The recent confirmation of the first human case of screwworm in the US has raised concerns about this aggressive parasite's resurgence. Once eradicated in the 1960s, the screwworm is now re-emerging in North America, primarily affecting livestock but also posing potential risks to humans. Understanding how it arrived in the US, what threats it poses, and what measures are being taken can help clarify this alarming development. Below, we explore common questions about this parasite and the ongoing response to its spread.
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What exactly is the screwworm?
The screwworm is a parasitic fly whose larvae burrow into the flesh of warm-blooded animals, including livestock and humans. It causes severe tissue damage and can lead to death if untreated. The species was eradicated from the US in the 1960s but remains a significant threat in Central America and Mexico.
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How did the screwworm reach the US?
The recent case in Maryland involved a patient who had traveled from El Salvador, where outbreaks have been increasing since 2023. The parasite has been spreading northward through Central America and Mexico, and climate factors, along with increased movement of animals and people, have contributed to its re-emergence in the US.
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Could the screwworm affect people in the US?
While the risk to the general public is considered low, the screwworm can infect humans, especially those in close contact with infected animals or in rural areas. The recent case highlights the importance of monitoring and controlling its spread to prevent potential health issues.
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What measures are being taken to stop the screwworm from spreading?
US authorities are constructing a sterile fly facility in Texas to produce and release sterile males, which will help reduce the wild population of screwworms. Additionally, strict quarantine and monitoring protocols are in place for livestock and travelers coming from affected regions.
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How common are screwworm outbreaks today?
Screwworm outbreaks are now rare in the US but remain common in parts of Central America and Mexico. The recent resurgence poses a threat to livestock industries and requires ongoing vigilance and control measures to prevent re-establishment in the US.
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What is the economic impact of screwworm outbreaks?
In regions like Mexico, outbreaks have caused billions in losses due to cattle deaths and decreased exports. The US is investing millions in prevention efforts to protect its livestock industry and avoid similar economic damage.