The US Department of Health and Human Services (HHS) has reported the first human case of New World screwworm in the United States since 1966, according to a statement on Sunday. The case, confirmed by the Centers for Disease Control and Prevention (CDC) on 4 August, involved a patient who had returned from travel to El Salvador, an HHS spokesperson told Reuters.
However, beef industry sources have provided conflicting information, stating that the individual had travelled from Guatemala. The HHS spokesperson did not address this discrepancy. The risk to public health in the US is considered very low, according to HHS.
The confirmation comes as the screwworm, a parasitic fly that lays eggs in wounds of warm-blooded animals, has been moving northward from Central America and southern Mexico. The US Department of Agriculture (USDA) has estimated that an outbreak could cost Texas, the largest cattle-producing state, approximately $1.8 billion in livestock deaths, labour costs, and medication.
State veterinarians, including Beth Thompson of South Dakota, expressed frustration with the CDC's lack of transparency regarding the case. Thompson said she was notified of the human case within the last week by a person with direct knowledge, but the CDC deferred questions to Maryland during a call with state animal health officials.
Screwworm infestations, while rare in humans, can be fatal if left untreated. Treatment involves removing hundreds of larvae and disinfecting wounds. The patient in this case has been treated, and prevention measures have been implemented in Maryland, according to industry emails.
