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HIV-positive people at higher risk for severe MPX, San Francisco officials say

Signs depict syringes, scissors and TPOXX, a pill being used to treat MPX, lays flat at a protest outside the San Francisco Federal Building on Aug. 8, 2022. | Benjamin Fanjoy for The Standard

Immune-compromised individuals—and especially those with undiagnosed or advanced HIV—are more susceptible to contracting a severe, deadlier and “horrific” form of MPX, new research studies and the SF Department of Public Health findings suggest. 

Researchers in England and Spain have found that people with HIV had worse clinical outcomes and higher mortality rates due to MPX or Mpox, formerly known as monkeypox. Of the estimated 85,000 cases of MPX that have been reported since May 2022, roughly 38%-50% of those diagnosed also have HIV. 

That global trend was also true in San Francisco, which counted 845 total cases of MPX as of Feb. 22. The majority of those cases were first diagnosed in summer 2022. 

“People living with HIV were disproportionately impacted by Mpox throughout the 2022 global Mpox outbreak,” an SF health department spokesperson said. “This trend was observed in Europe, nationally, as well as in San Francisco, where approximately 35% of people diagnosed with Mpox are living with HIV. In addition, people living with HIV who are immunosuppressed who acquired Mpox had more severe disease and were more likely to be hospitalized.” 

MPX is a serious disease that causes flu-like symptoms and a distinct rash of painful sores and lesions that look like blisters or scabs. 

READ MORE: MPX Victims on Agonizing Waits for Treatment as They Fight Red Tape

For individuals with undiagnosed or advanced HIV, researchers found that contracting Mpox can cause worse skin lesions and blisters, lung disease and other severe complications. 

This severe form of MPX has an estimated mortality rate of at least 15% for the immunosuppressed, though researchers warn that the actual mortality rate could hit 27% in those with the most advanced forms of HIV. 

Not all individuals with HIV will contract the more severe form of MPX, however. Those undergoing active treatment for HIV and have a healthy count of CD4 cells—markers that show how much HIV has weakened one’s immune system—may contract MPX and still receive the same prognosis as someone who doesn’t have HIV. 

The results of new MPX studies have pushed scientists to encourage more vigilant MPX testing and vaccinations for immune-compromised individuals, including those who have HIV, have received an organ transplant or have a form of blood cancer. 

In San Francisco, approximately 28,874 residents were vaccinated against MPX between May and December 2022. Over half of those vaccinated were aged between 25 and 44 years, and more than two-thirds of recipients identified as “gay, lesbian or same-sex loving.”

The health department says that it requested city clinicians to include additional MPX screening—assessing risk and vaccination status—for men, trans or nonbinary people who have sex with other men, trans or nonbinary people. The agency has also requested that MPX vaccines be included in part of a care package that handles discussing HIV treatment and prevention options, such as HIV PrEP, with patients. 

There is a very low risk of contracting MPX in San Francisco today. The city has only documented a handful of cases monthly since October 2022, down from the average 100 weekly cases the city racked up in the summertime. 

Nonetheless, MPX remains a global emergency and case counts are rising in Canada and Mexico.