The recent confirmation of the first human case of screwworm in the US has raised concerns about this parasitic threat. Once eradicated in the 1960s, the screwworm has now resurged in Central America and Mexico, prompting questions about how it arrived in the US and what risks it poses. Below, we explore what the screwworm is, how it spreads, and what measures are being taken to prevent a larger outbreak.
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What exactly is the screwworm?
The screwworm is a parasitic fly whose larvae burrow into living flesh, causing severe tissue damage. It primarily affects livestock but can also infect humans. The parasite was eradicated in the US decades ago but has recently reappeared in Central America and Mexico, raising concerns about its potential spread northward.
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How did the screwworm reach the US?
The screwworm has been spreading northward through Central America and Mexico since 2023. The recent human case in Maryland indicates that the parasite is now reaching US borders, likely through infected livestock or accidental transport. Authorities are closely monitoring the situation to prevent further spread.
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Could the screwworm affect people and animals in the US?
While the risk to the general public remains low, the screwworm poses a significant threat to livestock and potentially to humans if they come into contact with infected wounds. The recent case in Maryland highlights the importance of vigilance and rapid response to contain the parasite.
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What is being done to stop the screwworm from spreading?
US authorities are taking proactive measures, including building a sterile fly production facility in Texas. This facility will produce sterile screwworms to release into affected areas, disrupting the parasite's breeding cycle and preventing further outbreaks.
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Is there a risk of a large outbreak in the US?
There is concern about the potential for a larger outbreak, especially given the recent case and the parasite's spread in neighboring countries. However, with the new control measures and monitoring efforts, officials aim to contain the threat before it becomes widespread.
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How serious is the economic impact of screwworm outbreaks?
The economic stakes are high, with estimates of up to $1.8 billion in damages to the cattle industry in Texas alone. The parasite damages livestock, leading to costly treatments and loss of productivity, which underscores the importance of swift containment efforts.