Human Case Of New World Screwworm Reported In U.S.
A recent case of New World screwworm myiasis in a human has been confirmed in the U.S. by officials from the Department of Health and Human Services and the Centers for Disease Control and Prevention. The individual affected was a resident of Maryland who had recently returned from El Salvador. Fortunately, the person has fully recovered, and subsequent surveillance efforts have not detected any screwworm flies in the surrounding areas, indicating a low risk of an outbreak.
New World screwworms, scientifically known as Cochliomyia hominivorax, are a type of blow fly found in tropical and sub-tropical regions of South America and the Caribbean. These flies lay their eggs on living mammals, such as in open wounds or mucous membranes, where the larvae then feed on living flesh. This unique behavior gives them their distinctive name as the larvae appear to “screw” themselves into the host’s tissue while feeding.
In humans, a New World screwworm infestation can be quite painful and lead to severe damage if left untreated. Physical removal and destruction of the larvae by a healthcare provider are the recommended treatment as no approved drugs are currently available for humans or animals. Untreated infestations can result in deadly consequences due to the risk of bacterial infections.
Historically, New World screwworms were present in the southern U.S. before eradication efforts successfully eliminated indigenous populations in the 1960s. However, outbreaks have occurred in other areas, resulting in significant economic costs. Since 2023, NWS populations have been advancing north through Central America and Mexico.
While the recent case in the U.S. appears to be isolated, it serves as a reminder of the interconnected nature of our global community. Vigilant surveillance systems and proactive research efforts are essential to safeguard public health in a changing world. By staying ahead of potential threats like New World screwworms, we can better protect the well-being of our communities.
