A tropical parasite, passed through the bite of a sand fly, is causing skin infections in the US

Sand flies, tiny insects known for their disease-transmitting bites, have emerged as a new health concern in the U.S., particularly in warm, rural areas like Texas and Oklahoma. These flies, smaller than mosquitos and active at night, transmit a parasite causing leishmaniasis, an infectious disease previously associated with tropical regions. Recent findings by the CDC indicate cases of skin infections from Leishmania mexicana in individuals with no travel history, suggesting local transmission.

The disease manifests as skin sores that erupt into painless ulcers, potentially disfiguring if left untreated. While the more severe visceral leishmaniasis isn't currently transmitted within the U.S., there's concern about sand flies expanding their range due to climate change. This shift could increase local transmission risks, especially as some sand fly species have been identified as far north as Delaware and New Jersey.

Preventive measures against sand fly bites include using DEET-containing repellents and treating gear with permethrin, particularly during outdoor activities in affected areas. Increased awareness and prompt treatment of leishmaniasis are crucial, as most U.S. doctors are unfamiliar with the disease. Treatment involves antiparasitic medications, emphasizing the need for broader knowledge and precautionary actions amidst the flies' expanding habitats.