Dadi Belayneh Regasa, Sime Mulatu, Seid Mohamed, Tadesse Dagimawie, Siraj Munira, Alelign Dagninet, Solomon Zerihun
Department of Medical Microbiology, Arba Minch University, Arba Minch, Ethiopia.
Madda Walabu University, Robe, Ethiopia.
Can J Infect Dis Med Microbiol. 2022 Jul 11;2022:8163396. doi: 10.1155/2022/8163396. eCollection 2022.
Group B (GBS) contributes to maternal and neonatal morbidity and mortality by increasing intrauterine infection or vertical transmission at the time of birth. Despite many efforts to reduce the potential risk of vertical transmission, GBS remains the main cause of serious disease (neonatal sepsis, meningitis, and/or pneumonia) in vulnerable newborns during the first week of life. This study aimed to assess vertical transmission, risk factors, and antimicrobial resistance patterns of GBS among pregnant women and their neonates.
A facility-based cross-sectional study was conducted among mothers and their neonates from February to May 2021. A total of 201 pregnant women with their neonates participated in this study. A well-designed questionnaire was used to collect sociodemographic and clinical data. A vaginal swab from mother before delivery and neonatal nasal and ear canal swab samples were taken as soon as after delivery within 30 minutes. Vaginal swabs, neonatal ear canal, and nasal swabs were placed into Todd-Hewitt broth and incubated at 37°C for 18-24 hours at 35-37°C in 5% CO conditions and then subcultured on 5% sheep blood agar for 18-48 hours. Presumptive identification of GBS was made by morphology, Gram stain, catalase, and hemolytic activity on sheep blood agar plates. CAMP and bacitracin susceptibility tests were used as confirmatory tests for GBS. Data were analyzed using SPSS version 21. value ≤0.05 was considered statistically significant.
Vertical transmission rates of GBS (mother to neonates) were 11.9%. The prevalence of GBS among pregnant women and newborns was 24/201 (11.9%) (95% CI = 7.5-16.9) and 11/201 (5.5%) (95% CI = 2.5-9.0), respectively. The history of prolonged rupture of membranes (AOR = 3.5, CI = 2.2-18.8) and urinary tract infection (AOR = 2.9, CI = 1.7-16.3) were associated factors for maternal GBS colonization. Gestational age of <37 weeks (=0.008), low birth weight of <2.5 kg (=0.001), and maternal history of vaginal discharge (=0.048) were associated factors for neonatal GBS colonization. Low antibiotic resistance was observed for erythromycin 8.6%, clindamycin 5.7%, and chloramphenicol 2.9%.
In this study, high vertical transmission (mother to neonates) rate was observed. The prevalence of vaginal GBS colonization of women at delivery was 11.9% and significantly associated with the history of prolonged rupture of membranes and urinary tract infections. Gestational age of <37 weeks, low birth weight of <2.5 kg, and maternal history of vaginal discharge were associated with neonatal GBS colonization. Hence, there is a need for antenatal culture-based GBS screening, risk factor-based interventions, and regular follow-up of drug resistance patterns for proper treatment and management of GBS.
B族链球菌（GBS）通过增加宫内感染或分娩时的垂直传播，导致孕产妇和新生儿发病和死亡。尽管为降低垂直传播的潜在风险做出了许多努力，但GBS仍然是脆弱新生儿出生后第一周严重疾病（新生儿败血症、脑膜炎和/或肺炎）的主要原因。本研究旨在评估孕妇及其新生儿中GBS的垂直传播、危险因素和抗菌药物耐药模式。
2021年2月至5月，在一家医疗机构对母亲及其新生儿进行了一项基于机构的横断面研究。共有201名孕妇及其新生儿参与了本研究。使用精心设计的问卷收集社会人口学和临床数据。在分娩前采集母亲的阴道拭子，并在分娩后30分钟内尽快采集新生儿的鼻腔和耳道拭子样本。将阴道拭子、新生儿耳道和鼻腔拭子放入托德-休伊特肉汤中，在37°C下于含5%二氧化碳的条件下培养18 - 24小时，然后在5%羊血琼脂上继代培养18 - 48小时。通过形态学、革兰氏染色、过氧化氢酶和在羊血琼脂平板上的溶血活性对GBS进行初步鉴定。CAMP试验和杆菌肽敏感性试验用作GBS的确诊试验。使用SPSS 21版软件进行数据分析。P值≤0.05被认为具有统计学意义。
GBS的垂直传播率（母亲传给新生儿）为11.9%。孕妇和新生儿中GBS的患病率分别为24/201（11.9%）（95%置信区间=7.5 - 16.9）和11/201（5.5%）（95%置信区间=2.5 - 9.0）。胎膜早破病史（调整后比值比[AOR]=3.5，置信区间=2.2 - 18.8）和尿路感染病史（AOR = 2.9，置信区间=1.7 - 16.3）是孕产妇GBS定植的相关因素。孕周<37周（P = 0.008）、出生体重<2.5 kg（P = 0.001）和母亲有阴道分泌物病史（P = 0.048）是新生儿GBS定植的相关因素。观察到对红霉素的耐药率较低，为8.6%，对克林霉素为5.7%，对氯霉素为2.9%。
在本研究中，观察到较高的垂直传播率（母亲传给新生儿）。分娩时女性阴道GBS定植率为11.9%，且与胎膜早破病史和尿路感染显著相关。孕周<37周、出生体重<2.5 kg和母亲有阴道分泌物病史与新生儿GBS定植有关。因此，需要基于产前培养的GBS筛查、基于危险因素的干预措施以及定期监测耐药模式，以对GBS进行适当的治疗和管理。
