The prevalence of chlamydia and other sexually transmitted infections among women attending Vaiola hospital antenatal clinic in Tonga

Abstract

Objective: To determine the prevalence and risk factors for chlamydia, gonorrhoea, hepatitis B, HIV, and syphilis among pregnant women attending an antenatal clinic in Tonga. Methods: A cross sectional study was conducted among pregnant women attending for their first visit to the antenatal clinic at Vaiola Hospital in Tongatapu, Tonga, during the period August to November 2015. Sociodemographic and behavioural characteristics were collected by interviewer-administered questionnaire. These data were then linked to urine test results for the presence of chlamydia and gonorrhoea and serological results for hepatitis B, HIV and syphilis. Results: Data were collected from 500 women. Of the 486 (97.2%) and 96 (19.2%) women whose urine were screened for chlamydia and gonorrhoea, C. trachomatis and N. gonorrhoeae were found in 79 (16.3%; 95% CI: 13.2-19.8) and 3 (3.1%; 95% CI: 1.1-8.8) cases respectively. Of the 500 women whose bloods were tested for hepatitis B, HIV and syphilis, hepatitis B surface antigen was found in 22 (4.4%; 95% CI: 2.9-6.6) cases and no HIV or RPR seropositive cases were found. Multivariate analysis showed that among women < 25 years, the risk of chlamydia infection was increased in those having more than one sexual partner in the past 12 months (AOR= 4.28 95% CI: 2.04-8.89 p<0.01), being nulliparous (AOR= 2.32 95% CI: 1.30-4.14 p<0.01) and having an unusual vaginal or anal discharge (AOR= 2.60 95% CI: 1.19-5.50 p<0.01). Conclusions: Chlamydia was the most common infection in this population, especially amongst women less than 25 years of age. This has the potential to significantly impact on the future health of both the women and neonates thus highlighting the need to prioritise chlamydia testing in pregnant women. Further studies are needed to evaluate STI specific testing guidelines and the roles of prevention strategies for pregnant women in this age group in Tonga.