False Positives in Malaria Testing
Author Information
Author(s): Durnez Lies, Van Bortel Wim, Denis Leen, Roelants Patricia, Veracx Aurélie, Trung Ho Dinh, Sochantha Tho, Coosemans Marc
Primary Institution: Institute of Tropical Medicine, Department of Parasitology, Belgium
Hypothesis
The study aims to estimate the level of false positivity among different anopheline species in Cambodia and Vietnam and to check for the presence of other parasites that might interact with the anti-CSP monoclonal antibodies.
Conclusion
The CSP-ELISA can considerably overestimate the entomological inoculation rate, particularly for P. falciparum and for zoophilic species.
Supporting Evidence
- 88% of mosquitoes positive for P. falciparum CSP-ELISA were confirmed negative by PCR.
- False positive results were associated with zoophilic mosquito species.
- The heat-unstable cross-reacting antigen was mainly present in the head and thorax of false positive specimens.
Takeaway
Sometimes tests for malaria can say a mosquito is infected when it's not, especially if the mosquito usually bites animals instead of people.
Methodology
Mosquitoes were collected in Cambodia and Vietnam, tested for sporozoites using CSP-ELISA, and confirmed by Plasmodium specific PCR.
Potential Biases
False positives were mainly observed in zoophilic mosquito species.
Limitations
The study did not identify the source of the cross-reacting antigen causing false positives.
Participant Demographics
Mosquitoes collected from various regions in Cambodia and Vietnam.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.001
Digital Object Identifier (DOI)
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