Malaria Lab Sesssion

COL Art Lyons, PhD,MDFebruary 26, 2014Fort Riley Trop. Med. CourseMalaria Lab SessionHelpful Reference:WHO Health Library for Disastershttp://helid.digicollection.org/enSearch for malariaBasic Malaria Microscopy Learners Guidehttp://whqlibdoc.who.int/publications/2010/9789241547826_eng.pdf

Blood Smear for malariaThick FilmThin FilmRed blood cells layered 10-20 times thicker v. thin filmRed Cells are not fixed (staining caused lysis) thus the parasites are within red cell ghostsCan evaluate large amount of red blood cellsSensitive (negative more likely to rule out malaria) Single layer of red blood cellsFixed with methanolUsed to identify parasite species.Used to estimate parasitemiaView after thick smearSpecific STAINING: http://www.dpd.cdc.gov/dpdx/HTML/PDF_Files/malaria_staining_benchaid.pdfChromatic = redCytoplasm = blueDont see both = Not malaria

Key Morphological Differences Between HumanPlasmodiumSpecies in Blood SmearsP. falciparumP. vivaxP. ovaleP. malariaenumerous rings

smaller rings

NO trophozoites or schizonts seen

cresent-shaped gametocytesenlarged erythrocyte(younger cells)

Schffner's dots diffuse and fine

'ameboid' trophozoitesimilar toP. vivax

compact trophozoite

fewer merozoites in schizont

Elongated, erythrocytecompact parasite

merozoites in rosette

P. falciparum

P. vivax

Giemsa Schuffners dots

P. ovale

Coarse PigmentCompact troph. P. malariae

Unlike Vivax, Not EnlargedThe End