Table 2.

Diagnostic methods

Disease pattern	Direct vs indirect	Diagnostic method	Comments
Cutaneous leishmaniasis	Direct	Biopsy, scraping, aspirate	Sensitivity dependent on expertise of pathologist and quality of specimen. Obtain from edge of ulcer and base
		Microscopy	Giemsa stained microscopy
		Culture	Amastigote typically 2–4 μm in diameter, round to oval in shape with nucleus and kinetoplast
		Histology	Special media, as organism is fastidious it can take weeks to become positive.
		PCR	Most sensitive, identifies species which is helpful in excluding ML associated species. PCR is also helpful in cases with low parasite burden.
	Indirect	CL Detect	Immunochromatographic assay for the rapid detection of Leishmania species antigen in ulcerative skin lesions
			Sensitivity 96%, specificity 90%
		Serologic tests (see below)	Not recommended for diagnosis of CL
Visceral leishmaniasis	Direct	Splenic aspirate (parasite isolation, culture, histology, and PCR per above)	Most sensitive (93–99%) compared to bone marrow and lymph node aspirate for diagnosing VL but risk of splenic hemorrhage
		Bone marrow aspirate	Bone marrow sensitivity (52–85%) sensitivity.
			Safer to perform than splenic aspirate
		LN Aspirate	Lymph node aspirate sensitivity (52%–58%)
		Peripheral blood	Assess blood for buffy coat, in vitro culture, and molecular analyses. Helpful in diagnosis for immunocompromised and HIV
	Indirect	Serological tests:	Cannot distinguish active from prior infection. Not helpful for CL. Often non-reactive in immunocompromised hosts.
		Rapid Diagnostic Test (rK-39)*	Detect specific antibody against antigen present in L. donovani, chagasi-infantum
			Results available in 20–25 min
			Easy to perform, quick and cheap- particularly helpful in underserved areas
			Sensitivity varies depending on region and parasite species
			Can cross react with other infections—for example Chagas disease
		Direct Agglutination Test (DAT)*	Uses whole organisms to look for antibody.
			Gives antibody tires ranging from 1:100 up to 1: 151200.
			Sensitive (>95%) and specific (>85%) test when performed correctly
			Needs well trained technician to perform over 2-3 days
			Not available in North America
		Other antibody test, ELISA, Indirect immunofluorescence, indirect agglutination test, antigen test	Serologic antigen and urine antigen available
			Sensitivity and specificity varies based on test
			False positive results in persons with Chagas, leprosy, tuberculosis, malaria
Mucosal leishmaniasis	Direct	Biopsy, scraping, aspirate of mucosal lesion/LN (culture, histology, and PCR per above)	Direct diagnosis is preferred.
	Indirect	Serological tests per above	Not as helpful for ML as for VL. Direct diagnosis is preferred
		Leishmanin Test	Delayed type hypersensitivity response
			Also known as Montenegro test, works similarly to tuberculin skin test
			Most useful in diagnosis of ML
			Negative in diffuse CL, active VL
			False positives with other skin disease
			Not available in North America

CL, cutaneous leishmaniasis; ML, mucosal leishmaniasis; VL, visceral leishmaniasis; LN, lymph node

*Most common serological tests

Adapted from Aronson et al. CID, PAHO, Burza et al., Berman et al.