Parasitic Skin Disease Spread by Sand Flies May be More Common in Texas, CDC Analysis Suggests
A new analysis from the Centers for Disease Control and Prevention (CDC) indicates that a parasitic skin disease, typically spread through the bite of sand flies, may be more widespread in Texas than previously believed. Leishmaniasis, caused by Leishmania protozoa, is an infection that can lead to long-lasting skin lesions appearing weeks or months after exposure. While most cases in the U.S. have been found in individuals who have traveled abroad to certain tropical regions, new data presented at the annual American Society of Tropical Medicine and Hygiene conference reveals a potential increase of this disease in Texas and other southern states.
Researchers examined 1,222 cases of leishmaniasis between 2005 and 2019. Although only 86 tissue samples were from individuals with no international travel history, scientists detected a genetically unique strain of the Leishmania parasite, suggesting a local spread. “We cannot say that it is exclusive to Texas, but from the samples that were submitted to CDC, the majority were from Texas,” said CDC senior advisor Vitaliano Cama.
Texas is the only state that requires health professionals to report leishmaniasis cases. However, there is no data available from other states to suggest a nationwide issue. Mary Kamb, an epidemiologist involved in the study, stated, “This genetic information adds credence to this idea that leishmaniasis is occurring here in the United States, it’s endemic here in the United States, at least in Texas and maybe southern border states.”
Although public health officials believe the risk of leishmaniasis is low and it does not pose a serious threat, Kamb suggested the implementation of a national reporting tool to help healthcare providers identify and treat cases more effectively.
Currently, there is no vaccine or specific drug to prevent leishmaniasis. It is typically diagnosed by doctors who perform biopsies of infected skin lesions. Initial symptoms appear as bumps and may develop into ulcers over time. While some sores can heal on their own, others may leave behind scars. The CDC also warns of a more severe form of leishmaniasis caused by another parasite in the same genus, which can damage internal organs, although cases of this type are rare.
Given that sand flies are commonly found in forested areas, health experts advise individuals to minimize their risk of infection by covering their skin and applying insect repellents and insecticides when outdoors.