US Sees First Screwworm Case in 60 Years: Economic and Health Concerns Rise

The Return of Screwworm

The New World screwworm, a flesh-eating parasite that infects cattle and other warm-blooded animals, has been detected in a calf in Texas, marking the first case in the US in 60 years. The parasite, which was previously eradicated in the US in 1966, is believed to have traveled from Central America to Mexico before reaching Texas.

Understanding Screwworm and Its Risks

Screwworm is a parasitic fly that lays its eggs in the wounds of warm-blooded animals. The larvae then hatch and eat the living tissue of the infected animals, causing painful and progressive wounds. Humans can also be infected, although it is rare. The parasite can be devastating to cattle and wildlife, and can even be fatal if left untreated.

Economic Impact and Beef Prices

The outbreak could have significant economic implications for the US livestock industry, with estimated losses of $1.8 billion in Texas alone. The US has already halted cattle imports from Mexico, which has contributed to rising beef prices. A further outbreak could lead to shortages in the cattle supply, putting other livestock and household pets at risk, and driving up beef prices even higher.

Response and Treatment

The US Department of Agriculture (USDA) has established a quarantine zone around the affected farm and is working to treat the infected calf and eliminate the larvae. The primary measure is vigilance, identification, and isolation of cases, treatment, and elimination of larvae, and controlling movement of animals. A program of sterile male release is also considered a long-term method of controlling the fly.

Future Outlook and Concerns

The reappearance of screwworm in the US raises concerns about the potential for further outbreaks and the impact on the livestock industry. Experts point to a combination of factors, including disruptions to sterile-fly programs during the COVID-19 pandemic, increased movement of livestock and people, and favorable weather conditions, as contributing to the parasite's resurgence. The US will need to take proactive measures to prevent further outbreaks and mitigate the economic impact on the livestock industry.