New World Screwworm Fly Resurgence Threatens Health of Cattle and Humans
The New World Screwworm fly has resurfaced in Mexico, prompting the USDA to halt imports of live cattle, horses, and bison. This pest could threaten both livestock and human health if not controlled. Past outbreaks have shown significant economic impact, making containment efforts critical.
The New World Screwworm (NWS) fly, previously assumed eradicated from the U.S. since 1966, has resurfaced as a potential health threat due to a recent outbreak in Mexico. This alarming news has led to immediate measures, including a stoppage of imports of live cattle, horses, and bison at the southern border of the United States. The action was announced by U.S. Department of Agriculture (USDA) Secretary Brooke Rollins through an official post on X, stating, “Due to the threat of New World Screwworm I am announcing the suspension of live cattle, horse, & bison imports through U.S. southern border ports of entry effective immediately.”
Secretary Rollins further conveyed the severity of the situation, recalling the historical impact of a similar invasion. She noted, “The last time this devastating pest invaded America, it took 30 years for our cattle industry to recover. This cannot happen again.” This introduction of restrictions reflects a cautious response to an emerging issue that could have widespread consequences.
An NWS fly is particularly notorious for its life cycle, which begins when a female lays her eggs in the open wounds of warm-blooded animals, like cattle and horses. When these eggs hatch, they turn into larvae, or maggots, which then burrow into the flesh, causing severe damage. The USDA’s Animal and Plant Health Inspection Service (APHIS) describes the maggots’ movement akin to a screw being driven into wood, hence the name “screwworm.”
As the APHIS website describes, “Maggots cause extensive damage by tearing at the hosts’ tissue with sharp mouth hooks” leading to enlarged wounds that can attract even more flies. The Centers for Disease Control and Prevention (CDC) has also highlighted that, although rare, these infestations could affect humans, especially if they have open wounds.
“People who travel to these areas, spend time among livestock animals, sleep outdoors and have an open wound are at greater risk of becoming infested with NWS,” the CDC advises. Vulnerable populations, including the immunocompromised, seniors, and young children, are particularly at risk, as well as individuals who have had recent surgery. As stated by the CDC, “wounds as small as a tick bite may attract a female to feed.”
The USDA has cautioned that if another outbreak were to occur in the United States, the potential ramifications could be devastating, leading to complications for pets, livestock, wildlife, and even humans suffering from screwworm myiasis. Past estimates reveal that in the 1950s and 1960s, livestock producers in the southwestern region of the U.S. lost approximately $50 million to $100 million each year due to the presence of NWS.
The USDA indicates the losses were more significant in the Southwest region, likely due to greater livestock populations and suitable overwintering conditions for the flies. While the greatest success was achieved in eradicating NWS in 1966, the flies made a brief reappearance in the Florida Keys in 2016, primarily affecting the local endangered deer population, but that outbreak was eradicated by March 2017.
These recent developments highlight significant cause for concern as the New World Screwworm re-emerges from near oblivion, underscoring the need for vigilance and swift action. There are serious risks associated with an outbreak, which could hurt both agricultural interests and human health.
In summary, the re-emergence of the New World Screwworm fly poses a serious threat to livestock and potentially to humans. With immediate import restrictions in place as a proactive measure, the USDA emphasizes the need to prevent a repeat of past outbreaks that caused extensive economic losses. Stakeholders must remain alert as varied populations, especially those at higher risk, could face serious health repercussions if an outbreak occurs in the U.S.
Original Source: www.foxnews.com
