Risk to Hawaiʻi remains very low following recent detections of New World screwworm in animals on the U.S. mainland, according to the Hawaiʻi Department of Agriculture and Biosecurity and the Hawaiʻi Department of Health, which are enacting proactive, protective measures.
As of July 3, federal agencies reported 16 domestically acquired animal cases and no domestically acquired human cases nationally. To date, there have been no detections of New World screwworm in Hawaiʻi in animals or people.
“Hawaiʻi’s strong import rules, inspections, surveillance, and rapid-response systems are built for exactly these situations,” said Sharon Hurd, Department of Agriculture and Biosecurity chairperson. “We are fully engaged in preventing New World screwworm from entering the state.”
New World screwworm (Cochliomyia hominivorax) is a serious pest that affects livestock, pets, wildlife, and, less commonly, people and birds.
The New World screwworm, a parasitic fly, lays eggs in wounds or body openings, causing an infestation of larvae (maggots) in tissue through a process called myiasis. Unlike common maggots that feed on dead tissue, New World screwworm maggots feed on living tissue, leading to injury and health complications. The presence of New World screwworm does not impact food safety.
Insect identification by an entomologist is required to determine whether it is New World screwworm. Infestations are treatable in people by physically removing all larvae and managing the wound; in animals, they are treated with larval removal and systemic antiparasitic agents.
New World screwworm affects animals and people, but the risk to Hawaiʻi is currently very low. The first detection in the U.S. was found in a Texas calf on June 3 and has since been detected in other cattle, goats, sheep, and one dog. There was also a detection in one dog in New Mexico.
The Department of Agriculture and Biosecurity has updated its animal import requirements to include inspection and certification that animals are free of New World screwworm. The Department of Agriculture and Biosecurity recommends the following for animal owners:
- Keep all wounds on people and animals clean and covered until healed.
- Inspect livestock and pets regularly for cuts, sores, or unusual irritation.
- Seek veterinary care promptly for any non-healing animal wounds.
- Follow all import and quarantine requirements for animals traveling to Hawaiʻi.
People traveling to areas where New World screwworm flies have been reported can take the following additional actions to protect themselves:
- Sleep indoors with closed windows or screened open windows. If sleeping outside, sleep under a bed net or inside a screened tent.
- Protect your skin from insects.
- Use an EPA-registered insect repellent.
- Treat clothing and gear with products containing 0.5% permethrin.
- Wear loose-fitting, long-sleeved shirts and pants, hats, and socks.
Symptoms of myiasis include a lump in tissue beneath the skin. If you experience symptoms, contact your healthcare provider. Call the Disease Outbreak Control Division Disease Reporting Line at 808-586-4586.
Current New World screwworm case updates and information are available from the U.S. Animal and Plant Health Inspection Service website.
Although the risk of infestation in Hawaiʻi is considered low, pet and livestock owners are encouraged to contact their private veterinarian if they have any health concerns or observe unusual wounds or signs of possible infestation.
