(P277) Prevalence and incidence of Chlamydia trachomatis and Neisseria gonorrhoeae among pregnant women in a high HIV prevalence setting in South Africa

Wednesday, July 26, 2023

16:00 – 18:00 CST

Primary Presenter(s)

RG

Ranjana M S Gigi, MMed, PhD student

MD-PhD student
1) Institute of Social and Preventive Medicine, University of Bern, Switzerland 2) Research Unit, Foundation for Professional Development, South Africa, Eastern Cape, South Africa

Co-author(s)

MM

Mandisa Mildred Mdingi, MSc (she/her/hers)

Research Project Manager
Foundation for Professional Development
Black, Eastern Cape, South Africa
Christina A. Muzny, MD, MSPH (she/her/hers)

Associate Professor of Medicine, Epidemiology, and Obstetrics & Gynecology
Division of Infectious Diseases, University of Alabama at Birmingham
Birmingham, Alabama, United States
CT

Christopher M. Taylor, PhD

Department of Microbiology, Immunology, and Parasitology, Louisiana Health Sciences Center New Orleans, United States
Chibuzor M. Babalola, MD, MPH

Postdoctoral Research Associate & Part-time Professor
Keck School of Medicine Department of Population and Public Health Sciences, University of Southern California, United States
AM

Andrew Medina-Marino

Desmond Tutu Health Foundation, South Africa, United States
Jeffrey D. Klausner, MD (he/him/his)

Clinical Professor
Department of Population and Public Health Sciences, University of Southern California
Los Angeles, California, United States
Remco P.H Peters, MD, PhD

Head of Clinical Research
Foundation for Professional Development
East London, South Africa
Nicola Low, MD (she/her/hers)

Professor of Epidemiology and Public Health
University of Bern
Bern, Bern, Switzerland

Background

Sexually transmitted infections (STIs) among pregnant women in South Africa have been reported to be more common among women living with HIV (WLHIV) than among HIV-negative women. The objectives of this study were to investigate the prevalence and incidence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) and their associations with HIV infection in pregnancy.

Methods

CT/NG testing was implemented in an ongoing cohort study about STIs in pregnancy in a primary healthcare clinic in East London, South Africa. At the baseline antenatal care visit before 27 weeks of gestation and between 30-34 weeks, an HIV rapid test was done, and a nurse-collected vaginal swab was tested using the GeneXpert CT/NG assay. Women with positive results were offered treatment. We calculated percentages, relative risks (RR) and incidence rates per 100 woman-years (with 95% confidence intervals, CI).

Results

From March 2021 to November 2022, we tested 215 women at baseline and at 30-34 weeks gestation. At baseline, 43 women were CT and/or NG-positive; CT 40/215 (19%, CI 14-25), NG 9/215 (4%, CI 2-8) (6 CT and NG), and 57 were WLHIV (27%, CI 21-33). The risk of CT/NG was 12% (7/57) in WLHIV and 23% (36/158) in HIV-negative women (RR 0.5, CI 0.3-1.1). CT/NG appeared to be less common in women reporting condom use at last intercourse (RR 0.38, CI 0.1-1.5) and more common among women reporting >1 partner in the last 6 months (1.4, CI 0.7-3.0). Most women with positive results (41/43) returned for treatment. At the 30-34 week visit, 16 (7%) women were CT-positive and 1 (0.5%) was NG-positive. CT/NG incidence among HIV-negative women (9 CT and 1 NG) was 0.1 (CI0.07-0.3) per 100 woman-years. There were no incident infections in WLHIV. Of 7 women with repeat positive CT results, 2/7 (29%) were WLHIV and 5/36 (14%) HIV-negative.

Conclusion

CT and NG were highly prevalent in this cohort. Compared with HIV-negative women, WLHIV appeared less likely to have CT/NG at baseline and at follow-up. Over half of the positive results at 30-34 weeks (10/17) were new infections, highlighting the need for monitoring of incident CT/NG in late pregnancy.