Blood parasites: Leishmania

4.4 Leishmania diagnosis Microscopy - UKAS accredited test

4.4.1 Microscopy
4.4.2 PCR

Sample requirements: See downloadable sampling notes on the website, address can be found on page one of this document.

Cutaneous Leishmaniasis
• Unstained, fixed aspirate or biopsy impression smears for microscopy.
• Giemsa-stained histology slides.
• Biopsy material in PCR (ATL) buffer (available from the laboratory on request), OR in dry, sterile container OR in 10% ethanol. If a histological wax block of tissue is the only material available please cut 10µm thick wax sections and float onto microscope slides (3/slide, two or 3 slides/sample), send these unstained for DNA extraction. A biopsy should ideally be around the size of a grain of rice.

Visceral leishmaniasis
• THIN marrow smears (please fix for 1 minute in methanol before sending.)
• Marrow /blood in EDTA for PCR -a minimum of 500µl

Key factors affecting test: Use of aspirate, wax block or samples smaller than the size of a grain of rice MAY cause false-negative or insufficient DNA results. The use of Iodine during sampling will inhibit the PCR amplification and may cause false-negative results. The use of Lithium heparin instead of EDTA will inhibit the PCR amplification and may cause false-negative results. Please list travel history with all Leishmania PCR requests.