Leishmaniasis in the United States

The virological and epidemiological landscapes are changing rapidly, and both health professionals and informed business travelers will have to make decisions under rapidly evolving circumstances. Long considered a tropical disease confined to South America, MENA, and South Asia, Leishmaniasis has managed to expand its range over the last few years. The last few months have seen a spate of media reports suggesting that the disease is now not only present but endemic to parts of the United States. While this is not cause for alarm in the immediate term, accurate information about the issues enables effective decision-making.

What is Leishmaniasis?

Leishmaniasis is a wide-ranging condition encompassing many possible symptom sets, all stemming from an infection of the parasitic protozoan Leishmania. Considered a Neglected Tropical Disease (NTD) by the US Center for Disease Control, leishmaniasis is a vector-borne illness generally transmitted by the bite of the sand fly (Phlebotomus papatasi). 

Initial detection and diagnosis of leishmaniasis can be difficult as the condition presents with a variety of symptom sets depending on the type of leishmaniasis in question.

The most common form of the disease, cutaneous leishmaniasis, may appear as a silent infection in some patients. For those who do display symptoms, those indicators may appear as bumps or lumps on the skin, ulcers that may or may not be covered with a scab or crust, and swollen glands, particularly near the sores. 

Visceral leishmaniasis is another manifestation of the disease, which presents a contrasting symptom set to cutaneous leishmaniasis. Visceral leishmaniasis may appear as a silent infection, but the most common symptoms include fever, weight loss, enlargement/swelling of the spleen and liver, and abnormal blood tests, including low red blood cell count (anemia), low white blood cell count (leukopenia), and low platelet count (thrombocytopenia). Visceral leishmaniasis may be known colloquially as kala azar or “black fever” in parts of South Asia. 

Mucocutaneous leishmaniasis is predominantly found in Bolivia, Peru, Brazil, and Ethiopia. As the name suggests, it results in skin and mucosal ulcers that damage or destroy the nose and mouth. 

Just as the symptoms vary, so do treatment paths of leishmaniasis depending on the variation of the disease in question. Liposomal Amphotericin B and Miltefosin have been shown to be effective in treating visceral leishmaniasis, while oral fluconazole or itraconazole may be effective in treating cutaneous leishmaniasis. A central issue in the battle against leishmaniasis globally is the disease’s resistance to many modes of treatment and the ways in which that resistance varies regionally. Research is ongoing.

Leishmaniasis in the United States

Until recently the CDC considered leishmaniasis infections to be an unusual occurrence in the US, generally brought home by travelers from a region in which the illness is prevalent. Researchers have long had concerns that this might change. However, citing a combination of circumstances, including “Climate change, the identification of competent vectors and reservoirs, a highly mobile populace, significant population groups with proven exposure history, HIV, and widespread use of immunosuppressive medications and organ transplant” as possible modes by which leishmaniasis could take root in the United States.

 A CDC team has recently identified a variety of leishmaniasis that is both endemic to the US and also genetically distinct from foreign varieties. Texas and the Southwest are the primary areas of concern at present, but cases have been identified across the Gulf Coast as well, including throughout the state of Florida. Due to a warming climate, leishmaniasis may be here to stay, and the CDC is working with state and local health agencies to inform healthcare providers that this once-exotic disease is now a concern. 

Leishmaniasis and Business Travel

Currently, there are no reasons to change domestic travel plans due to concerns about leishmaniasis in the United States, although some level of precaution may be in order. Globally, when traveling in regions where leishmaniasis is present, the Cleveland Clinic offers the following guidelines for avoiding infection or contact with the disease:

• Cover exposed skin with clothing, including long pants, long-sleeved shirts and socks.
• Wear EPA-registered insect repellent. The most effective repellents usually contain DEET.
• Kill sand flies indoors by spraying living and sleeping areas with insecticide.
• Sleep in a room with the windows closed or with screens in the windows.
• Sleep under mosquito bed netting. Use pre-treated with insect repellent for added protection.
• Sand flies are much smaller than mosquitoes. Netting and screens should have very small holes to keep flies out.

As always, informed caution is the best possible response, as is ensuring that business travel is accompanied by expert medical advice and around-the-clock support in order to ensure safety and health while traveling.