Sources of variability in determining malaria parasite density by microscopy.

Journal Article (Journal Article)

Enumeration of parasites by microscopic examination of blood smears is the only method available for quantifying parasitemia in infected blood. However, the sources and scale of error inherent in this technique have not been systematically investigated. Here we use data collected in outpatient clinics in Peru and Thailand to elucidate important sources of variation in parasite density measurements. We show that discrepancies between readings from two independent microscopists and multiple readings from a single microscopist are inversely related to the density of the infection. We present an example of how differences in reader technique, specifically the number of white blood cells counted, can contribute to the differences between readings. We discuss the implications of this analysis for field studies and clinical trials.

Full Text

Duke Authors

Cited Authors

  • O'Meara, WP; McKenzie, FE; Magill, AJ; Forney, JR; Permpanich, B; Lucas, C; Gasser, RA; Wongsrichanalai, C

Published Date

  • September 2005

Published In

Volume / Issue

  • 73 / 3

Start / End Page

  • 593 - 598

PubMed ID

  • 16172488

Pubmed Central ID

  • PMC2500224

International Standard Serial Number (ISSN)

  • 0002-9637


  • eng

Conference Location

  • United States