Mexico, US Sign Agreement to Control Cattle Screwworm

Mexico and the United States have signed an agreement to control cattle screwworm (CSW). In Mexico, cases of this pest have surpassed 3,000 in southern states, with economic losses reaching US$30 million per month.

Julio Berdagué, Minister of Agriculture and Rural Development (SADER), and Brooke Rollins,  Minister of the United States Department of Agriculture (USDA), signed on Friday the APHIS-SENASICA Action Plan for the Control of Cattle Screwworm. “We continue to hold dialogue and build agreements with the US government to combat and eradicate CSW. Today we approved a strengthened action plan, jointly developed by Mexican and US specialists,” Berdagué stated on his X account.

The approved plan was developed by specialists from Mexico’s National Service for Agri-Food Health, Safety and Quality (SENASICA) and the US Animal and Plant Health Inspection Service (APHIS), during joint workshops held in Mexico City at the end of July.

The strategy includes a set of measures, including the regionalization of Mexico’s territory, a protocol for the safe importation of livestock by sea, the adoption of a monitoring strategy based on fly-attractant traps, and the requirement that livestock movements within Mexico may only occur from pens certified by SENASICA to others with the same certification.

Regarding this last measure, Jalisco established the first certified handling pen for cattle inspection. This will allow authorities to control the transfer of animals between southern Mexico, the most affected region, and the northern region, which is a priority for US cattle exports.

“The new SENASICA protocol requires us to have a handling pen where the cattle arrive, are inspected by our canine units and an accredited veterinarian, and if everything is in order, a certificate confirming the cattle are free of screwworm is issued, allowing them to continue their route north,” explained Ron Ramos, Head, SADER Jalisco, in an interview with El Economista.

During the signing of the document, Berdagué emphasized that the Action Plan represents an achievement that reflects the level of collaboration between the two countries. He also stressed that, for the first time, there is a formal document establishing objectives, goals, actions, budgets, and technical protocols on key issues such as controlling cattle movement, monitoring the pest’s spread, regulating imports and cattle movements from Central America to Mexico, surveillance of domestic animals and wildlife, and outlining guidelines for potential future suspensions.

The plan also involved the participation of the Ministry of Environment and Natural Resources (SEMARNAT), particularly regarding the monitoring of cases that may occur in wildlife. Additionally, the agreement formalized US funding for the construction of a new facility in Chiapas. The plant will produce 100 million sterile flies per week. Construction began on July 4, and the facility is expected to begin operations in the first half of next year.

According to a report by SENASICA, as of July 15, 2025, the CSW outbreak has 3,324 confirmed cases, 2,738 in cattle. The most affected states, in order of severity, are: Chiapas with 2,074 cases, Tabasco with 567, Campeche with 313, Oaxaca with 152, Veracruz with 80, and Yucatan and Quintana Roo with 69 each.

Enrique López, Director General, Mexican Association of Cattle Feeders (AMEG), noted that expenses related to complying with sanitary regulations and measures to contain the spread of screwworm in southeastern Mexico amount to US$400 million.

He emphasized that the overregulation of livestock movement to contain the pest is causing losses of up to 18%, which are reflected in animal production costs. Moreover, he stated that northern Mexico has the necessary conditions to resume cattle exports to the United States, which were suspended on July 9, as reported by MBN. “The live cattle export industry has suffered losses of between US$25 million and US$30 million per month due to the closure of the US border,” López said.