What KDHE alert told health departments and providers
New World screwworm was eradicated from the United States using the sterile insect technique, where radiation is used to sterilize male flies that are released into the wild where they mate with females and produce unfertilized eggs. The U.S. has since worked to maintain a biological barrier in Central America that contains the pest to South America. That barrier has broken down in recent years.
“There is an ongoing outbreak of New World screwworm in Central America and Mexico,” the KDHE alert said. “New World screwworm is the fly Cochliomya hominvorax, which lays its eggs on wounds of animals and people. The larvae that hatch only feed on living tissue and cause severe tissue destruction and, ultimately, death if untreated.”
A travel-associated human case was reported in Maryland in a patient who was returning from El Salvador. Health officials have said there is no ongoing risk to the public from that case.
“Although this is primarily a disease of animals, people can also be infested,” the KDHE alert said. “People who travel to endemic and outbreak areas, spend time with livestock animals in these areas, sleep outdoors, and who have open wounds, such as from scratches, cuts, insect bites, or recent surgeries are at a greater risk of infection.”
The alert told health care providers to contact the KDHE epidemiology hotline if a human case of New World screwworm is suspected or diagnosed. The state asked local health departments to provide education to local providers, including on prompt reporting.
Suspected animal cases should be reported to the Kansas Department of Agriculture.
“Symptoms of NWS myiasis in humans include seeing larvae (maggots) in and around open wounds; unexplained wounds that do not heal or become worse over time; painful wounds or sores; bleeding from sores; feeling the movement of larvae in and around the wound, in the nose, mouth, or eyes; and a foul-smelling odor coming from the site of infection,” KDHE said. “These infestations are typically very painful; however, depending on location, larvae may not be readily visible. Secondary bacterial infections and systemic illness can also occur.
“Treatment of NWS in humans requires the complete, physical removal of all larvae. Depending on the location of the larvae, this may require surgical removal.”
The alert also requested education of providers on propoer disposal of larvae.
“Never dispose of larvae in the trash,” KDHE said. “Improper disposal of larvae can lead to the establishment of a local fly population when those larvae pupate and turn into adults. This would pose a serious risk to domestic and wild animals and would require a large-scale, coordinated response by local, state, and national partners to conduct human, animal, and environmental surveillance to eradicate the flies.”
As reported in the Topeka Capital Journal
