Prevalence of group B Streptococcus colonization among pregnant women attending antenatal clinic of Hawassa Health Center, Hawassa, Ethiopia

Background: Group B streptococcus (GBS) or Streptococcus agalactiae are members of the normal flora of the female genital tract. GBS has become the major cause of bacterial infections in the peri-natal period, including bacteraemia, amnionitis, endometritis, and urinary tract infection in pregnant women as well as sepsis and meningitis in neonates and young infants. Infection of the new born may be acquired by the intra-amniotic route or directly during passage through the birth canal. Objectives: This study was undertaken to determine the prevalence of group B Streptococcus (GBS) colonization and to analyze related risk factors among pregnant women attending the antenatal clinic of Hawassa Health centre, Adare Hospital Hawassa, Ethiopia. Methods: A total of 139 pregnant women were screened for GBS colonization between May and June 2010. Standard microbiological methods were used to isolate and identify GBS from vaginal and ano-rectal swabs obtained from study subjects. An antimicrobial susceptibility test was performed for all GBS isolates according to the criteria of the Clinical and laboratory Standards Institute (CLSI) by disk diffusion method. Results: A total of 29 out of 139 (20.9%) pregnant women were colonized by GBS. No statistically significant association was observed for GBS colonization with any of socio-demographic characteristics of the study subjects including age, occupation, type of contraceptive used, parity, number of antenatal clinic visits. All GBS strains were susceptible to penicillin, ampicillin, vancomycin and gentamicin. Resistance was observed against erythromycin (6.9%), tetracycline (48.2%), ceftriaxone (10.3%), chloramphenicol (51.7%), ciprofloxacin (13.8%) and norfloxacin (10.3%). Conclusion: This study showed that prevalence of GBS colonization was 20.9% among the study subjects. The finding of this study was comparable with findings reported from developed and developing countries. However, further epidemiological investigations should be done in different parts of the country in order to know the actual GBS colonization rate in pregnant women and to consider the use of intra-partum antibiotics prophylaxis for prevention of early onset GBS-neonatal diseases. [Ethiop. J. Health Dev. 2012;26(1):36-42]