Leishmania detection in sand flies using a field-deployable real-time analytic system.

Area of Science:

• Medical Entomology
• Molecular Diagnostics
• Parasitic Diseases

Background:

• Leishmaniasis poses a significant global health challenge, necessitating effective vector surveillance.
• Current diagnostic methods for leishmaniasis vectors can be time-consuming and require specialized laboratory conditions.
• Rapid and accurate detection of Leishmania in sand fly vectors is crucial for timely intervention.

Purpose of the Study:

• To develop and evaluate advanced vector surveillance analytic technologies for real-time leishmaniasis risk assessment.
• To create sensitive and specific polymerase chain reaction (PCR) assays for Leishmania genus and visceral leishmaniasis (VL) causative agents.
• To assess the performance of these assays using field-durable instrumentation.

Main Methods:

• Development of dual fluorogenic-probe hydrolysis (TaqMan) PCR assays targeting Leishmania genus and specific VL agents.
• Utilized thermally stable, freeze-dried reagents for simplified transportation and storage.
• Laboratory testing with diverse Leishmania species and field evaluation using wild sand flies in southern Iraq.

Main Results:

• Laboratory testing showed 100% concordance in sensitivity and specificity with DNA sequencing for both assays.
• Field evaluation in Iraq demonstrated 100% sensitivity and 96% specificity for the Leishmania genus assay.
• The visceral leishmaniasis genotype assay achieved 100% sensitivity and 100% specificity in field conditions.
• Assay preparation and analysis were completed in under 2 hours.

Conclusions:

• Thermally stable PCR assays provide a robust platform for advanced vector surveillance of leishmaniasis.
• These technologies enable real-time risk assessment and simplified diagnostics in resource-limited or field settings.
• The developed assays offer high accuracy and efficiency for detecting Leishmania in sand fly populations.