Oaxaca remains the state with the highest number of active cases of cattle screwworm (CSW) in the country, registering 168 of the 698 cases currently detected, according to the most recent report from the National Service for Agrifood Health, Safety and Quality (Senasica), as of December 29, 2025.
Just over a year after the first official report of this pest in Mexico, the health problem continues to be concentrated in states in the south and southeast of the country. After Oaxaca, the states with the most active cases are Veracruz, with 147; Yucatán, with 137; Chiapas, with 130; Guerrero, with 37; Quintana Roo, with 28; Campeche, with 19; Tabasco, with 17; and Puebla, with 11. Michoacán, Morelos, San Luis Potosí, and Tamaulipas each report one active case.
Of the total active cases in the country, 409 are in cattle, followed by 178 in dogs, 34 in horses, 32 in swine, 25 in sheep, 11 in goats, five in cats, three in humans, and one in birds, reflecting the multisectoral impact of this parasitic disease.
If we consider the cumulative records from the last 13 months, the total number of cases reaches 13,035, distributed across 16 states in the country. During this period, Chiapas leads the list of affected states with 5,350 infected animals, while Oaxaca ranks second nationally with 1,984 accumulated cases, followed by Veracruz with 1,870 and Yucatán with 1,509.
Regarding human impact, Oaxaca has registered two cases in the overall total, while Chiapas has the highest incidence with 82 reported cases, followed by Yucatán, Campeche, and Quintana Roo.
The Ministry of Agriculture and Rural Development reported that, as part of the national strategy to contain the pest, more than 2.122 billion pesos were allocated by the end of 2025 to epidemiological surveillance, treatment, inspection, trapping, and strengthening of sanitary infrastructure. Additionally, nearly 4 billion sterile flies were released for the biological control of the screwworm.
A sterile fly production plant is scheduled to begin operations in Metapa de Domínguez, Chiapas, in the first half of 2026. This joint Mexican-U.S. investment will have the capacity to produce up to 100 million insects per week.
Federal authorities warned that the screwworm is not a problem unique to Mexico, as outbreaks have been reported in Central American countries, such as Panama, since 2022. This underscores the need to maintain and strengthen sanitary control measures in states like Oaxaca, where the incidence remains the highest in the country.
Source: istmo.nvinoticias
