Sunday, March 14, 2021

Vaginal inserts for prevention of sexually transmitted infections

 

In this Cochrane Review we assessed the effects of topical microbicides (chemical substances that can be applied inside the vagina or rectum), compared to placebo (inactive substance), to prevent women who have sex with men and men who have sex with men from getting sexually-transmitted infections (STIs), including HIV.

Background

This is an updated version of our Cochrane Review published in 2012. Both curable and incurable STIs continue to rise, despite the prevention strategies implemented to date. Women often have the highest rates of STIs and account for a disproportionate number of new infections. STIs are often without symptoms. Despite their greater vulnerability, current options to reduce the spread of STI remain limited for women. There is thus a clear need for new and effective strategies to prevent people from getting STIs, including HIV.

Trial characteristics

Cochrane researchers searched the available literature up to August 2020 and included 12 trials with 32,464 women who have sex with men. The trials included seven types of inserts (six vaginal gels and one vaginal ring) that were compared with placebo, all conducted among women aged over 16 years. All trials were conducted in sub-Saharan Africa, with one having a study site in India and another having a site in the USA. The Cochrane researchers did not find any studies that were conducted among men who have sex with men.

Key results

Compared with placebo, the rate of HIV infection was lower in the group that took vaginal inserts containing the antiretroviral drug known as dapivirine, but other STIs occurred at similar rates in dapivirine and placebo groups. Tenofovir gel may also reduce the rates of herpes simplex virus infection, but not other STIs. In addition, the cellulose sulphate gel resulted in lower rates of chlamydia infection, compared to placebo. When other microbicide gels were compared with placebo, could be little or no difference in the rates of STI. None of the trials reported fungal STI as outcome.

Compared with placebo, the rate of HIV infection was lower in the group that took vaginal inserts containing the antiretroviral drug known as dapivirine, but other STIs occurred at similar rates in dapivirine and placebo groups. Tenofovir gel probably reduces the rates of herpes simplex virus infection, but not other STIs. Cellulose sulphate gel probably results in lower rates of chlamydia infection, compared to placebo. When other microbicide gels were compared with placebo, could be, there is little or no difference in the rates of STI. None of the trials reported fungal STI as outcome.

Certainty of evidence

The certainty of evidence was low for most outcomes reported in this review, due to heterogeneity and small number of studies and participants for certain microbicides. This led to imprecision of the findings (ranging from large clinical benefits to substantial harm).

How up-to-date is this review?

The review authors searched for studies that were published up to August 2020.

Authors' conclusions: 

Current evidence shows that vaginal dapivirine microbicide probably reduces HIV acquisition in women who have sex with men. Other types of vaginal microbicides have not shown evidence of an effect on acquisition of STIs, including HIV. Further research should continue on the development and testing of new microbicides.