Widespread atypical cutaneous Leishmaniasis caused by Leishmania (L.) chagasi in Nicaragua

Leishmania chagasi, the causative agent of visceral leishmaniasis (VL) in t he Americas, has recently been associated with atypical cutaneous leishmani asis (ACL) in Central America; however, little comprehensive information ab out this disease is available. Clinical, epidemiologic, and parasitologic c haracteristics of 252 ACL cases and 44 VL cases in Nicaragua were analyzed. Visceral leishmaniasis is primarily associated with malnourished children less than five years of age, whereas ACL is found predominantly in children greater than five years of age and young adults. Genetically similar paras ites are associated with both disease manifestations. The sand fly Lutzomyi a evansi, in addition to Lu. longipalpis, may be involved in transmission o f L. chagasi to humans. Our results indicate that ACL is more prevalent tha n previously thought, affecting up to 10% of a local population. The fact t hat the same parasite appears to cause both ACL and the potentially fatal v isceral disease suggests that the hope immune response is critical in deter mining the outcome of L. chagasi infection. The public health implications of the widespread presence of L. chagasi are discussed.