Key points for the laboratory diagnosis of Visceral Leishmaniasis

  1. For a complete laboratory diagnosis, microscopic examinations of Giemsa-stained touch preparations and cultures are recommended, as well as PCR and animal inoculation if available.
  2. Due to potential problems with splenic puncture, bone marrow specimens may be recommended. Although not that productive, examination of buffy coat preparations is recommended prior to more invasive procedure. When collecting blood specimens, remember the diurnal periodicity.
  3. Multiple slides should be prepared for examination from aspirates and/or biopsy specimens

    Morphological form of Leishmania donovani

  4. Tissue imprints or smears should be stained with Giemsa stain (or one of the stains commonly used for blood smears)
  5. Amastigote stages should be found within RE cells or close to disrupted cells.
  6. If cultures are to be performed, specimens must be collected aseptically and control organism cultures should be set up at the same time.
  7. Cultures should be checked weekly for 4 weeks before they are declared negative.
  8. Patients with kala azar have hypergammaglobulinemia; the formal-gel procedure may be helpful.
  9. Serologic tests are helpful, and newer procedures demonstrate increased sensitivity and specificity; this should be considered if parasites cannot be detected in clinical specimens.