infectious diseases
Leishmaniasis
Diagnosis of Leishmaniasis
Light microscopy of Wright-Giemsa or Giemsa-stained tissue samples, touch preparations, or aspirates Antibody titers for visceral leishmaniasis, but not for cutaneous or mucosal leishmaniasis Culture (special media required) Polymerase chain reaction–based assays Parasites are usually difficult to find or isolate in culture from biopsies of mucosal lesions. Organisms causing simple cutaneous leishmaniasis can be differentiated from those capable of causing mucosal leishmaniasis based on the geographic area of acquisition, specific DNA probes, or analysis of cultured parasites. Serologic tests can help diagnose visceral leishmaniasis; high titers of antibodies to a recombinant leishmanial antigen (rk39) are present in most immunocompetent patients with visceral leishmaniasis. But antibodies may be absent in patients with AIDS or other immunocompromising conditions. Serologic tests for antileishmanial antibodies are not helpful in the diagnosis of cutaneous leishmaniasis. Polymerase chain reaction (PCR)–based assays of aspirates from bone marrow, the spleen, or lymph nodes in patients with visceral leishmaniasis or of biopsy, aspirates, or touch preparations from a skin lesion help diagnose leishmaniasis. The leishmanin skin test that detects a delayed-type hypersensitivity response to leishmanial antigens is not available in the US. It is typically positive in patients with cutaneous and mucosal leishmaniasis but negative in those with active visceral leishmaniasis. 