of advantage of doxycycline Post-exposure prophylaxis (Doxy PEP) to prevent transmission of sexually transmitted infections (STIs) in men and trans women appears to fall short of cisgender women, who have disproportionately high rates of infection in many regions.
“This was the first trial to evaluate doxycycline PEP in cisgender women,” said lead author Jenell Stewart, Ph.D., of the University of Minnesota, Minneapolis, at the Conference on Retroviruses and Opportunistic Infections (CROI) 2023. Next general meeting.
“Unfortunately, our primary results were not statistically significant — we found no reduction in STDs among cisgender women. [reported effects] between cisgender men and transgender women,” she said.
The findings are from a study of 449 non-pregnant cisgender women (mean age 24 years) who were orally ingested daily in Kenya. HIV Pre-exposure prophylaxis (PrEP) for a median of approximately 7 months.
Women were randomized to receive either Doxy PEP 200 mg taken within 72 hours of intercourse (n = 224) or standard treatment including quarterly screening and treatment for STIs (n = 225). was given.
Among women, 36.7% reported transactional sex at enrollment. The baseline prevalence of sexually transmitted diseases was 17.9%, including chlamydia 14.1%, gonorrhea 3.8%, 0.4%. syphilisThere were no differences between the study groups.
In a survey, 78% of women reported compliance with Doxy PEP use. They took prophylaxis for at least as many days as they had sex.
Nevertheless, at quarterly visits that included genital STI testing, there was no significant difference in the incidence of STIs between groups, with 50 patients in the Doxy PEP group and 59 in the standard screening group developing an STI. did (relative risk 0.88; P. = .51).
Of the infections, 85 had chlamydia, 35 in the Doxy PEP group, 50 with standard care, and 31 with gonorrhea, of which 19 in the Doxy PEP group and 12 with standard care. . Eight had both infections and one had syphilis.
Results were consistent across sub-analyses of patients grouped according to STI, pregnant patients (n = 80), or patients classified by other factors, including age. contraception Baseline use, transactional sex, STI.
None of the women developed HIV and there were no serious events related to Doxy PEP treatment.
Cisgender women bear the ‘heaviest burden’ of STDs
The Centers for Disease Control and Prevention (CDC) reports that women bear the long-term effects of sexually transmitted infections disproportionately, and given the high rate of sexually transmitted infections among cisgender women, this study The results are disappointing.
“For example, every year, untreated STDs cause infertility At least 20,000 women in the United States have been infected, and if left untested and untreated, pregnant women are very likely to pass syphilis to their unborn children,” the CDC said. . report.
The incidence of sexually transmitted infections is particularly high among women who take it. HIV prep In regions like East Africa, the rate of STDs among cisgender women is often higher than among men taking PrEP in high-income countries, Stewart said.
Previous studies of Doxy PEP in men and transgender women taking HIV PrEP include: new research These studies, presented at CROI, showed very promising reductions in STIs with rates of up to about 80% in chlamydia and syphilis.
Attachment, Anatomy, Resistance
Leading theories for lack of infection prevention among cisgender women surround issues of resistance as well as anatomy and compliance, Stewart said.
Regarding bacterial resistance, initial testing on a limited number of samples found no evidence of markers of resistance to chlamydia, but all gonorrhea samples showed tetracycline resistance. Gonorrhea at baseline and follow-up in both groups.
As for anatomical differences, Stewart noted that doxycycline may not prevent sexually transmitted infections in the cervical tissue of cisgender women. Women are known to be at higher risk of infection due to the ease with which the virus can enter.
This study was designed to optimize adherence to Doxy PEP. Measures included monitoring with weekly text message surveys, and women reported high adherence rates.
Overall retention in this study was high. 97% of quarterly follow-up visits were completed, including 95% in the Doxy PEP group and 98% in the standard care group.Weekly survey response rate was 81%
Notably, women reported ‘incomplete’ use of treatment, suggesting societal issues such as stigma against the use of prophylaxis.
The results highlight the need for continued efforts to ensure that no group of patients is left behind as the intervention progresses, Stewart said.
“The burden of sexually transmitted infections for cisgender women is large and growing,” she concluded. “STI prevention interventions are needed.”
Commenting on the study, Renee A. Heffron, Ph.D., M.P.H., said the findings were “somewhat surprising because the results of trials in other populations were positive.
“But cisgender women are exposed through the cervix, and this tissue is different than the tissue in the rectum or urethra,” said Heffron, a professor of medicine and director of the Center for AIDS Research at the University of Alabama, Heersink School of Medicine. Medicine says.birmingham said Medscape Medical News.
Additional findings from this study should help shed light on the important issues of compliance and drug concentration levels in cervical tissue, she added.
“For cisgender women, these data are the first and the beginning to understand whether this is a viable strategy,” Heffron said.
“We need to learn more to better understand the results from the trial’s main results, and whether there are fine-tuning to this strategy that would improve efficacy.”
The authors and Heffron do not disclose any relevant financial relationships.
Conference on Retroviruses and Opportunistic Infections (CROI) 2023 Annual Meeting: Abstract 121. Presented February 20, 2022.
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