Mexico Launches Screwworm Suppression Pilot in Yucatan

The Ministry of Agriculture and Rural Development (SADER) has launched the Pilot Plan for the Suppression of the New World screwworm (NWS) in Yucatan. Under the program, coordinated actions will be implemented over a 10-week period to significantly reduce the pest population and advance its control.

Joaquín Díaz, Governor, Yucatan, said that more than 1,300 cases have been treated in the state without the death of any animals and that, thanks to coordinated work with federal authorities, 86 active cases are currently being reported. According to official data, Yucatán has 18,521 livestock production units.

Javier Calderón, Director-in-Chief, National Service for Agrifood Health, Safety and Quality (SENASICA), stated that the Pilot Plan demonstrates that inter-institutional coordination is the most effective way to turn a sanitary challenge into an opportunity to strengthen the livestock sector.

He stressed that social participation is essential for the success of the strategy, as animal care, wound treatment, reporting and field surveillance constitute the first line of defense. He added that the lessons learned in Yucatán will serve as a guide to scale the strategy to other regions of the country, positioning Yucatán as a pioneer of an animal health model with the potential to become a reference in the southern-southeastern region.

Gabriel Ayala, Director General of Animal Health, Senasica, highlighted that, thanks to commitment and coordination with state authorities and the productive sector, the spread of the pest has been contained for more than 13 months. He specified that the objective is to reduce fly density over a 10-week period to prepare the ground for the future release of sterile flies produced in Mexico.

Edgardo Medina, Yucatan’s Ministry of Rural Development, said efforts have been coordinated with SADER to raise awareness of the issue among producers. He noted that 42 technicians are currently providing field support to production units, 16 of whom belong to Senasica.

To increase effectiveness, the Pilot Plan includes a series of actions. First, field brigades will be formed to operate in three polygons with a high incidence of screwworm, covering more than 1,500km2. Likewise, outreach and promotional efforts will be intensified across the state, particularly in livestock regions, to encourage producers to participate in the plan.

Communication in the field will also be strengthened through loudspeaker announcements in Indigenous languages and the distribution of printed materials at key meeting points for the sector, such as veterinary pharmacies, livestock unions and slaughterhouses, among others. In addition, inspections by specialized Senasica personnel will continue, along with movement controls through the operation of seven Internal Verification and Inspection Points (PVI), nine Verification and Inspection Sites (SI), seven Itinerant Routes (ITI), and five new control points currently undergoing authorization.

What Is the Current Screwworm Situation in Yucatan?

According to the state’s Ministry of Rural Development, from March 5, 2025, to date, Yucatan has recorded a cumulative total of 1,307 cases. Authorities also reported 54 new cases, with Merida and Tizimin registering the highest number of new cases, with 15 and 16, respectively.

However, Esteban López, President, Regional Livestock Union of Eastern Yucatan (Ugroy), noted that the pest has not generated a significant economic impact for producers beyond the cost of medications for treatment. “The expenses associated with screwworm are related to purchasing medicines to treat the wounds. We have not had losses due to the worm,” the union leader said.

He explained that if the worms are detected within the first few days, the healing process takes two to three days and requires little medication. However, if detection occurs five or six days later, when the myiasis is more advanced, the animal’s recovery can take up to a month, significantly increasing medication costs.

“There have been no major impacts on livestock sales. The issue is limited to treatment, and once the animal recovers, it returns to its normal activity. If it is for fattening, it continues until it reaches the marketing stage, and if it is breeding stock, it resumes its reproductive cycle,” López said.