A travel-associated human case of screwworm infection has been detected in Maryland. The patient had recently returned from a trip to El Salvador, a country affected by a screwworm outbreak. The Centers for Disease Control and Prevention (CDC) worked in conjunction with the Maryland Department of Health to investigate the case.
The CDC confirmed the diagnosis on August 4 after experts reviewed larvae images. According to Andrew Nixon, a spokesperson for the Department of Health and Human Services, the risk to public health in the United States from this introduction is very low.
New World screwworm, also known as myiasis, is a parasitic infestation of fly larvae that feeds on live flesh. A person can contract myiasis when females drop their eggs on or near a person’s wound, nose, or ears. It can also be transferred through ticks and mosquitoes after the fly attaches its eggs to the insects.
In the case of an infection, a lump will develop in the person’s tissues as the larvae grow and eat flesh. If left untreated, it can be fatal. Myiasis is not common in the U.S., with most cases occurring in people who have traveled to tropical areas where the infestation is more prevalent.
Livestock such as cattle, sheep, and goats are highly vulnerable to myiasis, making it a significant economic pest. The U.S. Department of Agriculture has announced plans to build a sterile fly facility in Texas to combat the pest, which could cost the state’s economy $1.8 billion in livestock deaths, labor costs, and medication expenses if an outbreak were to occur.
