Yucatán Screwworm Cases Now at 548

Yucatán, Mexico — The state of Yucatán has reported 67 new cases of screwworm infestation, bringing the total number of registered cases since the beginning of the sanitary contingency to 548. Among these are three human cases, all of whom have received medical treatment.

The Secretariat of Rural Development (Sader) reported that the affected animals, detected across 29 municipalities, presented lesions in the navel, cervical region, vulva, and ears. These wounds were primarily caused by fights among the animals themselves, barbed wire fences, or bites from hematophagous bats.

The municipalities with the highest number of cases are Mérida, with seven, and Tizimín, with six. Oxkutzcab, Baca, and Tunkás each reported five cases. Halachó and Temozón registered four cases each; Cacalchén, Izamal, and San Felipe reported three each; and Motul, Maxcanú, and Cenotillo reported two cases each.

The towns of Ixil, Conkal, Tekit, Yaxkukul, Chacsinkín, Mocochá, Kantunil, Kinchil, Valladolid, Sucilá, Tekax, Teabo, Panabá, Espita, Dzitás, and Chichimilá each reported one case.

The affected species include cattle, swine, canines, and equines, with ages ranging from two days old to twelve years. The evolution was favorable in the majority of the animal patients, who were discharged after receiving treatment.

Sader has issued a call to livestock producers to remain vigilant of their animals to prevent screwworm infestation. The agency has made the telephone number 800 751 21 00 available for producers to receive assistance.

What is Screwworm and How Does It Affect Livestock?

Screwworm originates from the larvae of the fly species Cochliomyia hominivorax, which feeds on the living tissue of mammals—in this case, cattle or livestock in general—when they have small wounds.

According to official information, there are two species of fly that cause this myiasis: the New World screwworm fly (Cochliomyia hominivorax) and the Old World screwworm fly (Chrysomya bezziana).

This insect deposits its eggs in the superficial wounds of animals. Within a period of 12 to 24 hours, the larvae emerge and begin to feed on the living tissue. This process can last between four and eight days, causing considerable damage to the affected animals. It is a pest that represents a serious threat to livestock health and, in some cases, can also affect humans.