Scientists discover new complications in immunocompromised people

A ‘terrifying’ form of smallpox affects people with advanced HIV, scientists say. The form of the virus, formerly known as monkeypox, is about 15% fatal in immunocompromised people.

A severe and “terrifying” form of smallpox has been identified in immunocompromised people living with HIV, which appears to be fatal in about 15% of cases.

Solid organ transplant recipients and those with blood cancers may also be at risk, according to The Guardian, although no cases have yet been identified in such people.

Scientists are urging people at high risk of contracting HIV to get tested for the virus, as well as anyone who tests positive for smallpox, formerly known as monkeypox.

They also would like to see smallpox added to the World Health Organization’s list of serious infections that are especially dangerous for people with advanced HIV, which could provide more financial and medical support for those at risk.

Since May 2022, about 85,000 smallpox cases and 93 deaths have been reported in 110 countries around the world. Many of these cases were in intimate male contacts, and 38-50% of those diagnosed with smallpox are also living with HIV – the vast majority of them are on HIV treatment and lead healthy lives.

In response to reports of particularly severe cases of smallpox in HIV patients, Professor Chloe Orkin of Queen Mary University of London and the Barts Health NHS trust and colleagues studied 382 cases of people with advanced HIV infection and smallpox, including 27 who died from smallpox during the current outbreak.

“The virus seems to behave very differently in these people,” says Professor Orkin, whose results are published in The Lancet. “Usually the disease affects the area around the site of entry, but in this case it spreads throughout the body and causes these massive, destructive, ulcerative skin lesions. It also causes lung disease. It’s horrible”.

Based on current data, this form of the disease appears to kill 15% of people with advanced HIV and immunosuppression – although the figure could be as high as 27% in those with the lowest CD4 cell count (a marker of how weakened the HIV immune system is).

Not all people with HIV are at risk of contracting this type of smallpox. Those on antiretroviral treatment for HIV and who have normal CD4 counts appear to experience the same symptoms and the same prognosis if they contract smallpox as those who do not have HIV. “It’s a nasty disease – I wouldn’t wish it on anyone – but it’s self-limiting,” notes Professor Chloe Orkin.

However, people whose CD4 count falls below 200 cells/mm3 are at risk. This may include people living with undiagnosed HIV, since symptoms often do not appear until the CD4 count falls below a critical level.

“Everyone with smallpox should get tested for HIV, and if someone has HIV and gets smallpox, their CD4 status needs to be measured,” says Orkin. She also urged those who have been putting off learning their HIV status to get tested. “Everything has changed. We have a disease that is now circulating in people at low levels, which is potentially fatal for people with HIV, and they die within a month.”

Health authorities should also prioritize ensuring that people living with HIV receive both doses of smallpox vaccine, especially in countries with low diagnosis rates or without universal free access to antiretroviral treatment, says Prof. Oriol Mithia of Trias and Puyol University Hospital in Barcelona, ​​lead author of the study.