December 11, 2019
2 min read

Study finds high rates of STIs among new and persistent PrEP users

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Jason J. Ong, PhD, MBBS
Jason J. Ong

Almost one-quarter of patients who initiate pre-exposure prophylaxis, or PrEP, for HIV prevention have at least one STI, and nearly three-quarters of those who continue to use it are diagnosed with chlamydia, gonorrhea or syphilis within 1 year of using it, according to results from a systematic review and meta-analysis published in JAMA Network Open.

“HIV PrEP is being rolled out globally. This will protect many people from HIV. However, PrEP does not protect against other sexually transmitted infections,” Jason J. Ong, PhD, MBBS, associate professor in the Department of Clinical Research at the London School of Hygiene & Tropical Medicine, told Healio. “We wanted to quantify how much STIs are in PrEP users as a means to advocate to strengthen sexual health services in these settings where PrEP is being offered.”

Ong and colleagues searched nine databases for studies reporting STI prevalence and incidence among PrEP users through Nov. 20, 2018. They included 88 articles with data from 26 countries in the analysis. Most studies — 70% — were conducted in high-income countries, and 66% were from programs only for men who have sex with men.

According to the study data, the pooled prevalence of chlamydia, gonorrhea and early syphilis was 23.9% (95% CI, 18.6%-29.6%) before starting PrEP, with the highest prevalence in the anorectum, compared with genital sites and oropharyngeal sites, Ong and colleagues reported. Ong said the findings suggested that PrEP programs are targeting the right people — those at “high risk for both HIV and STIs.”

“This high STI rate did not reduce over time. PrEP users continued to stay at risk for STIs, suggesting the need for ongoing sexual health services among PrEP users,” he said.

According to the review, the pooled incidence of studies reporting the composite outcome of chlamydia, gonorrhea and early syphilis among people continuing to use PrEP was 72.2 per 100 person years (95% CI, 60.5-86.2 per 100 person years).

“Our findings underscore the lost opportunities if STI services are not provided for individuals using PrEP and highlight the opportunity to harness the growing interest in providing PrEP programs globally to be a gateway to provide more comprehensive sexual and reproductive health services for all PrEP users,” Ong said.

In an accompanying comment, Roger Chou, MD, a professor of medicine at Oregon Health and Science University, agreed that the findings showed the importance of prevention, screening and monitoring as part of a strategy for STI control in people initiating PrEP.

“Rather than viewing PrEP as a trade-off between prevention of HIV and prevention of other STIs, initiation of PrEP should be considered a prime opportunity for reducing the burden of STIs in this high-risk population,” Chou wrote. “This issue is of particular importance in the current era of drug-resistant STIs.”

Chou said more research is needed to define optimal STI screening and monitoring practices, including which sites to test and at what intervals.

“In the meantime, evidence indicates poor adherence to existing recommendations on STI screening and monitoring. Scale-up and implementation of PrEP should prioritize efforts to address this important practice gap,” he said.– by Caitlyn Stulpin

Disclosures: Chou reports receiving funding from the Agency for Healthcare Research and Quality to conduct research on PrEP. Ong reports receiving a research grant from WHO. Please see the study for all other authors’ relevant financial disclosures.