Reproductive tract infections and sexually transmitted infections continue to cause considerable morbidity among pregnant women. Prevalence of these infections in this cohort is high with more than fifty percent of the women presenting with either a positive serogical STI or a vaginal infection. HSV-2 was the most prevalent STI, whilst syphilis was the least prevalent.
HIV prevalence in this cohort is within the range of figures reported in the country at that time [3, 18]. Syphilis is a routinely screened infection in pregnancy and if the women had booked for antenatal care in their first trimester there are higher chances that they could have been treated. The prevalence of HSV-2, T. vaginalis and BV in our study is consistent with what has been reported in the country, although most of the studies did not report on pregnant populations [5, 7, 8, 15–20]. Prevalence of Candidiasis in this cohort is much higher compared to the 25% reported by Mbizvo in 2001 .
High vaginal pH was the strongest predictor of having a vaginal infection. It has been reported that women in Zimbabwe practice vaginal douching, which to a large extend disturb their normal vaginal flora predisposing them to infections .
Different predictors were observed for serological STIs and vaginal infections because the former are chronic in nature whilst the latter are acute infections which can be completely cured. Due to the cross sectional design of the study we cannot establish which infection came first, HIV, syphilis or HSV-2 [[8, 9, 17], and ].
Association of increasing age with a positive serological STI are because older women have been sexually active for a longer period, thereby increasing their exposure to infections. Polygamous relationships lead to sexual partner mixing and infidelity, as the women's partners seek other sexual partners or vice versa .
Those having an income could have been exposed to infections by offering sexual favours in return for casual work to earn some income. This study was conducted at the time when levels of unemployment were quite high compounded by high inflation in the country [2, 23].
High morbidity of vaginal infections among young women and their association with teenage sexual debut is consistent with what has been reported; as their genital tract are not fully developed, this exposes them to higher risk of STI/RTIs acquisition [16, 20]. Association of multigravid and multiparity with testing positive for a serological STI is due to longer periods of unprotected sex as couples seek to conceive; this increases their risks of infection.
History of stillbirths and infant deaths' association with STI seropositivity is consistent with studies reporting that maternal STIs have a direct impact on the outcome of the infants . Ulcerative diseases increase risk of contracting HIV and other STIs thus Clinical genital ulcers and warts were positive predictors for testing positive for a serological STI [10, 11].
Seventy five percent of reported previous infections predicted testing positive for a serological STI. Self reporting of previous infections is quite high (25%) in this cohort compared to what was reported in another study where none of the women reported any previous infections . Acknowledgement of one's previous infections can be attributed to the positive impact of the counseling that the women receive through PMTCT VCT.
Self-reporting of STI symptoms is a positive observation as it compels one to seek medical treatment early. Seeking prompt treatment for STI symptoms will increase women's chances of being counseled to take an HIV test together with their sexual partners. Once screened for HIV women will then seek to protect themselves from infection and re-infections for those testing positive.
Contraceptive and condom use was quite high in our study, above sixty percent compared to what has been reported both in the Demographic Health Surveys (DHS) and other studies .
The association between condom use and testing positive for a serological STI is due to the chronic nature of the infections, where once infected one remains positive throughout their life time. Positive behaviour change after an HIV test has been reported in behavioral studies where those testing positive are likely to use condoms consistently. Use of condoms will in turn protect them against vaginal infections.
Sexual partners' characteristics were strong predictors for a positive serological STI reflecting on the role of sexual partners in fueling these infections. The higher partner age gap is because male partners are sexually active for a longer period with multiple sexual partners which exposes them to infections [[1, 5], and ]. For a meaningful impact to be achieved in preventing STI/RTI infections, interventions should target health education that involves and promotes positive behavior changes among males.
Women in this study had a considerably high STI/RTI morbidity in pregnancy despite the reported positive behaviour of increased condom use, and reduced number of sexual partners in the preceding year. Two years after PMTCT was initiated, reported positive behaviour change is noted. Our data supports the observed declines in HIV prevalence associated with behaviour changes [3, 18].
The strength of this study is that it was conducted at the time when the epidemic had reached a mature stage; characterized with declines in HIV prevalence and incidence attributed to a reduction in STI/RTIs and positive behaviour changes too.