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Mexico reports surge in human screwworm cases in 2026
Screwworm infestations in humans have seen a significant surge in Mexico, with cases quintupling in 2026. According to the Special Epidemiological Surveillance System for Miasis by Cochliomyia Hominivorax, there have been 575 human cases recorded so far in 2026, compared to 117 in 2025. Since the first human case was identified in April 2025, the country has accumulated a total of 692 human infections across 27 states.
Chiapas has been identified as the most affected state with 165 cases, followed by Veracruz with 116 and Oaxaca with 68. The outbreak has also resulted in four deaths in 2026, occurring in the states of Oaxaca, Querétaro, Veracruz, and Yucatán. The disease, known as myiasis, is caused by the larvae of the Cochliomyia hominivorax fly, which feed on the skin and tissues of warm-blooded animals and humans.
In addition to human cases, the pest is heavily impacting livestock. In Campeche, Senasica has reported 1,100 cases of myiasis in cattle, horses, dogs, and wildlife. In Sonora, 69 active cases have been reported across 11 municipalities, including Hermosillo. To combat the spread, a sterile fly production plant in Chiapas is currently operating at 60 to 70 percent capacity to release insects and control the population.
Entities
Castilla-La Mancha · Chiapas · Ecosur · Mexico · Museo del Desierto · Oaxaca · Senasica · Toledo · UNAM · Veracruz
Claims
What the coverage asserts, and how many sources carry each claim.
- [● 2 SOURCES] The infestation has spread to 27 Mexican states. lineadirectaportal.com · ncscampeche.com
- [○ 1 SOURCE] Campeche has recorded 1,100 cases of myiasis in livestock and wildlife. www.poresto.com
- [● 2 SOURCES] Mexico has recorded 692 total cases of screwworm infestation in humans since April 2025. lineadirectaportal.com · ncscampeche.com
- [● 3 SOURCES] Four deaths related to screwworm infestation occurred in 2026 in Oaxaca, Querétaro, Veracruz, and Yucatán. closeup.mx · lineadirectaportal.com · ncscampeche.com
- [● 3 SOURCES] There were 575 human cases of screwworm reported in 2026 through September 18. closeup.mx · lineadirectaportal.com · ncscampeche.com
- [○ 1 SOURCE] Sonora has 69 active cases of screwworm across 11 municipalities, including Hermosillo. www.yucatan.com.mx
- [○ 1 SOURCE] A sterile fly production plant in Chiapas is operating at 60 to 70 percent capacity to combat the pest. www.poresto.com
- [● 3 SOURCES] Chiapas is the state with the highest number of cases, totaling 165. closeup.mx · lineadirectaportal.com · ncscampeche.com