bacterial sexually transmitted infections

Postexposure Prophylaxis with Doxycycline Lowered Incidence of Bacterial Sexually Transmitted Infections

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In an open-label randomized trial, postexposure doxycycline significantly reduced bacterial STI incidence in at-risk MSM and transgender women who were on PrEP or were living with HIV.

With the rising incidence of bacterial sexually transmitted infections (STIs) in many countries, particularly among men who have sex with men (MSM) and transgender women, better interventions are needed. Postexposure prophylaxis (PEP) with doxycycline (DOXY) after condomless sex was shown to be beneficial against syphilis and chlamydia but not gonorrhea in a study conducted in France (NEJM JW Infect Dis Jan 2 2018 and Lancet Inf Dis 2017 Dec 8; [e-pub]). Now, researchers have evaluated the same strategy in MSM or transgender women who were on preexposure prophylaxis (PrEP) or were living with HIV (PLWH) in the U.S. In all, 501 participants (327 [PrEP group] and 174 [PLWH group]) were randomized to a single 200-mg dose of DOXY PEP or standard of care (SOC) without DOXY. The primary endpoint was diagnosis of a new bacterial STI per follow-up quarter.

Within the PrEP group, an STI was diagnosed in 61 of 570 quarterly visits (11%) for those receiving DOXY versus 82 of 257 visits (32%) for SOC. A significant 66% reduction was seen for the three STIs, including a 55% reduction in gonorrhea incidence. For the PLWH group, a new STI was diagnosed in 36 of 305 quarterly visits (12%) in the DOXY arm compared with 39 of 128 visits (30%) in the SOC arm. The reduction in new STI diagnoses for the PLWH group was 62% (also significant) for those receiving DOXY, including a 57% reduction in new gonorrhea diagnoses. DOXY resistance was seen in 4 of 15 gonorrhea cases (27%) at baseline and 5 of 14 cases (38%) in the DOXY group versus 2 of 16 (12%) in the SOC group. The investigators concluded that DOXY PEP represents an effective strategy for reducing bacterial STIs in this high-risk population.

Comment

Two studies presented at the 2023 Conference on Retroviruses and Opportunistic Infections also examined DOXY PEP. The ANRS DOXYVAC Study was stopped early after a 65% reduction in bacterial STIs was noted in the DOXY group and a benefit of the 4CMenB vaccine (50% reduction in new gonorrhea infection) was seen. In another study involving women on PrEP in Kenya, DOXY PEP was not effective for unclear reasons. Taken together, these studies support the use of DOXY PEP for at-risk MSM and transgender women but not at this time for cisgender women. Ongoing monitoring for trends in gonorrhea resistance as well as further confirmation of the 4CMenB vaccine’s benefits are warranted.

Postexposure Prophylaxis with Doxycycline Lowered Incidence of Bacterial Sexually Transmitted Infections

Posted by

0


In an open-label randomized trial, postexposure doxycycline significantly reduced bacterial STI incidence in at-risk MSM and transgender women who were on PrEP or were living with HIV.

With the rising incidence of bacterial sexually transmitted infections (STIs) in many countries, particularly among men who have sex with men (MSM) and transgender women, better interventions are needed. Postexposure prophylaxis (PEP) with doxycycline (DOXY) after condomless sex was shown to be beneficial against syphilis and chlamydia but not gonorrhea in a study conducted in France (NEJM JW Infect Dis Jan 2 2018 and Lancet Inf Dis 2017 Dec 8; [e-pub]). Now, researchers have evaluated the same strategy in MSM or transgender women who were on preexposure prophylaxis (PrEP) or were living with HIV (PLWH) in the U.S. In all, 501 participants (327 [PrEP group] and 174 [PLWH group]) were randomized to a single 200-mg dose of DOXY PEP or standard of care (SOC) without DOXY. The primary endpoint was diagnosis of a new bacterial STI per follow-up quarter.

Within the PrEP group, an STI was diagnosed in 61 of 570 quarterly visits (11%) for those receiving DOXY versus 82 of 257 visits (32%) for SOC. A significant 66% reduction was seen for the three STIs, including a 55% reduction in gonorrhea incidence. For the PLWH group, a new STI was diagnosed in 36 of 305 quarterly visits (12%) in the DOXY arm compared with 39 of 128 visits (30%) in the SOC arm. The reduction in new STI diagnoses for the PLWH group was 62% (also significant) for those receiving DOXY, including a 57% reduction in new gonorrhea diagnoses. DOXY resistance was seen in 4 of 15 gonorrhea cases (27%) at baseline and 5 of 14 cases (38%) in the DOXY group versus 2 of 16 (12%) in the SOC group. The investigators concluded that DOXY PEP represents an effective strategy for reducing bacterial STIs in this high-risk population.

Comment

Two studies presented at the 2023 Conference on Retroviruses and Opportunistic Infections also examined DOXY PEP. The ANRS DOXYVAC Study was stopped early after a 65% reduction in bacterial STIs was noted in the DOXY group and a benefit of the 4CMenB vaccine (50% reduction in new gonorrhea infection) was seen. In another study involving women on PrEP in Kenya, DOXY PEP was not effective for unclear reasons. Taken together, these studies support the use of DOXY PEP for at-risk MSM and transgender women but not at this time for cisgender women. Ongoing monitoring for trends in gonorrhea resistance as well as further confirmation of the 4CMenB vaccine’s benefits are warranted.