Validation of in-house liquid direct agglutination test antigen: the potential diagnostic test in visceral Leishimaniasis endemic areas of Northwest Ethiopia

BMC Microbiol. 2020 Apr 15;20(1):90. doi: 10.1186/s12866-020-01780-0.

Abstract

Background: Visceral leishmaniasis in Ethiopia is a re-emerging threat to public health, with increased geographical distribution and number of cases. It is a fatal disease without early diagnosis and treatment; thus, the availability of affordable diagnostic tools is crucial. However, due to delays caused by import regulations, procurement and late delivery of imported test kits, accessibility remains a problem in the control program. Therefore, we aimed to produce and evaluate the performance of an in-house liquid (AQ) direct agglutination test (DAT) antigen.

Result: The AQ-DAT was produced at the Armauer Hansen Research Institute, using Leishmania donovani strain (MHOM/ET/67/L82). Sera from 272 participants; 110 microscopically confirmed cases of VL, 76 apparently healthy and 86 patients who had infectious disease other than VL were tested with AQ-DAT, and standard kits: Freeze-dried DAT (FD-DAT) and rK39. Taking microscopy as a gold standard; the sensitivity and specificity of the AQ-DAT were 97.3 and 98.8%, respectively. It had high degrees of agreement (k > 0.8), with a significant (P < 0.05) correlation compared to microscopy, FD-DAT, and rK39.

Conclusion: Although further standardization is required, the in-house AQ-DAT could improve diagnostic accessibility, minimize intermittent stock outs and strengthen the national VL control program.

Keywords: Liquid direct agglutination test; North West Ethiopia; Visceral leishmaniasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Agglutination Tests / methods*
  • Antibodies, Protozoan / blood*
  • Antigens, Protozoan / immunology*
  • Diagnostic Tests, Routine
  • Endemic Diseases
  • Ethiopia / epidemiology
  • Female
  • Humans
  • Leishmania donovani / immunology*
  • Leishmaniasis, Visceral / diagnosis*
  • Leishmaniasis, Visceral / immunology
  • Male
  • Middle Aged
  • Sensitivity and Specificity
  • Young Adult

Substances

  • Antibodies, Protozoan
  • Antigens, Protozoan