Introduction to Gusano Barrenador and Its Impact
The Secretaría de Fomento Agroalimentario y Desarrollo Rural (Sefader) of the state of Oaxaca confirmed this week the first case of parasitic infestation, or miasis, caused by the gusano barrenador (screw worm) in a domestic animal. The case involved a dog from the community of San Juan Yaeé, located in the Sierra de Juárez region.
The Affected Dog and Its Treatment
The dog was diagnosed with the presence of larvae from Cochliomyia hominivorax, the scientific name for the screw worm affecting livestock. After receiving timely veterinary care, the canine is now out of danger and under active surveillance by health authorities.
Alert for Pet Owners
This case serves as a warning to pet owners, as although this pest primarily affects livestock, it can also impact domestic animals exposed to open wounds. Sefader urges the public to report any suspicions to the Committee Estatal de Fomento y Protección Pecuaria de Oaxaca (CEFPPO) or Senasica.
Gusano Barrenador: History and Recent Resurgence
The screw worm has been the target of eradication campaigns in Mexico since 1991. However, its recent reappearance in southern Mexico has led to the reinforcement of control operations, including the use of trained dogs to detect active wounds.
Human Cases of Screw Worm in Mexico
According to the latest data from the Sistema Nacional de Vigilancia Epidemiológica (SINAVE) as of June 13, 2025, there have been 17 confirmed human cases of miasis caused by Cochliomyia hominivorax in Mexico.
- Chiapas: Mapastepec, Tapachula, Escuintla, Villa Comaltitlán, Huixtla, Pijijiapan, Tonalá, Ocosingo, Chilón, Mazatán
- Campeche: Candelaria, Carmen
- Oaxaca: Oaxaca de Juárez (residence of the detected case in Yajalón)
Most patients have underlying risk factors such as chronic diseases (diabetes, cancers, immunodeficiencies), and the lesions are primarily located on the head, limbs, oral cavity, and genitals. Some cases have required hospitalization.
Early detection and active surveillance in rural areas are crucial to prevent the spread of this parasitic infestation.
Key Questions and Answers
- What is the gusano barrenador? The gusano barrenador, or screw worm, is a parasite that affects livestock and occasionally domestic animals. It is caused by the fly Cochliomyia hominivorax.
- Why is this case significant? This is the first reported case of miasis caused by gusano barrenador in a domestic animal in Oaxaca, raising awareness among pet owners.
- What are the risk factors for human infection? People with chronic diseases, such as diabetes or immunodeficiencies, are more susceptible to infection. Lesions often occur on the head, limbs, oral cavity, and genitals.
- How is the infestation controlled? Control measures include eradication campaigns, surveillance operations with trained dogs to detect active wounds, and public reporting of suspicions.
