People with HIV are not at greater risk for severe mpox unless they are immunosuppressed

People living with HIV are not more likely to be hospitalised with severe mpox (formerly known as monkeypox) unless they have advanced immune suppression, according to study findings presented at the 12th International AIDS Society Conference on HIV Science (IAS 2023).

“The high prevalence of HIV among mpox cases highlights the importance of HIV testing for individuals who do not know their status,” said Ana Hoxha of the World Health Organization (WHO). “For individuals with unknown HIV status, mpox testing can be an opportunity for HIV testing, prevention and care.” What’s more, she added, it’s important for clinicians to know the immune status of mpox patients in order to better prevent severe outcomes.

As aidsmap previously reported, the UK Health Security Agency (UKHSA) reported the first mpox cases in the global outbreak last May. As of 30 June, UKHSA has identified 3732 cases in the UK. Worldwide, there have been 88,600 cases as of 25 July, resulting in 152 deaths, according to WHO. Most cases outside of Africa have been among gay, bisexual and other men who have sex with men.

More than a quarter of people diagnosed with mpox in the UK and about half worldwide were living with HIV. At this year’s Conference on Retroviruses and Opportunistic Infections, Professor Chloe Orkin of Queen Mary University of London reported that mpox can be much more severe in people with HIV who have a very low CD4 T-cell count – so much so that she called for mpox to be classified as an AIDS-defining opportunistic infection.

Orkin’s findings were based on an international analysis of nearly 400 mpox cases among HIV-positive people with a CD4 count below 350. The mortality rate was 27% among those with a count below 100, but no one who was on antiretroviral therapy with well-controlled HIV died. In April, the US Centers for Disease Control and Prevention (CDC) reported that most people who died of mpox in the United States were Black gay men with AIDS.

At IAS 2023, Hoxha presented findings from a larger analysis based on global surveillance data. Among the more than 82,000 mpox cases reported to WHO between January 2022 and January 2023, about 32,000 (39%) had information on their HIV status. Of these, 52% were living with HIV.

Consistent with previous reports, most were men who have sex with men. About 80% reported that sex was their most likely route of mpox acquisition, and nearly 60% of both HIV-positive and HIV-negative people said they had been present at a “party setting with sexual contact.” People with HIV were more likely than HIV-negative people to have other concurrent sexually transmitted infections (5.5% vs 3.8%).

Among the 16,633 HIV-positive people diagnosed with mpox, nearly a quarter had immune suppression due to advanced HIV or another cause, compared with less than 1% of HIV-negative people. Fifty-eight HIV-positive people with mpox died compared to just four HIV-negative people.

HIV-positive people were more likely to be hospitalised than HIV-negative people with mpox (4.3% vs 3.0%) and they had a significantly higher risk of death (0.3% vs 0.03%). But while immunocompromised people living with HIV were about twice as likely to be hospitalised, the risk for HIV-positive people with an adequate CD4 count was similar to that of HIV-negative people without immune suppression.

Find out more: Mpox (monkeypox) and HIV

Likewise, Hoxha reported that HIV-positive and HIV-negative people without advanced immune suppression had “similar clinical presentation,” while immunocompromised people with HIV had more severe mpox manifestations, as previously observed by Orkin’s team. The most common symptoms were rash (including genital rash) and fever, reported by more than half of both HIV-positive and HIV-negative people.

Women, young children, people over age 65 and immunocompromised HIV-negative people were also more likely to be hospitalised with mpox, though cases were rare in these populations. Hoxha cautioned that the study findings may not apply to the 60% of reported cases without information about HIV status.

Findings from this large global analysis build on evidence from smaller cohort studies, helping to address the “paucity of data” on mpox outcomes in low- and middle-income countries, Professor Charles Gilks of the University of Queensland in Brisbane said at an advance media briefing. Helping to fill that gap, other research teams at the conference reported on mpox outcomes among people living with HIV in Brazil, Mexico and Peru.

In light of these findings, Hoxha’s team advised that health systems should ensure that people living with HIV know their status and are linked to care and antiretroviral treatment, which would lower their risk of severe mpox complications. Further, WHO recommends that countries should integrate mpox prevention, testing and care with existing HIV and sexually transmitted infection prevention and control programmes.