New research published in PLOS Medicine shows a high burden of sexually transmitted infections and bacterial vaginosis among young people in rural South Africa.
The study, led by researchers from the London School of Hygiene & Tropical Medicine and the Africa Research Health Institute, found that young women were more than twice as likely to be infected with chlamydia (5% in men and 11% in women), and nearly twice as likely to be infected with genital herpes (17% in men and 29% in women).
The research, which involved 447 people aged between 15 and 24, also found that 42% of young women had a condition called bacterial vaginosis (BV). BV is a known risk factor for poor birth outcomes and HIV acquisition. The young women in the study were also five times as likely to be infected with a tiny parasite called Trichomonas vaginalis (0.6% in men and 5% in women).
Left untreated, STIs can cause serious health complications and permanent damage. Chlamydia, a curable STI, is a major cause of pelvic inflammatory disease, chronic pelvic pain and infertility. Pregnant women can also pass the infection on to their baby during delivery, which can cause pneumonia and eye infections in newborns. Women infected with chlamydia are also at a higher risk of contracting HIV.
In this study, which was conducted at the Africa Health Research Institute’s health and demographic surveillance site in uMkhanyakude, KwaZulu-Natal, researchers collected samples from participants at their homes. The samples were then sent to a central laboratory and tested for chlamydia, gonorrhoea, syphilis, trichomoniasis and genital herpes (herpes simplex virus type 2). Women were also screened for bacterial vaginosis.
The home-based sample collection for STIs was found to be acceptable to participants, and they reported that the sampling was easy, not painful and they did not experience any anxiety or embarrassment.
Although South Africa is known to have a high prevalence of HIV, less is known about the burden of STIs, especially among young people, and risk factors for acquiring STIs. Having accurate data on STI prevalence and incidence is vital for prevention and programme planning and the World Health Organization made this a priority in their Strategy on Sexually Transmitted Infections.
“Adolescents and young adults are particularly vulnerable to STIs, yet STI prevalence is largely unknown in many high HIV prevalence settings, as these types of studies can be expensive to carry out. To date there have been few population estimates of the burden of STIs among young adults known to be at high risk of infection, such as adolescent girls and young women, and no studies among men. These estimates are crucial so that we can detect increases in STIs, and plan effective prevention and control programmes,” said Suzanna Francis, Assistant Professor and lead author from the London School of Hygiene & Tropical Medicine.
“We found a high burden of STIs in this study, most of which were asymptomatic. Current STI control programmes in low and middle-income countries rely on people experiencing symptoms in order to be diagnosed, which misses many infections. Incorporating the results of STI surveys like this, into existing networks of health and demographic surveillance sites is an excellent opportunity to obtain STI prevalence estimates that are badly needed,” Francis added.
The authors say the study shows vital STI prevalence data can be efficiently obtained in areas where the impact of STIs and their consequences may be greatest. They also note that future studies should be carried out in conjunction with research that measures STI/BV prevalence in high-risk populations, such as female sex workers, to provide robust prevalence estimates.
The authors acknowledge limitations of their work, including that the study was limited by a time constraint of three months in which fewer participants were contacted and enrolled than envisaged.
This study was funded by the Wellcome Trust, the Medical Research Council and ViiV Healthcare.
Top image: A nurse prepares for a home visit for the study. Photo: Lerato Mchunu