Field validity, reproducibility and feasibility of diagnostic tests for visceral leishmaniasis in rural Nepal

Trop Med Int Health. 2006 Jan;11(1):31-40. doi: 10.1111/j.1365-3156.2005.01533.x.


Objectives: To assess the field accuracy, reproducibility and feasibility of the formol gel test (FGT), the urine latex agglutination test (KAtex) and a rK39 antigen-based dipstick for the diagnosis of visceral leishmaniasis (VL) in rural Nepal.

Method: Patients with clinical suspicion of VL were recruited at Rangeli District Hospital (DH), a 15-bed government hospital located in south-eastern Nepal. FGT, KAtex and rK39 dipstick tests were performed on site and later repeated at a reference kala-azar diagnostic laboratory to assess reproducibility. Diagnosis of VL was confirmed by either a positive bone marrow aspirate examination or a positive direct agglutination test (DAT titre > or = 1:3200) in patients who later responded to anti-leishmanial therapy.

Results: Of 155 patients initially recruited, 142 (85 with VL and 57 with another diagnosis) were included in the study. The sensitivity of the rK39 dipstick [89%; 95% confidence interval (CI): 81-94] was significantly higher than that of the KAtex (57%; 95% CI: 46-67) and the FGT (52%; 95% CI: 41-62). All three tests had a specificity of at least 90%. Agreement was higher for the rK39 dipstick (kappa = 0.87) than for the FGT (0.68) and the KAtex (0.43). All tests required < or = 20 min of actual work and < or = 40 min to obtain the results.

Conclusion: The rK39 dipstick was easy to do, more accurate and reproducible than other rapid diagnostic tests for VL in a DH of rural Nepal. It should be integrated into the field diagnostic algorithm of VL in this region and mechanisms to secure its availability should be found.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antigens, Protozoan / analysis
  • Diagnostic Tests, Routine / methods*
  • Disinfectants
  • Endemic Diseases
  • Feasibility Studies
  • Female
  • Formaldehyde
  • Humans
  • Immunologic Tests / methods
  • Latex Fixation Tests / methods
  • Leishmaniasis, Visceral / complications
  • Leishmaniasis, Visceral / diagnosis*
  • Leishmaniasis, Visceral / epidemiology
  • Male
  • Nepal / epidemiology
  • Reproducibility of Results
  • Rural Health
  • Sensitivity and Specificity


  • Antigens, Protozoan
  • Disinfectants
  • Formaldehyde