The U.S. Department of Health and Human Services (HHS) reported the first human case of travel-associated New World screwworm, a flesh-eating parasite, in the United States. The case, confirmed by the Centers for Disease Control and Prevention (CDC) on August 4, involved a patient who had recently traveled from El Salvador.
However, an earlier report from Reuters, citing beef industry sources, had stated that the individual had traveled from Guatemala. HHS spokesman Andrew G. Nixon did not clarify the discrepancy but emphasized that the “risk to public health in the United States from this introduction is very low.”
The differing accounts from the U.S. government and industry sources are likely to heighten anxiety among cattle ranchers and beef producers, who are already on high alert as screwworm has been moving northward from Central America. The U.S. Department of Agriculture (USDA) estimates that a screwworm outbreak in Texas, the largest U.S. cattle-producing state, could lead to an estimated $1.8 billion in losses due to livestock deaths, labor costs, and medication expenses.
Screwworms are parasitic flies that lay eggs in the wounds of warm-blooded animals, and their larvae burrow into living flesh, which can be fatal if left untreated. While human cases are rare, a livestock economist at Texas A&M University was asked to prepare a report for USDA Secretary Brooke Rollins on the potential impacts of a border closure to Mexican cattle.
