Laboratory Diagnosis of Cutaneous and Visceral Leishmaniasis: Current and Future Methods

Abstract

Leishmaniasis is a neglected tropical disease with two main clinical forms: cutaneous and visceral leishmaniasis. Diagnosis of leishmaniasis is still a challenge, concerning the detection and correct identification of the species of the parasite, mainly in endemic areas where the absence of appropriate resources is still a problem. Most accessible methods for diagnosis, particularly in these areas, do not include the identification of each one of more than 20 species responsible for the disease. Here, we summarize the main methods used for the detection and identification of leishmaniasis that can be performed by demonstration of the parasite in biological samples from the patient through microscopic examination, by in vitro culture or animal inoculation; by molecular methods through the detection of parasite DNA; or by immunological methods through the detection of parasite antigens that may be present in urine or through the detection of specific antibodies against the parasite. Potential new methods that can be applied for laboratory diagnosis of leishmaniasis are also discussed.

Molecular Diagnosis of Leishmaniasis: Quantification of Parasite Load by a Real-Time PCR Assay with High Sensitivity

“…Several methods and tools have been developed over recent years for the detection, quantification, and identification of the parasite of the genus Leishmania [ 15 , 19 , 20 , 42 , 43 ]. Although advances in these methods have improved the sensitivity and specificity of leishmaniasis diagnosis, there are still some challenges to be overcome.…”

“…Although advances in these methods have improved the sensitivity and specificity of leishmaniasis diagnosis, there are still some challenges to be overcome. For instance, developing affordable, fast, and accessible tests that can define Leishmania species will be a turning point in diagnosis, since the discrimination of species has significant importance for prognosis and species-specific treatments [ 20 ]. Parasitological and microscopic examinations are broadly used; although highly specific, they present insufficient sensitivity and do not provide Leishmania species identification [ 19 , 20 ].…”

“…Clinical status and a positive immunological test can be prognostic, but the diagnostic ‘gold standard’ is parasite identification by isolation on a specific culture medium [ 18 , 19 ]. Moreover, microscopic examination of tissue biopsy specimens, bone marrow, or splenic aspirates, are important to help the diagnostic approach [ 10 , 18 , 19 , 20 ]. Each of these diagnostic techniques has advantages and shortcomings, and the diagnostic methods should be selected in light of these considerations.…”

The Geographical Distribution of Human Cutaneous and Visceral Leishmania Species Identified by Molecular Methods in Iran: A Systematic Review With Meta-Analysis

“…Currently, molecular approaches are used for species identification, genotyping, and determine polymorphisms in Leishmania parasites (175). In most cases, these methods have replaced the isoenzyme method, which is the standard method for determining the species and strain of the Leishmania parasite (176).…”

Perfil científico e tecnológico do diagnóstico, tratamento e proteção vacinal para leishmaniose visceral / Scientific and technological profile of diagnosis, treatment and vaccine protection for visceral leishmaniasis

“…Outras opções diagnósticas são os testes sorológicos, mas estes apresentam reação cruzada com outras DTN, como a doença de chagas. Já os testes moleculares, ainda são de elevado custo financeiro, sendo difícil sua aplicação em áreas endêmicas (CABALLERO et al, 2007;REIMÃO et al, 2020). Assim, o desenvolvimento de insumos para prevenção, diagnóstico e tratamento da LV ainda são necessários para eliminar esta DNT e promover a recuperação de indivíduos infectados.…”