Anna Hartz
US screwworm cases rise to 15 with new livestock infections in Texas
Keeping livestock healthy is a major concern for ranchers and animal health officials. Diseases and parasites can spread quickly if they are not caught early. That is why authorities continue to closely monitor the return of the New World screwworm in the United States.
Twelve cases are still active
The threat from the New World screwworm remains nearly three weeks after the first case of the parasitic fly was reported in the country, reports USAToday.
Over the weekend, the U.S. Department of Agriculture announced three additional cases involving livestock. Two new cases were found in cattle in Edwards County. Another case was confirmed in a sheep in Crockett County.
As of 9 a.m. on June 22, there have been 15 confirmed cases in the United States. Twelve of those cases are still active, while three are now inactive.
The USDA considers a case inactive when an animal has fully recovered. Cases can also become inactive if officials have taken steps to prevent the parasite from spreading after an untreated animal dies.
Texas remains the only state reporting new cases since the New World screwworm returned to the United States decades after it was eliminated.
According to the USDA, the New World screwworm affects livestock, pets and wildlife. In rare cases, it can also affect people and birds. The larvae feed on the living tissue of warm-blooded animals.
Not contagious to people
Officials say the current risk to people and animals in the United States remains very low. The parasite is not contagious.
Infestations begin when a female fly lays eggs in a wound or body opening. The eggs hatch into larvae that feed on living tissue for about seven days. The larvae then fall to the ground and develop in the soil. Adult flies emerge between seven and 54 days later.
Texas has recorded 14 cases so far. They have involved cattle, goats and sheep in several counties, including Edwards, Zavala, La Salle, Gillespie, Sutton, Tom Green and Crockett.
A separate case involved a dog from Lea County, New Mexico. The infection was first reported by a veterinarian in Texas on June 7. The USDA now lists that case as inactive.
The Texas Animal Health Commission has expanded quarantine zones across parts of West, South and Central Texas. The restrictions are intended to limit animal movement and prevent further spread. Officials say the quarantine orders will remain in place until they are lifted by the commission.
