Authorities have detected the New World screwworm in Texas for the first time since 1966 [1].
The return of this parasitic fly threatens the health of livestock and wildlife, posing a significant risk to the U.S. cattle industry, which is valued at $113 billion [2, 6].
Officials said a second case of the parasite was confirmed in a one-month-old calf [2]. This second instance occurred in Zavala County, located between five and 5.6 miles from the site of the first detection [2, 3].
The New World screwworm is a parasitic fly that causes severe tissue damage in its hosts. Because the larvae feed on living tissue, the parasite can cause extensive flesh-eating wounds in animals. This biological threat has led to an expanded statewide disaster declaration to coordinate containment and eradication efforts.
Federal and state agencies are working to prevent the parasite from spreading further into the livestock population. The rapid response is intended to mitigate the potential for a larger outbreak that could disrupt agricultural trade and animal welfare across the region.
Canada has already implemented bans on cattle from Texas as the outbreak spreads [3]. The USDA is monitoring the situation in Zavala County to determine the extent of the infestation and the effectiveness of current quarantine measures.
“First detection of New World screwworm in Texas since 1966”
The reappearance of the New World screwworm after six decades represents a significant biosecurity breach. Because the parasite targets living tissue rather than necrotic flesh, it can quickly incapacitate livestock, leading to massive economic losses and trade restrictions. The immediate expansion of a disaster declaration suggests that officials view the proximity of the two cases—separated by only a few miles—as evidence of an active local population rather than an isolated incident.
