Pre-exposure prophylaxis (PrEP) – taking antiretroviral drugs to protect people from acquiring HIV infection – is revolutionising the prevention of HIV around the world. However, a global study co-led by the London School of Hygiene & Tropical Medicine and Monash University in Australia, has shown that people who are seeking PrEP to prevent HIV are also at high risk of other sexually transmitted infections (STIs). Supported by the World Health Organisation, the study suggests PrEP services could be an ideal place to test for, prevent and treat both HIV and other STIs.
The review highlights the limited focus and investment in STI management within HIV programmes. It found that a quarter (24%) of people initiating PrEP were diagnosed with either chlamydia, gonorrhoea or syphilis before they started taking PrEP. Nearly three-quarters (72%) of those continuing to use PrEP were diagnosed with either chlamydia, gonorrhoea or syphilis within a year of starting PrEP.
The research team found that the same factors that place people at substantial risk for HIV, such as low condom use, barriers to accessing or using condoms and having more than one sexual partner, also increase their risk for acquiring other STIs.
Dr Jason Ong, co-lead author from the London School of Hygiene & Tropical Medicine and Monash University, said: “This global systematic review of the prevalence and incidence of STIs among users of pre-exposure prophylaxis for HIV identified 88 studies from 26 countries. We found a high prevalence of STIs in those starting PrEP, demonstrating that these programmes are targeting high-risk individuals for HIV and other STIs, and high incidence of STIs in those persisting on PrEP. This underscores the need for ongoing sexual health services.
“HIV PrEP programmes continue to be scaled-up globally. This offers an unprecedented opportunity to strengthen sexual health services through this growing infrastructure to high-risk populations that are now regularly engaged in our health system. PrEP programs can be a gateway to offer comprehensive sexual health care which should not only diagnose and treat STIs, but also offer vaccination, mental health support, substance use support and reproductive health services.”
PrEP consists of a combination of tenofovir and emtricitabine. It has been recommended for people at substantial HIV risk, such as men who have sex with men and people who inject drugs, by WHO since 2015.
Although most experience of PrEP implementation has been in high-income countries, PrEP services are now being developed for low- and middle-income countries. To date, more than 60 countries globally have national PrEP polices, including 20 in Africa.
Dr Rachel Baggaley from WHO’s department for HIV, hepatitis and sexually transmitted infections, a co-author of the article said: “High numbers of curable STIs are being missed particularly in low- and middle-income countries. PrEP services can help prevent not just HIV but also STIs, and we should take advantage of this opportunity.”
Melbourne Sexual Health Centre director Professor Christopher Fairley, said, “PrEP has the potential to be one of the most significant and powerful interventions to prevent HIV infection, and this paper has now highlighted an additional advantage of PrEP; that it provides an opportunity to improve the sexual health of those individuals and populations at highest risk of both HIV and STIs.”
Importance: Despite a global increase in sexually transmitted infections (STIs), there is limited focus and investment in STI management within HIV programs, in which risks for STIs are likely to be elevated.
Objective: To estimate the prevalence of STIs at initiation of HIV preexposure prophylaxis (PrEP; emtricitabine and tenofovir disoproxil fumarate) and the incidence of STIs during PrEP use.
Data Sources: Nine databases were searched up to November 20, 2018, without language restrictions. The implementers of PrEP were also approached for additional unpublished data.
Study Selection: Studies reporting STI prevalence and/or incidence among PrEP users were included.
Data Extraction and Synthesis: Data were extracted independently by at least 2 reviewers. The methodological quality of studies was assessed using the Joanna Briggs Institute critical assessment tool for prevalence and incidence studies. Random-effects meta-analysis was performed.
Main Outcomes and Measures: Pooled STI prevalence (ie, within 3 months of PrEP initiation) and STI incidence (ie, during PrEP use, after 3 months).
Results: Of the 3325 articles identified, 88 were included (71 published and 17 unpublished). Data came from 26 countries; 62 studies (70%) were from high-income countries, and 58 studies (66%) were from programs only for men who have sex with men. In studies reporting a composite outcome of chlamydia, gonorrhea, and early syphilis, the pooled prevalence was 23.9% (95% CI, 18.6%-29.6%) before starting PrEP. The prevalence of the STI pathogen by anatomical site showed that prevalence was highest in the anorectum (chlamydia, 8.5% [95% CI, 6.3%-11.0%]; gonorrhea, 9.3% [95% CI, 4.7%-15.2%]) compared with genital sites (chlamydia, 4.0% [95% CI, 2.0%-6.6%]; gonorrhea, 2.1% [95% CI, 0.9%-3.7%]) and oropharyngeal sites (chlamydia, 2.4% [95% CI, 0.9%-4.5%]; gonorrhea, 4.9% [95% CI, 1.9%-9.1%]). The pooled incidence of studies reporting the composite outcome of chlamydia, gonorrhea, and early syphilis was 72.2 per 100 person-years (95% CI, 60.5-86.2 per 100 person-years).
Conclusions and Relevance: Given the high burden of STIs among individuals initiating PrEP as well as persistent users of PrEP, this study highlights the need for active integration of HIV and STI services for an at-risk and underserved population.
Jason J Ong; Rachel C Baggaley; Teodora E Wi; Joseph D Tucker; Hongyun Fu; M Kumi Smith; Sabrina Rafael; Vanessa Anglade; Jane Falconer; Richard Ofori-Asenso; Fern Terris-Prestholt; Ioannis Hodges Mameletzis; Philippe Mayaud