Researchers identify ‘necrotizing’ form of monkeypox

An international team of scientists has discovered a “necrotizing” form of monkeypox that preys on men with advanced HIV and has a mortality rate of 15%. While monkeypox typically leads to a few mild vesicles that clear up in a few weeks, the aggressive form of the disease causes skin ulcers that continue to grow and even spread to the lungs, eyes and intestines, says Oriol Mitjà, the lead author of the study, which was published Tuesday in The Lancet. “Some of these guys asked to be sedated because they said they couldn’t take the pain anymore. The lesions are equivalent to those of a major burn,” says Mitjà, who is a doctor at the Germans Trias i Pujol Hospital in Barcelona.

Since the current monkeypox outbreak began in May 2022, some 85,000 cases have been reported worldwide, the vast majority in gay and bisexual men (98%, according to a study of 500 cases in 15 countries). The main route of transmission is close physical contact during sexual intercourse. The population groups most at risk, explains Mitjà, are men living with HIV and patients who take daily antiretroviral drugs – known as pre-exposure prophylaxis (PrEP) – to avoid HIV infections during unprotected sex.

In November, the World Health Organization (WHO) decided to change the name of the disease to mpox on the grounds that the name monkeypox was “discriminatory and stigmatizing.” Both names will be used simultaneously for one year while monkeypox is phased out. The disease has been known as monkeypox since it was discovered in Asian macaques in a scientific laboratory in Denmark more than half a century ago. The first known human case was detected in a child from the Democratic Republic of the Congo in 1970.

Almost half of the 85,000 mpox patients reported last year were also living with HIV, the virus that causes AIDS. If not treated with antiretroviral drugs, HIV destroys CD4 lymphocytes, a type of white blood cell that protects people against infection. The necrotizing cases of monkeypox described in The Lancet were concentrated in men with CD4 counts of less than 200 cells per cubic millimeter, indicating very advanced HIV. With the defenses weakened by HIV, the mpox virus is unstoppable. “We don’t call it necrotizing because of its speed, but because it doesn’t stop. It goes on and on and on. No matter how many actions you take, the virus continues to progress,” warns Mitjà.

In the study, the researchers analyzed 382 cases of monkeypox in people with advanced HIV. The data included 367 cisgender men, four cisgender women and 10 transgender women, with a median age of 35. The heart-wrenching photographs included in the investigation show men covered with necrotizing skin lesions, particularly around the mouth, genitals and anus. This aggressive form of the virus is not a new variant, but rather shows how the pathogen can cause more severe illness in people living with HIV. The study analyzed 27 of the 60 known monkeypox deaths last year, finding that all 27 victims had very low defenses.

“Many of these guys were not treated with antiretrovirals against HIV. Many are from Latin America, where there is no universal access to these drugs. And others were not even diagnosed,” says Mitjà. Most (73%) of the patients included in the study received treatment in Argentina, Brazil, Canada, Chile, Ecuador, Mexico, Peru and the United States. The rest were treated in a dozen European countries, while another six patients received treatment in Nigeria. Nine percent did not know they had HIV. Of those who knew, one in three were not taking antiretroviral drugs to prevent AIDS.

The authors of the study are urging the WHO to add the necrotizing form of mpox to the list of AIDS-defining illnesses, which includes 14 infections that operate differently and more dangerously in people with advanced HIV. British doctor Chloe Orkin, co-lead author of the research, is calling for greater vigilance: “Everyone with mpox should be tested for HIV. And everyone with HIV and mpox should take a test to measure their defenses.”

More than 100 of the 382 individuals analyzed in the study had to be hospitalized. In the case of the 27 patients who died, the average time spent in hospital was 47 days. According to Orkin, this aggressive form of monkeypox killed 30% of individuals with HIV who had very low defenses: CD4 cell counts of less than 100 cells per cubic millimeter. Based on the results, Orkin is calling for people living with HIV to receive priority access to monkeypox vaccines and antiviral treatments. “It is imperative that vaccines and antivirals are accessible throughout the world and for this greater global cooperation is necessary,” says Orkin, who is a consultant physician at Queen Mary University of London.

Doctor Meg Doherty, director of Global HIV, Hepatitis and STI Programs at the WHO, told EL PAÍS that the organization is going to consider including the necrotizing form of monkeypox in its criteria to diagnose advanced HIV. “This recent case series makes a very compelling argument that people living with HIV, and with a CD4 count below 200 cells per cubic millimeter, are at high risk of severe disease and death from mpox, and that the disseminated infection behaves like other opportunistic infections,” says Dohert, who wants to guarantee treatments, vaccines and diagnostic tests for the people who need them most.

At the Germans Trias i Pujol Hospital in Barcelona, Mitjà has seen 250 cases of mpox, but only three in people with advanced HIV and low defenses. Of these three, one paitent had very serious complications. Mitjà regrets that treatment is not available globally: “There are many countries where there is still no free or easy access to antiretrovirals against HIV, such as the United States and Mexico. Regarding mpox antivirals, they are only available in first world countries. There are no antivirals for mpox in any Latin American country.”

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