Variability in Malaria Parasite Density Measurements by Microscopy
Author Information
Author(s): Wendy Prudhomme O'Meara, Mazie Barcus, Chansuda Wongsrichanalai, Sinuon Muth, Jason D Maguire, Robert G Jordan, William R Prescott, F Ellis McKenzie
Primary Institution: Fogarty International Center, National Institutes of Health
Hypothesis
How does reader technique contribute to discrepancies in measurements of malaria parasite density?
Conclusion
Errors in microscopy measurements can lead to serious consequences for efficacy trials, including potentially abandoning promising vaccine candidates.
Supporting Evidence
- Standard deviations of parasite density readings ranged from 30% to 250% of the mean.
- The number of white blood cells indexed significantly contributed to discrepancies among microscopists.
- Errors in microscopy measurements can lead to abandoning promising vaccine candidates.
Takeaway
Different people looking at the same blood samples can see different amounts of malaria parasites, which can cause big problems in testing new medicines.
Methodology
24–27 expert microscopists independently read 895 slides from 35 blood donations to analyze discrepancies in parasite density measurements.
Potential Biases
Differences in reader technique and judgment could introduce variability in results.
Limitations
The study did not account for differences between slides prepared from the same blood sample due to handling and preparation.
Participant Demographics
Participants included symptomatic patients from regional health clinics in Cambodia and Indonesia.
Statistical Information
P-Value
0.0096
Statistical Significance
p = 0.0096
Digital Object Identifier (DOI)
Want to read the original?
Access the complete publication on the publisher's website