Mpox can have a devastating impact on people with advanced cases of HIV, causing severe lesions on the skin and genitals and killing up to 1 in 4 people with severely compromised immune systems.
This is according to the first major study of mpox in this population, which a worldwide team of authors published in The Lancet on Tuesday. The analysis included 382 people from 28 countries, all of whom were HIV-positive and had less than 350 counts of key immune cells called CD4 cells, which help prevent infections. Twenty-seven of these individuals died.
«The data is frightening for people with advanced HIV,» Dr. Chloe Orkin, an infectious disease expert at Queen Mary University of London and lead author of the study, told NBC News. «It’s really distressing.»
Orkin, who also presented his findings Tuesday at the annual Conference on Retroviruses and Opportunistic Infections in Seattle, urged that people with advanced HIV be given priority for mpox vaccination worldwide. She and her co-authors also called on the Centers for Disease Control and Prevention and the World Health Organization to designate mpox as an AIDS-defining condition when infection leads to necrosis, or tissue death, among people with HIV.
For people with HIV, a CD4 count of 500 or higher is considered healthy. If left untreated, the virus degrades the immune system and leads to advanced HIV disease, although antiretroviral treatment can restore this loss. A CD4 count below 200 triggers an AIDS diagnosis, which means that a person with HIV is at significant risk of 14 serious and life-threatening diseases. opportunistic infections.
Known as monkeypox until the WHO changed its name in November, mpox was first discovered in humans in 1970 and eventually became endemic in 11 African nations.
The first signs of the unprecedented global outbreak of mpox were identified in Great Britain in mid-May and in the United States shortly thereafter. Globally, there have been 86,000 cases of the virus and 96 deaths in 110 countries, including just over 30,000 cases and 32 deaths in the US, according to the Centers for Disease Control and Prevention. Throughout the outbreak, mpox has been transmitted overwhelmingly among gay and bisexual men, a demographic that in the US has a My dear HIV prevalence of 15%.
Mpox cases in the US, the CDC reports, peaked in early August at about 460 per day. Amid a concerted effort to vaccinate gay and bisexual men (nearly 1.2 million doses of the two-dose mpox vaccine have been administered), cases have steadily declined and less than 10 per day since the end of December.
Globally, mpox diagnoses have similarly declined, According to the WHO. However, many cases can go undetected.
Studies have found that 38% to 50% of people diagnosed with mpox were HIV positive.
The new Lancet paper complements a CDC’s smallest study published in November of 57 cases of people hospitalized with mpox, 43 of whom had untreated HIV. Because of the serious outcomes in people with AIDS, the CDC called for early antiviral treatment of mpox for this particular group.
Otherwise, most previous research on the outcomes of mpox in people with HIV had focused on people with well-treated HIV and generally healthy immune systems (antiretroviral treatment can suppress the virus to an undetectable level and allow the people live a long and healthy life). For that population, having HIV has generally not been associated with worse outcomes compared with being HIV-negative.
These studies indicated that the mpox outbreak was overwhelmingly driven by sex between men, with anal sex in particular likely being the main factor.
In the new Lancet article, researchers describe how people with advanced HIV were at high risk of a severe form of mpox in which excruciatingly painful lesions on the skin, genitals, and mucous membranes were large and widespread and they caused necrosis. Some of these people also developed unusual lung lesions and even respiratory failure. Bacterial skin and bloodstream infections were also common.
In addition to Orkin, the new study was led by Dr. Oriol Mitjà, an associate professor of infectious diseases at the Germans Trias University Hospital in Barcelona, Spain. Orkin and Mitjà each led one of the two main analyzes of people infected with mpox published in mid-summer 2022 that helped identify the contours and drivers of the outbreak.
Among the 382 people with advanced HIV in the study, there were 367 cisgender men, four cisgender women, and 10 transgender women. Two-thirds of them were taking antiretroviral treatment for HIV and half had an undetectable HIV viral load.
Of the 179 people with CD4 counts below 200, 15% died, including 27% of the 85 people with CD4 counts below 100. None of those with CD4 counts below 200 died, nor did any of the 42 people who received the mpox vaccine. including five who received it after their mpox diagnosis.
Compared with those with a CD4 count greater than 300, those with a count less than 100 were much more likely to have skin lesions leading to necrosis, impacts to the lungs, and other infections and sepsis. Those with a high HIV viral load of 10,000 or more also had more serious health outcomes; 30% of this group died.
All people with mpox, said Mitjà, «should be tested for HIV at the time of diagnosis, and if immunosuppression is detected, intensive management should be implemented to mitigate complications in this vulnerable group.»
These concerns are particularly acute, he said, in countries like the United States and Mexico, where the proportion of the population with HIV not taking antiretrovirals is higher than in other regions. According to CDC data, only about half of the 1.2 million people living with HIV in the US have a completely suppressed viral load thanks to antiretroviral treatment.
The authors of the Lancet article note that members of the study cohort may not be fully representative of people with advanced HIV and mpox globally. The cohort may have been biased towards those with more severe outcomes, because people with milder or asymptomatic cases may not have contacted healthcare systems.
Dr. Boghuma Titanji, an infectious disease specialist at Emory University who has treated many people with mpox, said: «The study provides much-needed confirmation of the patterns that physicians treating patients with mpox have seen in a smaller scale in his practice».
In a statement, Dr Meg Doherty, director of WHO’s global HIV, hepatitis and sexually transmitted infections programmes, said the Lancet article «makes a very compelling case» that mpox «behaves like other opportunistic infections». The WHO, it said, «will review relevant data with global experts to assess whether severe syphilis in people living with HIV is a marker of advanced HIV disease.»