MATERNAL GROUP B STREPTOCOCCUS RECTO VAGINAL COLONIZATION IN HARAR, EASTERN ETHIOPIA: MAGNITUDE, VERTICAL TRANSMISSION AND DRUG SUSCEPTIBILITY PATTERN

Abstract

Background: Group B streptococci are a major cause of foetal infection and neonatal pneumonia, septicaemia and meningitis in developing countries due to vertical transmission from mother to the fetus and newborn. This vertical transmission is largely preventable using intrapartum antibiotic prophylaxis (IAP). However, high number of fetus and infants in developing countries are dying due to lack of information and thus lack of appropriate interventions. xiv Aim: The aim of this dissertation was to assess the magnitude of Maternal Group B streptococcal Recto-vaginal colonization, vertical transmission and drug susceptibility pattern among pregnant women in Eastern Ethiopia. Methods: Pregnant women admitted at labour and delivery room were studied. Samples were taken proportional to the client volume of the Hiwot Fana Specialized University Hospital, Jugal Hospital and Arategna health Center. They were interviewed, their clinical record reviewed, and laboratory test done. Maternal group B streptococcal recto-vaginal colonization was investigated by collecting swabs from both rectum and vagina, cultured on to Todd-Hewitt broth medium supplemented with Gentamicin and Nalidixic acid, and subsequently sub-cultured on 5 % sheep blood agar followed by identification of isolates based on colonial morphology, gram stain, catalase reaction, hippurate hydrolysis and Christie, Atkins, Munch-Petersen (CAMP) test. Vertical transmission was examined by collecting swabs specimen from the ear canal, umbilical, axilla, groin or nose within six hours after birth, similar culture and biochemical test done to identify group B streptococcus bacteria. Stillbirth was explored from medical record by using checklist. Antibiotic susceptibility testing was performed by disk diffusion method, then inducible clindamycin resistance by erythromycin investigated by D-test. The data were collected via structured questionnaire and checklist and double entered in to EpiData software (version- 3.1) and analyzed using STATA software (version-14). Log binomial, Logistic, and Robust Poisson regression models were used for the analysis, as deemed appropriately. Association was expressed as prevalence ratios (PR), Odds ratio (OR), and their 95% confidence interval. Results: Overall, the magnitude of recto-vaginal group B streptococcus colonization in pregnant women was 13.68% (95% CI: 12.04-15.32). GBS recto-vaginal colonization was more prevalent among adolescent, illiterate and lower wealth index women. The vertical transmission rate of GBS from colonized pregnant women was 45.02% (95% CI: 38.49, 51.68). Pre-labor rupture of membranes at term, prolonged rupture of the membrane ≥18 hours, and intrapartum maternal fevers were significantly associated with vertical transmission of GBS. Intrapartum antibiotic Prophylaxis (IAP) received ≥4 hours before delivery were reduce xv vertical transmission by 83% (APR= 0.17; 95% CI; 0.09-0.30). The odds of having a stillbirth was 8.93 times higher among recto- vaginal GBS colonized pregnant women (AOR= 8.93; 95% CI; 5.47, 14.56) Double disk diffusion test for susceptibility to GBS strain to currently used antibiotics was very high resistance; 56 (24.24%) to Erythromycin and 53 (22.94%) to Clindamycin. Reported antibiotics used, in the index pregnancy two weeks preceding the data collection was significantly associated with erythromycin and clindamycin resistance. Conclusion: Vertical transmission of GBS from colonized pregnant women is very high. Resistance to erythromycin and clindamycin antibiotics are also high. Screening pregnant women for maternal GBS colonization and use of IAP for colonized women is imperative to prevent vertical transmission and reduce stillbirth and neonatal morbidity and mortality.