Prevalence, incidence and associated risk factors of STIs during pregnancy in South Africa

Abstract

ObjectiveSTIs during pregnancy increase adverse pregnancy and birth outcomes and may increase HIV risk. STI syndromic management is standard of care in South Africa. Our study evaluated the prevalence and incidence of STIs in pregnant women and the associated risk factors.MethodsWe combined data from two prospective observational studies of pregnant women enrolled while attending their first antenatal clinic (ANC) visit in Tshwane District and Cape Town. Women ≥18 years were tested at first ANC visit and at their first postpartum visit for Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis using Xpert assays (Cepheid, USA). We evaluated the prevalence and incidence of STI and the associated risk factors using multivariable regression models.ResultsWe enrolled 669 pregnant women, 64% (n=427) from Tshwane District and 36% (n=242) from Cape Town; 80% (n=534) were women living with HIV (WLHIV) and 20% (n=135) without HIV. At enrolment, 37% (n=250) were diagnosed with at least one STI, of which 76% (n=190) were asymptomatic. STI prevalence was 40% (n=213) in WLHIV and 27% (n=37) in women without HIV (p=0.01). Baseline STI infection was associated with younger age (OR=0.95 per year, 95% CI 0.92 to 0.98), higher gestational age (adjusted OR (aOR)=1.03 per week, 95% CI 1.00 to 1.05), single relationship status (aOR=1.53, 95% CI 1.09 to 2.15) and HIV status (aOR=1.86, 95% CI 1.17 to 2.95). Of 419 participants with no STI at baseline, 21 had an incident STI during follow-up, with a mean follow-up time of 140 days. The incidence rate of STI during pregnancy and early post partum was 15 infections per 100 women-years (95% CI 9 to 23). Younger age was associated with STI incidence.ConclusionOur study shows high prevalence and incidence of STIs in pregnancy, especially in WLHIV, demonstrating the need for STI screening in ANC to prevent adverse pregnancy and birth outcomes. Most STI cases were asymptomatic and would have gone untreated with syndromic management. Aetiological STI screening is urgently needed to reduce the burden of STIs in pregnancy.

Sexually transmitted infections in pregnant women from sub-Saharan Africa

“…5,8,45,51,52,53,57,58,59 The prevalence estimates for C. trachomatis amongst antenatal women ranges from 6.5% to 36.8% in South Africa (Table 1). 2,9,18,19,20,22,30,36,37,60 Studies conducted in SSA amongst antenatal women reported prevalence estimates for N. gonorrhoeae ranging from 0% to 21.1%. 5,8,11,21,45,51,52,53,57,58,60 In South Africa amongst women attending antenatal clinic, the prevalence estimates for N. gonorrhoeae range from 0% to 6.9% (Table 1).…”

“…6,21 Untreated STIs are related with adverse outcomes during pregnancy including stillbirth, preterm labour and delivery and low birth weight. 20,22,23,24 Furthermore, STIs have been shown to increase the risk of HIV acquisition and motherto-child transmission (MTCT), and the risk is highest in women with multiple STIs. 2,25,26 Sub-Saharan Africa bears a heavy HIV burden, 27 and South Africa has the vast majority of people living with HIV worldwide, with 7.9 million people living with HIV in 2018.…”

“… 16 , 17 Recent studies in SSA have shown a high prevalence of curable STIs amongst pregnant women, and therefore the burden of STIs and HIV in SSA remains a significant threat to reproductive health. 18 , 19 , 20 Women infected with STIs can experience a variety of symptoms, including vaginal itching or irritation, vaginal discharge and dysuria, as well as more severe complications such as pelvic inflammatory disease and fallopian tube pathology. 6 , 21 Untreated STIs are related with adverse outcomes during pregnancy including stillbirth, preterm labour and delivery and low birth weight.…”

“… 6 , 21 Untreated STIs are related with adverse outcomes during pregnancy including stillbirth, preterm labour and delivery and low birth weight. 20 , 22 , 23 , 24 Furthermore, STIs have been shown to increase the risk of HIV acquisition and mother-to-child transmission (MTCT), and the risk is highest in women with multiple STIs. 2 , 25 , 26 …”

“…3 , 32 , 33 The syndromic approach treats STIs according to the presence of clinical signs and symptoms, rather than by laboratory-based diagnosis. 20 , 32 However, the inadequate specificity and sensitivity of this approach contributes to both over and undertreatment and poor antimicrobial stewardship may increase the risk of antibiotic resistance. 1 , 34 As a significant percentage of women who have STIs are asymptomatic, they are left untreated, and this may contribute to many adverse birth outcomes.…”