The danger of screwworm in animals and humans
The screwworm (Cochliomyia hominivorax) represents a serious threat to animal and human health, especially in tropical regions such as the Isthmus of Tehuantepec in Oaxaca, Mexico. According to veterinarian Juan Bautista Pérez, this parasite spreads through exposed wounds, where it deposits its larvae, which feed on living tissue, aggravating the injuries and generating severe complications.
Life cycle and mechanism of infection
The adult fly deposits up to 500 eggs in open wounds of animals or humans. In just 24 hours, these hatch, releasing larvae that immediately begin to consume living tissue. For seven days, the larvae remain in the wound, causing intense pain, a bad putrefactive odor, and systemic symptoms such as loss of appetite and depression. Subsequently, they fall to the ground to complete their metamorphosis into adult flies in approximately 10 days, restarting the cycle.
The name “screwworm” derives from its behavior: the larvae penetrate vertically into the meat, making early detection difficult. Unlike other myiasis, this species does not consume dead tissue, which accelerates damage and increases the risk of secondary infections.
Impact on pets, livestock and humans
Originally associated with livestock, the parasite now affects pets and humans. In animals, the infestation causes necrotic wounds and sepsis if untreated. In humans, symptoms are similar, with cases reported in rural areas where medical care is limited. Dr. Pérez emphasizes that any exposed wound in endemic areas should be protected with bandages and repellents.
Treatment and control measures
Treatment requires immediate veterinary or medical intervention. Specific larvicides are applied and manual extraction of the parasites is carried out. In addition, it is mandatory to report cases to authorities such as Senasica in Mexico, to implement containment strategies. Prevention includes:
- Monitor for wounds in pets during trips to risk areas.
- Use repellents and cover injuries with sterile gauze.
- Avoid areas with high fly density, especially in hot and humid climates.
This parasite not only compromises animal welfare, but also represents a public health problem, given its zoonotic potential. Collaboration between veterinarians, doctors and health authorities is key to its eradication.
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