A confirmed case of New World screwworm in the U.S. raises alarms over biosecurity and public health, echoing concerns from decades past.
Story Highlights
- First U.S. human case of travel-associated New World screwworm confirmed in Maryland.
- Increased travel from outbreak-affected countries raises biosecurity concerns.
- The livestock industry faces potential economic risks.
- Federal and state agencies intensify border and surveillance measures.
First U.S. Human Case of Screwworm in Decades
On August 24, 2025, the U.S. Department of Health and Human Services (HHS) reported the first confirmed human case of travel-associated New World screwworm (NWS) in Maryland. The individual had recently returned from El Salvador, a country experiencing an outbreak. This confirmation by the Centers for Disease Control and Prevention (CDC) on August 4, 2025, has heightened concerns about the pest’s potential spread from Central America.
The New World screwworm, a parasitic fly whose larvae feed on living tissue, was eradicated from the U.S. in the 1960s through coordinated federal programs. However, it remains endemic in parts of South America and the Caribbean. This recent case underscores the risk posed by increased international travel, which can inadvertently introduce such pests into the U.S.
Impact on Public Health and Agriculture
The USDA has quickly responded by announcing expanded plans to prevent the establishment of NWS in the U.S. This includes intensified border controls and surveillance measures. The livestock industry, particularly cattle ranchers and beef producers, is on high alert due to the pest’s potential to cause severe economic losses and animal suffering. So far, no animal cases have been reported in the U.S. this year, but the vigilance remains critical.
Federal agencies emphasize that the risk to general public health is very low, yet the importance of maintaining biosecurity cannot be overstated. The USDA, CDC, and state health departments are working collaboratively to ensure that the pest does not establish itself in American soil.
Broader Implications and Future Measures
In the short term, heightened surveillance and increased scrutiny of travelers from affected regions are expected. Long-term strategies may involve stricter border controls and potentially expanded eradication programs. The situation places pressure on federal and state agencies to act decisively and transparently, ensuring public confidence in the measures being taken.
With the livestock industry at risk, economic implications could include potential trade disruptions if the pest were to affect livestock health. Public health agencies must allocate resources efficiently to prevent further cases and protect American agriculture.
While the current case is isolated, it serves as a reminder of the interconnectedness of global health and the need for vigilance against biosecurity threats. The coordinated efforts of various agencies aim to prevent any further incursions and protect both public health and the agricultural economy.
