Streptococcus agalactiae colonization and correlation with HIV-1 and HBV seroprevalence in pregnant women from Zimbabwe.

Objective: To estimate the frequency of coinfection of Streptococcus agalactiae or Group B streptococcus (GBS), hepatitis B virus (HBV) and HIV-1 in pregnant women and evaluate any association between them.

Study Design: Three health centres from rural, rural-urban and urban communities were selected and at least 369 pregnant women had samples available for simultaneous analysis of GBS colonization rates, and HIV and HBV seroprevalence rates. Swabs were collected at two different stages in the course of pregnancy and at delivery to isolate GBS. Serum samples were collected at recruitment for analysis of standard HBV seromarkers and the presence of HIV-1. The odds ratio (95% CI) and chi(2) tests were used for analysis of the results at a level of significance set at
Results: Single infections with GBS, HBV and HIV-1 were found to be 35.7%, 3.3% and 20.1% respectively. The HIV-1 prevalence rate was 14.1%, 23.1% and 19.5% for the rural, rural-urban and urban communities respectively. The HBV prevalence rates were 3.3%, 3.0% and 3.7% for Chitsungo, Guruve and Harare respectively. There were no significant differences in HBV prevalence rates among the three communities. Simultaneous coinfection with GBS, HBV and HIV-1 was registered in only one (0.3%) of the women. The prevalence of coinfection with GBS/HBV, GBS/HIV-1 and HBV/HIV-1 was 0.5%, 9.2% and 0.8% respectively. The prevalence rate of GBS/HIV-1 coinfection was significantly higher in the rural-urban than the two other communities (p<0.001).

Conclusions: There was a high prevalence of single infections with GBS and HIV-1 but a lower HBV prevalence among pregnant women studied compared to other studies in Zimbabwe. Coinfection with GBS/HIV-1 was more common than GBS/HBV and HBV/HIV-1. Coinfection with HIV-1 and HBV did not differ between GBS colonized and GBS negative women. There was no difference in GBS colonization rate between HIV-1 positive and HIV-1 negative pregnant women.