Cases of flesh-eating screwworm on the rise in Mexico

August 28, 2025

Mexico is experiencing a significant 53% increase in New World screwworm (NWS) infestations in animals over a four-week period ending mid-August, according to government data. The flesh-eating parasite primarily affects cattle but has also been found in other animals and humans, with dozens of people receiving treatment in southern Mexican states. This surge coincides with the first confirmed human case in the United States from a patient returning from El Salvador, marking a concerning northern spread of the parasite that was previously eradicated in the US in 1966 and Mexico in 1991.

Who is affected

Cattle and other animals (dogs, horses, sheep)
Dozens of people in Campeche and Chiapas states in southern Mexico
An 86-year-old woman who died in Campeche state in July
People working with livestock or living in rural areas with infested livestock
Individuals with pre-existing health issues and the elderly
A patient who returned to the US from El Salvador

What action is being taken

Mexican officials are registering cases across different animal species and humans
Hospitals in southern Mexican states are treating dozens of people for infestations
US health authorities are confirming and monitoring cases
The US Centers for Disease Control and Prevention is urging people who visited affected regions to watch for symptoms

Why it matters

The parasite can cause serious damage and even death as larvae tear into living tissue
This represents a resurgence of a parasite previously eradicated in the US and Mexico
The 53% increase in affected animals in just four weeks indicates rapid spread
The parasite is moving northward from its typical range in Central and South America
Even though human fatalities are rare, certain populations face higher risks

What's next

No explicit next steps stated in the article

Read full article from source: BBC