YI5 - Effect of antenatal Chlamydia trachomatis and Neisseria gonorrhoeae screening on post-delivery prevalence and vertical transmission in Gaborone, Botswana

Background: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are among the most common sexually transmitted pathogens globally. If untreated in pregnant women, CT and NG can be transmitted to neonates during childbirth which can lead to eye and respiratory infections. Routine antenatal screening for CT/NG is not available in most low- and middle-income countries.



Methods: The Maduo Study was a cluster-controlled trial to evaluate the effect of antenatal CT and NG screening on post-delivery prevalence and vertical transmission of CT/NG compared to the standard-of-care in Botswana (February 2021-December 2022). Pregnant women ≥15 years, attending their first antenatal care visit, ≤27 weeks gestation, and asymptomatic (defined as not treated syndromically for an STI in the last month) were eligible. The intervention arm received CT and NG testing (Cepheid GeneXpert®) at first antenatal care, third trimester, and 6-8 weeks post-delivery. The standard-of-care arm received CT and NG testing at their postnatal visit only. Infants of women who tested positive postnatally were tested for CT and NG.




Results: The study enrolled 500 women; 85% were retained and tested post-delivery. CT prevalence in the intervention arm was reduced from 23% (57/251) at enrolment to 1% (3/220) post-delivery (difference: 21%; 95% CI 16-27%). NG prevalence was reduced from 1% (3/251) at enrolment to 0% post-delivery (difference: 1%; 95% CI 0-3%). Post-delivery CT and NG prevalence in the standard-of-care arm was 13% (26/206) and 1% (2/206), respectively. The difference in CT and NG prevalence between study arms post-delivery was 11% (95% CI 6-16%) and 1% (95% CI 0-2%), respectively. Among 31 infants (1 set of twins) of mothers positive for CT/NG post-delivery (CT: 29; NG: 1; CT & NG: 1), 11 (35%) tested positive for CT/NG infection (CT: 10; NG: 1). Six of eleven infants with CT/NG infection (55%) were symptomatic for pneumonia or conjunctivitis.





Conclusion: Antenatal screening substantially reduced the post-delivery prevalence of CT/NG among women asymptomatic for STIs at their first antenatal care visit. Among women positive for CT/NG post-delivery, one-third transmitted the infection to their neonates. These findings highlight the need for screening pregnant women during antenatal care to reduce adverse newborn outcomes in settings such as Botswana.