The first human case of a flesh-eating parasite infestation has been confirmed in the US, authorities say, BBC reported.

New World screwworm (NWS) myiasis was found in a patient who returned to the US from El Salvador, the Department of Health and Human Services said on Monday. The case was confirmed on 4 August.

NWS myiasis is a parasitic infestation of fly larvae, or maggots, caused by parasitic flies, according to BBC.

The pest primarily affects livestock, and authorities have said the risk to US public health was currently "very low".