From the Guidelines
Diagnosis of Leishmaniasis The diagnosis of leishmaniasis should be based on a combination of clinical presentation, laboratory tests, and sometimes imaging studies, with a focus on demonstrating the parasite through microscopic examination, molecular detection, or serologic testing 1.
Diagnostic Approaches
- Microscopic Examination: Giemsa-stained smears from skin lesions, bone marrow, or spleen aspirates can directly visualize the parasites, confirming the diagnosis 1.
- Molecular Tests: PCR (polymerase chain reaction) can be performed on tissue samples to identify the species of Leishmania, and is considered the most sensitive test currently available 1.
- Serological Tests: These can help in diagnosing visceral leishmaniasis but are less useful for cutaneous leishmaniasis, and should not be used as the sole diagnostic assay, especially in immunocompromised patients 1.
Considerations
- The choice of diagnostic test may depend on the suspected form of leishmaniasis (cutaneous, mucosal, or visceral) and the availability of resources.
- Clinical presentation, including symptoms like skin lesions, fever, weight loss, and splenomegaly, should be considered alongside laboratory findings for an accurate diagnosis.
- It's essential to use multiple diagnostic approaches to maximize the likelihood of a positive Leishmania result, as recommended by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH) 1.
From the Research
Diagnostic Criteria for Leishmaniasis
The diagnostic criteria for Leishmaniasis involve various methods, including:
- Demonstration of the parasites in stained preparations of bone marrow and splenic aspirates, which is considered the gold standard for diagnosis 2
- Serological tests, such as rapid immunochromatographic formats, rK39 in enzyme-linked immune sorbent assay, immunoblotting, and direct agglutination test 2, 3
- Molecular techniques, including polymerase chain reaction (PCR), which is commonly used for diagnosis 2, 4
- Microscopic examination of biological samples from the patient 4
- In vitro culture or animal inoculation 4
- Immunological methods, such as detection of parasite antigens in urine or detection of specific antibodies against the parasite 4
Laboratory Diagnosis
Laboratory diagnosis of Leishmaniasis can be performed using various methods, including:
- Demonstration of the parasite in smears stained with Giemsa stain and on biopsy specimens processed and stained with hematoxylin and eosin stain 5
- Serologic techniques, such as ELISA, IFAT, and Western Blotting 5, 6
- Immunochromatographic tests, such as IT LEISH® and TruQuick IgG/IgM® 6
Serological Tests
Serological tests for the diagnosis of visceral and asymptomatic Leishmaniasis have been compared in various studies, with results showing: