MPOX TRACKER

Two recent studies published in the CDC's Morbidity and Mortality Weekly Report have provided crucial insights into mpox transmission and the emergence of drug-resistant strains.

The first study, led by CDC researcher Anna Chard, focused on sexual practices that increase the risk of mpox transmission. Analyzing data from nearly 1,500 American men under 50 who have sex with men, the study found that those engaging in unprotected receptive anal sex were five times more likely to contract mpox compared to those who didn't practice this form of intercourse. This finding highlights a specific high-risk behavior within the demographic most affected by mpox outside of Africa.

However, the CDC team emphasized that while condoms can reduce transmission risk, they are not completely effective. Mpox can spread through rashes on other body parts and via routes such as saliva and respiratory secretions. The most effective prevention method remains vaccination with the Jynneos vaccine.

The second study, led by Crystal Gigante, another CDC investigator, reported on clusters of mpox cases in California and Illinois resistant to the first-line drug tecovirimat. This discovery is particularly concerning as not all mpox cases undergo genetic scrutiny, suggesting that the prevalence of this drug-resistant variant may be underestimated.

These studies come at a critical time, as the World Health Organization has declared a public health emergency of international concern due to the emergence of a potentially more severe mpox strain in the Democratic Republic of Congo. This new outbreak follows the 2022-2023 global outbreak that, for the first time, saw significant spread of mpox outside of Africa.

These findings underscore the evolving nature of the mpox threat and the importance of continued research, surveillance, and public health measures to combat its spread and manage treatment-resistant cases.