Prolonged mpox cases more likely to occur in Black and HIV patients, study suggests
September 15, 2025
A new California study highlights troubling disparities in mpox outcomes, showing that Black patients and people with HIV were more likely to experience prolonged infections lasting 28 days or more. Published in Emerging Infectious Diseases, the analysis found that protracted cases carried higher hospitalization rates, especially among those with lower CD4 counts or not engaged in HIV care. Notably, no prolonged cases occurred in fully vaccinated patients. These findings emphasize the urgent need for targeted vaccination campaigns, education, and outreach to vulnerable groups. Addressing inequities in care and prevention remains essential to reducing the burden and risks of mpox.
Recent research from California underscores critical disparities in mpox outcomes, particularly among Black patients and people living with HIV. The study, published in Emerging Infectious Diseases, analyzed more than 6,400 mpox infections reported between May 2022 and August 2024. While the typical duration of infection ranges from 14 to 28 days, 82 cases, or 1.3 percent, were considered prolonged, lasting 28 days or longer.
Prolonged infections were significantly more severe. Hospitalization was required in 25.6 percent of these patients, compared with only 4.5 percent of those with shorter illnesses. Alarmingly, the longest infection stretched to 345 days, with more than one-quarter of prolonged cases lasting 50 days or more. Disproportionate impacts were evident: 20.7 percent of prolonged cases were among Black patients, compared with 11.6 percent of non-prolonged cases, while 61 percent of patients with extended illness were living with HIV.
The findings further revealed that individuals with HIV and lower CD4 counts or those not engaged in HIV care faced greater risk of extended disease. In contrast, no prolonged cases were recorded among fully vaccinated individuals, highlighting the strong protective effect of the two-dose Jynneos vaccine.
These results have profound implications for public health policy. Prolonged mpox cases not only heighten risks of hospitalization and severe outcomes but also extend infectious periods, potentially allowing more opportunities for viral mutation. Researchers stress that communities disproportionately affected — including Black patients and those with HIV — should be prioritized in vaccine education, outreach, and access efforts.
The study reinforces the urgent need for equity-driven interventions. Expanding vaccine coverage, bolstering HIV care engagement, and addressing racial disparities in health outcomes are all vital to reducing mpox’s impact. Protecting vulnerable populations is not only a matter of fairness but a cornerstone of outbreak prevention and control.