Direct detection of Leishmania from clinical samples
John N Waitumbi1, Joshua Bast, Nancy Nyakoe
1Kenya Medical Research Institute/US Army Medical Research Unit, Kenya.
U.S. Army Medical Department Journal
|May 17, 2017
Summary
Rapid polymerase chain reaction (PCR) assays show promise for diagnosing leishmaniasis. These field-expedient tests accurately detect Leishmania parasites in patient samples, aiding military health priorities.
Area of Science:
- Medical diagnostics
- Parasitology
- Molecular biology
Background:
- Leishmaniasis diagnosis is critical, especially for military personnel.
- Existing diagnostic methods may lack the speed and accuracy required for field deployment.
- Polymerase chain reaction (PCR) assays offer potential for rapid and sensitive detection.
Purpose of the Study:
- To evaluate the diagnostic sensitivity and specificity of field-expedient Leishmania genus and visceral Leishmania-specific TaqMan PCR assays.
- To assess the utility of these assays for direct detection of Leishmania in clinical samples.
Main Methods:
- Testing of blood samples from patients with confirmed visceral leishmaniasis and healthy controls in Kenya.
- Evaluation of Leishmania genus and visceral Leishmania-specific TaqMan PCR assays.
- Analysis of skin scrape samples from cutaneous leishmaniasis patients in Honduras.
Main Results:
- Leishmania genus assay demonstrated 100% sensitivity in Kenyan samples and 100% in Honduran samples.
- Visceral Leishmania assay showed 93% sensitivity and 80% specificity in Kenyan blood samples.
- Visceral Leishmania assay achieved 100% specificity with Honduran cutaneous leishmaniasis samples.
Conclusions:
- Field-expedient TaqMan PCR assays are promising for rapid, sensitive, and specific direct detection of Leishmania in clinical samples.
- These molecular diagnostic tools could significantly improve leishmaniasis diagnosis in resource-limited settings.
- The assays show potential for military applications requiring swift and accurate disease identification.
Related Concept Videos
01:25Rapid Identification of Pathogens
MALDI-TOF MS has transformed clinical microbiology by offering a rapid and reliable method for pathogen identification. The traditional approach to microbial identification typically involves time-consuming culture techniques and biochemical tests, which can delay the initiation of appropriate antimicrobial therapy. MALDI-TOF MS avoids these delays by using characteristic ribosomal protein mass patterns of microbial cells, enabling accurate species-level identification within minutes.Principle...
01:30Leishmaniasis
Leishmaniasis is a protozoal disease caused by species of the genus Leishmania and transmitted through the bite of infected female sandflies. The parasite exists in two principal morphological forms during its life cycle. A sandfly acquires intracellular amastigotes from an infected reservoir host, such as a dog. Within the sandfly, these forms differentiate into motile, flagellated promastigotes. During a subsequent blood meal, promastigotes are injected into the human host, where they...
01:21Antiprotozoal Agents
Leishmaniasis is a widespread parasitic disease caused by several Leishmania species. It affects millions of people each year and remains a major public health problem in endemic regions. First-line treatment relies on pentavalent antimonials, including meglumine antimoniate and sodium stibogluconate. Even so, how these drugs work has not been fully clear, especially their interaction with parasite-specific biochemical pathways. One key target is trypanothione reductase (TR), an enzyme that...