Leishmaniasis in the United States: Emerging Issues in a Region of Low Endemicity

Abstract

Leishmaniasis, a chronic and persistent intracellular protozoal infection caused by many different species within the genus Leishmania, is an unfamiliar disease to most North American providers. Clinical presentations may include asymptomatic and symptomatic visceral leishmaniasis (so-called Kala-azar), as well as cutaneous or mucosal disease. Although cutaneous leishmaniasis (caused by Leishmania mexicana in the United States) is endemic in some southwest states, other causes for concern include reactivation of imported visceral leishmaniasis remotely in time from the initial infection, and the possible long-term complications of chronic inflammation from asymptomatic infection. 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 all create the potential for increased frequency of leishmaniasis in the U.S. Together, these factors could contribute to leishmaniasis emerging as a health threat in the U.S., including the possibility of sustained autochthonous spread of newly introduced visceral disease. We summarize recent data examining the epidemiology and major risk factors for acquisition of cutaneous and visceral leishmaniasis, with a special focus on implications for the United States, as well as discuss key emerging issues affecting the management of visceral leishmaniasis.

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“…Visceral leishmaniasis is a chronic infection, associated with the high mortality and morbidity (Brindha et al, 2021;Priyamvada et al, 2021;Mann et al, 2021;Sundar et al, 2018;Kumar et al, 2020aKumar et al, , 2020b. A potential concern is the recent identification that 19.5% of Iraq-deployed American soldiers have blood testing which suggests that they have asymptomatic visceral leishmaniasis, including 1% with parasitemia as measured by polymerase chain reaction, persisting up to a decade after return to the U.S (Curtin and Aronson, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017). It is a life-threatening infectious disease affecting many people around the globe and killing 50,000 individuals a year (Rijal et al, 2019;Mann et al, 2021;Singh et al, 2016aSingh et al, , 2016bPeters and Prasad, 1983;Boelaert et al, 2009;Bora, 1999;Tejaswi and Rajan, 2020;WHO, 2005).…”

“…Cutaneous leishmaniasis is globally increasing with significant female infections (2.35 million cases) (Curtin and Aronson, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017 Croft andOlliaro, 2011;Mann et al, 2021). Climatic conditions such as temperature, humidity and precipitation influences the vector borne diseases (Curtin and Aronson, 2021;Karimi et al, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017). Leishmania vector sand flies require increased temperature for the development and survival.…”

“…Leishmania vector sand flies require increased temperature for the development and survival. Thus, they may not tolerate freezing over winter (Curtin and Aronson, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017). The top six burden countries with Cutaneous leishmaniasis cases were recorded in Guatemala, Syria, Iran, Cameroon, Iraq, and Tajikistan (Karimi et al, 2021;Scheufele et al, 2020;Curtin and Aronson, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017).…”

“…Thus, they may not tolerate freezing over winter (Curtin and Aronson, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017). The top six burden countries with Cutaneous leishmaniasis cases were recorded in Guatemala, Syria, Iran, Cameroon, Iraq, and Tajikistan (Karimi et al, 2021;Scheufele et al, 2020;Curtin and Aronson, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017). Furthermore, 70% of Cutaneous leishmaniasis cases were occurred in Afghanistan, Algeria, Brazil, Colombia, Costa Rica, Ethiopia, Palestine, Iran, Sudan, and the Syrian Arab Republic (Karimi et al, 2021;Maarouf and Abdlwahab, 2021;Torres-Guerrero et al, 2017;Mann et al, 2021).…”

“…In Mexico, the most characteristic form is the cutaneous-chondral form, also called -chiclero's ulcer‖ which when affecting the ear cause the classic chiclero's ulcer (gum tree harvester's ulcer) (Torres-Guerrero et al, 2017). Leishmaniasis (Mundinia) martiniquensis in the Caribbean, Leishmaniasis amazonensis and Leishmaniasis waltoni as a cause of autocthonous Cutaneous leishmaniasis in the Dominican Republic, Guadelupe, Martinique, Grenada, and Trinidad and Tobago (Curtin and Aronson, 2021;McIlwee et al, 2018;Wright et al, 2008;Stahlman et al, 2017).…”