS screening culture or \u003cem\u003eintrapartum\u003c/em\u003e risk factors). The consequent higher rate of subjects who did not receive or performed incomplete/inadequate IAP can be due to those women admitted in advanced labor or presenting with a precipitous one, in addition to the few cases in which it was omitted for misinterpreted/incorrect data on GBS status at delivery. In Central Italy a major proportion (\u0026gt;\u0026thinsp;90%) of individuals showing GBS-positive cultures received adequate treatment [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In the USA, the prevalence of mothers with an indication for IAP who received adequate treatment increased, from 73.8% between 1998 and 1999 to 85.1% between 2003 and 2004 [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Comparing the pandemic period (years 2020\u0026ndash;2021) with the following one (2022), a lower frequency in the execution of vaginal-rectal swabs for GBS, as well as of adequate and complete IAP, were found in the first two years than in 2022 (Fig.\u0026nbsp;5a\u003cb\u003e/b\u003c/b\u003e). In fact, during the COVID-19 period, isolation, mask wearing, hand hygiene, and other infection control and preventive measures adopted to lessen the pandemic's effects resulted in a decrease in the access to various health facilities, including obstetric and perinatal care services. This reduction was attributed to the concern of getting sick perceived by people, as well as to the challenges in maintaining the support of other family members during the hospital stay [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Finally, we detected inequalities between the Italian women and the foreign ones due to the major number of swabs performed among the former and, although not statistically significant, higher colonization rates in the latter.\u003c/p\u003e \u003cp\u003eMoreover, we reported an EOD prevalence of 7.69% among children of mothers carrying risk factors, and of 6.06\u0026permil; on the total number of newborns delivered during the 3-year investigation. In our study the clinical picture of the early form of disease was represented by sepsis. According to literature, respiratory signs were the initial most common typical symptoms, only preceded by poor feeding/regurgitation associated with hypotonia, frequently described in literature reports as well [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The other less common clinical manifestations identified were fever, jaundice, and septic shock, which are not typical of GBS, and which can occur in other bacterial infections. Mortality is estimated to be 2\u0026ndash;5% in full-term children, and increases by 25% in preterm infants; nonetheless, in our sample (in which, however, no preterm babies were present) neither deaths nor meningitis were documented [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. It is noteworthy that, as expected, none of the mothers\u0026rsquo; patients received adequate IAP.\u003c/p\u003e \u003cp\u003eThis study further highlights how relevant could be to begin IAP as soon as possible, when a clinical indication is identified (positive GBS screening culture, previous child with GBS disease, bacteriuria documenting GBS in the current pregnancy, in addition to those women whose GBS status is unknown at labor onset and at least one of the risk factors pointed out by CDC) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. This is due to the beneficial effects of IAP, which are fully reached when it is started at least four hours before birth. Our results demonstrate that there is still a relevant number of women colonized with GBS at delivery who did not perform appropriate IAP, or even who is not recognized as GBS-positive by antenatal screening cultures. The current research underlines how crucial could be the definition of pregnant women's GBS colonization status, through vaginal and rectal swabs obtained between 35 and 37 weeks of gestation. Indeed, the identification and treatment of candidates for IAP are necessary, as moreover evidenced by the present study, also owing to the higher risk of developing EOD for neonates born to mothers without GBS screening and not receiving adequate and/or complete IAP.\u003c/p\u003e \u003cp\u003eIn order to stop and/or limit GBS infections, local public health organizations should support both microbiological surveillance and educational initiatives [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. These interventions, actually, are able to reduce by 80% the risk of neonatal sepsis or meningitis, specifically early onset ones, i.e. those between birth and the completion of the 6th day of life [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Indeed, such strategies cannot be effective in the remaining 20% of early infections, as they are not linked to fetal contamination with the bacteria encountered during the passage through the vaginal canal at birth. They are, rather, dependent on infections contracted prior to the delivery, due to the ascending passage of germs to the fetus, especially in case of premature rupture of membranes. Furthermore, IAP is not active for late infections, i.e. those occurring between the 6th and the 89th day of life. In these cases, in fact, baby's infection relies on \u003cem\u003eextrapartum\u003c/em\u003e factors, generally contamination of the mother while caring for the child, intra-hospital spread by other colonized patients or through breast milk [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Although the total number of cases of neonatal GBS infection is not reported to be overly high, as highlighted also in the present analysis, however it is clear that the prophylaxis measures adopted to date cannot be considered fully satisfactory. Pregnant woman screening, indeed, is not always easy to implement, as well as the administration of \u003cem\u003eintrapartum\u003c/em\u003e antibiotics, which often does not follow in the clinical daily practice (as evidenced in our experience), the effective modalities established by CDC guidelines for the eradication of the bacterium. Clinicians, then, need to be careful and accurate in the correct adhesion to care protocols, also in consideration of the significant number of incomplete cultures performed and incorrect IAP administrations, as documented by the present analysis. In addition to the implementation and improvement of antibiotic prophylaxis, however, the search for alternative preventive tools, such as the production of an effective and safe vaccine administered to the mother, appears urgent and not postponable [\u003cspan additionalcitationids=\"CR37\" citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. Nonetheless, its production has set many difficulties in the realization process. They are linked to the presence of at least 10 GBS strains showing a different capsular polysaccharide, which is the major virulence factor of the bacterium. Specifically, 6 of them (Ia, Ib, and II up to V) are the most frequently involved in invasive disease [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Finally, it is necessary both to establish the best administration time during pregnancy, and any potential harmful effects to the embryo and/or fetus [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. The results of research are ongoing, pointing at promising perspectives in obtaining a vaccination able to prevent invasive GBS disease in the majority of cases [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e].\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe present study revealed in our Department an increased prevalence of pregnant women screened for, and colonized by GBS, in the last decade. However, a lower frequency in the execution of vaginal-rectal swabs for GBS, as well as of adequate and complete IAP were found in the first two years of the study (2020\u0026ndash;2021) than in 2022. Such data are in accordance with those observed during the pandemic period for other care settings (especially emergency care areas, as well as surgery and diagnostic services), where significant delays in diagnosis and treatment, and increase in mortality/morbidity rates due to the indirect effects of COVID-19 (reduction in the number of clinical checks, fear in the access to health facilities) have been described. Furthermore, inequalities in the number of swabs performed persist, compared to the past, between Italian and foreign women, highlighting an insufficient health support provided to migrant and at risk populations. IAP is the only prophylactic method currently available and effective against neonatal GBS infection. Although this is an easy procedure to implement, and actually our population of women subjected to screening and undergoing prophylaxis increased in the last years, however adherence and uniformity in the management protocols are still not optimal, as documented by the rates in which IAP was inadequate/incomplete or even omitted. Furthermore, we reported significant EOD prevalence rates among children of mothers carrying risk factors. Although the total number of neonatal GBS infections is not reported to be overly high, as documented also in the present analysis, however the prophylactic measures adopted to date cannot be considered fully satisfactory, and should therefore be improved. Better skills integration and obstetrical-neonatal collaboration, in addition to new effective preventive tools, like vaccines able to prevent invasive disease, may allow further reduction in morbidity and mortality rates related to GBS perinatal infection.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEthics approval and consent to participate\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by the Mother and Child Department of the University of Palermo, ethics committee Palermo 1 (Palermo, Italy). All procedures performed in this report were in accordance with the ethical standards of the institutional and national research committee, and with the 1964 Helsinki declaration and its later amendments, or comparable ethical standards.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConsent for publication\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAvailability of data and materials\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCompeting interests\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe declare that the first and last author of the manuscript, Gregorio Serra and Giovanni Corsello, have the role, within Italian Journal of Pediatrics, as Associate Editor and Editor-in-chief respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFunding\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was granted for this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAuthors\u0026rsquo; contributions\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGS drafted the manuscript and took care of the patients. LLS performed the statistical analysis and drafted the first version of the paper. MGio gathered the data related to pregnant women. MGiu revised the manuscript. PT reviewed the literature, made the database and analyzed the data. RV supervised the study and revised the paper. GC conceived the study, revised the manuscript and gave final approval of the version to be submitted. All authors red and approved the manuscript as submitted.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWorld Health Organization. Group B Streptococcus Vaccine Development Technology Roadmap: Priority Activities for Development, Testing, Licensure and Global Availability of Group B Streptococcus Vaccines. 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Green-top Guideline 36 BJOG. 2017;124(12):e280\u0026ndash;305.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrevention of Group B Streptococcal Early-Onset Disease in Newborns. ACOG Committee Opinion, Number 797. Obstet Gynecol. 2020;135(2):e51\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchrag SJ, Verani JR. Intrapartum antibiotic prophylaxis for the prevention of perinatal group B streptococcal disease: experience in the United States and implications for a potential group B streptococcal vaccine. Vaccine. 2013;31(Suppl 4):D20\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhu Y, Lin XZ. Updates in prevention policies of early-onset group B streptococcal infection in newborns. Pediatr Neonatol. 2021;62(5):465\u0026ndash;75.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePuccio G, Cajozzo C, Canduscio LA, Cino L, Romano A, Schimmenti MG, Giuffr\u0026egrave; M, Corsello G. Epidemiology of Toxoplasma and CMV serology and of GBS colonization in pregnancy and neonatal outcome in a Sicilian population. Ital J Pediatr. 2014;40:23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBerardi A, Di Fazzio G, Gavioli S, Di Grande E, Groppi A, Papa I, Piccinini G, Simoni A, Tridapalli E, Volta A, Facchinetti F, Ferrari F, GBS Prevention Working Group. Emilia-Romagna. Universal antenatal screening for group B streptococcus in Emilia-Romagna. J Med Screen. 2011;18(2):60\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eInfezioni neonatali precoci e tardive da streptococco di gruppo B in Italia. Edited by Creti R. Roma: Istituto Superiore di Sanit\u0026agrave;. 2011. Rapporti ISTISAN 11/7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrevalence of maternal. colonisation with group B streptococcus: a systematic review and meta-analysis. Lancet Infect Dis. 2016;16(9):1076\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKwatra G, Cunnington MC, Merrall E, Adrian PV, Ip M, Klugman KP, Tam WH, Madhi SA, Berkley JA, Lowe BS, Mwangi I, Williams T, Bauni E, Mwarumba S, et al. Bacteremia among children admitted to a rural hospital in Kenya. N Engl J Med. 2005;352(1):39\u0026ndash;47.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChaudhary M, Rench MA, Baker CJ, Singh P, Hans C, Edwards MS. Group B Streptococcal Colonization Among Pregnant Women in Delhi, India. Pediatr Infect Dis J. 2017;36(7):665\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCosta NS, Rio-Tinto A, Pinto IBF, Dos Santos Silva Alvim DC, de Assis Rocha A, Oliveira LMA, Botelho ACN, Fracalanzza SEL, Teixeira LM, Rezende-Filho J, Marinho PS, Amim J\u0026uacute;nior J, Taylor S, Thomas S, Pinto TCA. Changes in Group B Streptococcus Colonization among Pregnant Women before and after the Onset of the COVID-19 Pandemic in Brazil. Pathogens. 2022;11(10):1104.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Dyke MK, Phares CR, Lynfield R, Thomas AR, Arnold KE, Craig AS, Mohle-Boetani J, Gershman K, Schaffner W, Petit S, Zansky SM, Morin CA, Spina NL, Wymore K, Harrison LH, Shutt KA, Bareta J, Bulens SN, Zell ER, Schuchat A, Schrag SJ. Evaluation of universal antenatal screening for group B streptococcus. N Engl J Med. 2009;360(25):2626\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchrag SJ, Zell ER, Lynfield R, Roome A, Arnold KE, Craig AS, Harrison LH, Reingold A, Stefonek K, Smith G, Gamble M, Schuchat A. Active Bacterial Core Surveillance Team. A population-based comparison of strategies to prevent early-onset group B streptococcal disease in neonates. N Engl J Med. 2002;347(4):233\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEdmond KM, Kortsalioudaki C, Scott S, Schrag SJ, Zaidi AK, Cousens S, Heath PT. Group B streptococcal disease in infants aged younger than 3 months: systematic review and meta-analysis. Lancet. 2012;379:547\u0026ndash;56.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaker CJ. Early onset group B streptococcal disease. J Pediatr. 1978;93(1):124\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePiro E, Serra G, Schierz IAM, Giuffr\u0026egrave; M, Corsello G. Fetal growth restriction: a growth pattern with fetal, neonatal and long-term consequences. Euromediterranean Biomedical J. 2019;14(09):038\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSerra G, Giuffr\u0026egrave; M, Piro E, Corsello G. The social role of pediatrics in the past and present times. Ital J Pediatr. 2021;47(1):239.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSerra G, Miceli V, Albano S, Corsello G. Perinatal and newborn care in a two years retrospective study in a first level peripheral hospital in Sicily (Italy). Ital J Pediatr. 2019;45(1):152.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoyer KM, Gadzala CA, Kelly PD, Gotoff SP. Selective intrapartum chemoprophylaxis of neonatal group B streptococcal early-onset disease. III. Interruption of mother-to-infant transmission. J Infect Dis. 1983;148:810\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnthony BF, Okada DM, Hobel CJ. Epidemiology of the group B streptococcus: maternal and nosocomial sources for infant acquisitions. J Pediatr. 1979;95(3):431\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGodambe S, Shah PS, Shah V. Breast milk as a source of late onset neonatal sepsis. Pediatr Infect Dis J. 2005;24(4):381\u0026ndash;2.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTrijbels-Smeulders MA, Koll\u0026eacute;e LA, Adriaanse AH, Kimpen JL, Gerards LJ. Neonatal group B streptococcal infection: incidence and strategies for prevention in Europe. Pediatr Infect Dis J. 2004;23(2):172\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohri AK, Paoletti LC, Glaser P, Dua M, Sharma PK, Grandi G, Rappuoli R. Group B Streptococcus: global incidence and vaccine development. Nat Rev Microbiol. 2006;4(12):932\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJordan HT, Farley MM, Craig A, Mohle-Boetani J, Harrison LH, Petit S, Lynfield R, Thomas A, Zansky S, Gershman K, Albanese BA, Schaffner W, Schrag SJ. Active Bacterial Core Surveillance (ABCs)/Emerging Infections Program Network, CDC. Revisiting the need for vaccine prevention of late-onset neonatal group B streptococcal disease: a multistate, population-based analysis. Pediatr Infect Dis J. 2008;27(12):1057\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMadhi SA, Anderson AS, Absalon J, Radley D, Simon R, Jongihlati B, Strehlau R, van Niekerk AM, Izu A, Naidoo N, Kwatra G, Ramsamy Y, Said M, Jones S, Jose L, Fairlie L, Barnabas SL, Newton R, Munson S, Jefferies Z, Pavliakova D, de Silmon NC, Gomme E, Perez JL, Scott DA, Gruber WC, Jansen KU. Potential for Maternally Administered Vaccine for Infant Group B Streptococcus. N Engl J Med. 2023;389(3):215\u0026ndash;27.\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":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"italian-journal-of-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"itjp","sideBox":"Learn more about [Italian Journal of Pediatrics](http://ijponline.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ITJP/default.aspx","title":"Italian Journal of Pediatrics","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Streptococcus agalactiae, GBS colonization, intrapartum antibiotic prophylaxis, neonatal sepsis, COVID-19","lastPublishedDoi":"10.21203/rs.3.rs-4189394/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4189394/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eGroup B \u003cem\u003eStreptococcus\u003c/em\u003e (GBS) is a major cause of sepsis and meningitis in newborns. The Centers for Disease Control and Prevention (CDC) recommends to pregnant women, between 35 and 37 weeks of gestation, universal vaginal-rectal screening for GBS colonization, aimed at \u003cem\u003eintrapartum\u003c/em\u003e antibiotic prophylaxis (IAP). The latter is the only currently available and highly effective method against GBS neonatal infections. Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, the preventive measures implemented to mitigate the effects of SARS-CoV-2 infection led to the reduction in the access to many health facilities and services, including the obstetric and perinatal ones. The purpose of the present study was to evaluate the prevalence rates of maternal GBS colonization, as well as use and effects of IAP in the newborn, in a population of pregnant women during (years 2020\u0026ndash;2021) and after (year 2022) the COVID-19 pandemic, also with the aim to establish possible epidemiological and clinical differences in the two subjects\u0026rsquo; groups.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003e We retrospectively analyzed the clinical data of pregnant women admitted to, and delivering, at the Gynaecology and Obstetrics Unit, Department of Sciences for Health Promotion and Mother and Child Care, of the University Hospital of Palermo, Italy, from 01.01.2020 to 31.12.2022. For each of them, we recorded pertinent socio-demographic information, clinical data related to pregnancy, delivery and \u003cem\u003eperipartum\u003c/em\u003e, and specifically execution and status of vaginal and rectal swab test for GBS detection, along with eventual administration and modality of IAP. The neonatal outcome was investigated in all cases at risk. The data observed during the pandemic (years 2020\u0026ndash;2021) were compared with those recorded in the following period (year 2022).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe present analysis involved 2109 pregnant women, in addition to their 2144 newborns. The vaginal-rectal swab for GBS was performed in 1559 (73.92%) individuals. The test resulted positive in 178 cases overall (11.42% of those undergoing the screening). Amongst our whole sample, 298 women had an indication for IAP, and 64 (21.48%) received adequate treatment; for 23 (7.72%) it was inadequate/incomplete, while 211 (70.8%) did not receive IAP. Comparing the pandemic period (years 2020\u0026ndash;2021) with the following one (year 2022), a lower incidence (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009\u003cem\u003e)\u003c/em\u003e in the execution of vaginal-rectal swabs for GBS was found (70.38% during \u003cem\u003evs\u003c/em\u003e 75.65% after) in the first two years, while a greater number (although not statistically significant, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.12) of adequate and complete IAP conducted in 2022, than in the previous biennium (26.36 \u003cem\u003evs\u003c/em\u003e 18.62%). During the study time, 13 neonates with early onset disease (EOD), out of 179 (7.3%) born to mothers with risk factors, were observed (the global prevalence on the total of babies delivered in the period under investigation was 6.06\u0026permil;). 3 among these patients\u0026rsquo; mothers performed incomplete IAP, while the others did not receive IAP. Neither cases of neonatal meningitis, nor deaths were observed.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThe present study revealed in our Department an increased prevalence of pregnant women screened for, and colonized by GBS, in the last decade. However, a significantly lower frequency of vaginal-rectal swabs performed for GBS, as well as a smaller number of adequate and complete IAP were found in the pandemic biennium (2020\u0026ndash;2021) than in the following year (2022). Such data are in accordance with those observed during the pandemic period for other care settings, where significant delays in diagnosis and treatment and increased mortality/morbidity rates, due to the indirect effects of COVID-19, have been described. Although IAP is an easy procedure to implement, however adherence and uniformity in the management protocols are still not optimal. In addition, significant EOD prevalence has been reported among children of mothers carrying risk factors. Therefore, the prophylactic measures adopted to date cannot be considered fully satisfactory, and should be improved. Better skills integration and obstetrical-neonatological collaboration, in addition to new effective preventive tools, like vaccines able to prevent invasive disease, may allow further reduction in morbidity and mortality rates related to GBS perinatal infection.\u003c/p\u003e","manuscriptTitle":"Group B streptococcus colonization in pregnancy and neonatal outcomes: a three-year monocentric retrospective study during and after the COVID-19 pandemic","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-04 18:56:08","doi":"10.21203/rs.3.rs-4189394/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2024-06-16T11:58:31+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-05-18T14:18:35+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-05-18T12:18:12+00:00","index":"","fulltext":""},{"type":"submitted","content":"Italian Journal of Pediatrics","date":"2024-04-25T04:42:55+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"italian-journal-of-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"itjp","sideBox":"Learn more about [Italian Journal of Pediatrics](http://ijponline.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ITJP/default.aspx","title":"Italian Journal of Pediatrics","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3138060d-9c6d-4a88-bb3b-fea5ae6f076b","owner":[],"postedDate":"June 4th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-09-16T16:08:50+00:00","versionOfRecord":{"articleIdentity":"rs-4189394","link":"https://doi.org/10.1186/s13052-024-01738-2","journal":{"identity":"italian-journal-of-pediatrics","isVorOnly":false,"title":"Italian Journal of Pediatrics"},"publishedOn":"2024-09-13 15:57:38","publishedOnDateReadable":"September 13th, 2024"},"versionCreatedAt":"2024-06-04 18:56:08","video":"","vorDoi":"10.1186/s13052-024-01738-2","vorDoiUrl":"https://doi.org/10.1186/s13052-024-01738-2","workflowStages":[]},"version":"v1","identity":"rs-4189394","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4189394","identity":"rs-4189394","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}