Mexico’s flesh-eating screwworm cases top 500 in humans
▼ Summary
– Human cases of flesh-eating screwworm fly in Mexico have exceeded 500 in 2025 and 2026, according to a July surveillance report from Mexico’s Ministry of Health.
– A study in Emerging Infectious Diseases analyzed over 200 confirmed cases from April 2025 to March 2026 and found the infestation pace is increasing.
– Among the 200 confirmed cases, six deaths were reported, with at least one directly caused by the fly’s maggots.
– The New World screwworm fly lays eggs in wounds, inflamed tissue, mucous membranes, and orifices of warm-blooded creatures; maggots hatch within a day and feed on living flesh.
– The fly’s maggots are particularly devastating to livestock, though they also cause life-threatening wounds in humans and other warm-blooded species.
Since the flesh-eating screwworm fly made its unwelcome return to Mexico in 2024, the number of human infestations has climbed steadily. A recent surveillance report from Mexico’s Ministry of Health, released in July, confirms that more than 500 human cases were recorded across 2025 and 2026. Adding to those concerns, a new study published this week in the journal Emerging Infectious Diseases examined data from over 200 confirmed cases occurring between April 2025 and March 2026, revealing that the rate of infestation is accelerating.
Of the 200 confirmed cases analyzed in the study, six resulted in death. Mexican researchers noted that at least one of those fatalities was directly caused by the parasitic maggots themselves.
The New World screwworm (NWS) fly, once endemic to both Mexico and the United States, poses a serious threat to warm-blooded animals. Female flies deposit hundreds of eggs in open wounds, inflamed tissue, mucous membranes, and natural body openings. Within a day, the larvae hatch and begin aggressively consuming the host’s living tissue. While these maggots can create horrific, potentially fatal wounds in a wide range of species, including humans, the impact on livestock has been particularly severe.
(Source: Ars Technica)
