Study shows HIV status does not change treatment outcome for mpox

mpox virus

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HIV status did not affect treatment outcomes in mpox patients treated with the antiviral tecovirimat (Tpoxx), according to findings published today in the Annals of Internal Medicine.

The study, conducted by researchers from Columbia University Medical Center and NewYork Presbyterian Hospital, included 196 people treated with tecovirimat in New York City from June 20 to August 29, 2022, during the height of the mpox outbreak in the United States. Of 154 patients who tested positive for mpox, 72 were also HIV-positive, 82 were HIV-negative, 134 completed at least 1 follow-up visit, and 88 completed a posttreatment follow-up.

The global mpox outbreak of 2022 was defined by cases among men who have sex with men (MSM), as the virus was spread primarily through close sexual contact. Various studies on the outbreak have shown that people with HIV have been disproportionately affected in the outbreak and represent between 35% and 47% of mpox cases.

How much of a role HIV status has on mpox progression and as an independent risk factor for contracting the virus is unknown; however, some studies have shown that people with HIV may be more likely to experience severe mpox or require hospitalization.

Symptoms differed slightly among groups

Last summer, the US Centers for Disease Control and Prevention (CDC) said patients at risk for developing severe mpox could be treated with the smallpox antiviral Tpoxx.

All patients treated with Tpoxx in the study were born male, and all but two were MSM. Rates of coincident sexually transmitted infection at the time of mpox diagnosis were greater among patients without HIV (38% vs. 26%). Patients who had HIV were slightly older (average, 39 vs 32 years) than those who were HIV negative and more likely to be Black or Hispanic.

Symptom presentation also varied slightly between the two groups: People with HIV were more likely to report skin lesions, fever, and diarrhea on day 1 of illness, whereas those without HIV were more likely to experience a prodrome and to develop additional symptoms or examination findings, including lymphadenopathy, the authors said.

The time from symptom onset to treatment initiation with Tpoxx was shorter in people with HIV (7.5 vs 10 days), but in both groups the most common indication for Tpoxx treatment was proctitis.

Only four patients in the study had serious adverse side effects while taking Tpoxx, but investigators said the events were unlikely to be related to tecovirimat. For almost all participants, Tpoxx was safe, with few side effects reported.

Most patients were pain-free at the end of the treatment period…Rates of persistent symptoms did not vary by HIV status.

Treatment outcomes were largely the same for both HIV-positive and -negative patients.

"People with HIV infection started treatment 3 days sooner than HIV-negative patients, but both groups reported improvement with similar rapidity," the authors wrote. "Most patients were pain-free at the end of the treatment period…Rates of persistent symptoms did not vary by HIV status."

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