Skip to Main content Skip to Navigation
Journal articles

Measuring malaria morbidity in an area of seasonal transmission: Pyrogenic parasitemia thresholds based on a 20-year follow-up study

Abstract : Asymptomatic carriage of P. falciparum is frequent in areas endemic for malaria and individual diagnosis of clinical malaria attacks is still difficult. We investigated the impact of changes in malaria endemicity on the diagnostic criteria for malaria attacks in an area of seasonal malaria transmission. METHODS: We analyzed the longitudinal data collected over 20 years from a daily survey of all inhabitants of Ndiop, a rural community in central Senegal, in a logistic regression model to investigate the relationship between the level of Plasmodium falciparum parasitemia and the risk of fever, with the aim of determining the best parasitemia thresholds for attributing to malaria a fever episode. RESULTS: A total of 34,136 observations recorded from July 1993 to December 2013 from 850 individuals aged from 1 day to 87 years were included. P. falciparum asymptomatic carriage declined from 36% to 1% between 1993 and 2013. A total of 9,819 fever episodes were associated with a positive blood film for P. falciparum. Using age-dependent parasitemia thresholds for attributing to malaria a fever episode, we recorded 6,006 malaria attacks during the study period. Parasitemia thresholds seemed to be lower during the low-to-zero transmission season and tended to decrease with changes in control policies. The number of clinical malaria attacks was overestimated for all age groups throughout the study when all fever episodes associated with P. falciparum parasitemia were defined as malaria attacks. CONCLUSION: Pyrogenic thresholds are particularly sensitive to changes in malaria epidemiology and are therefore an interesting tool to accurately assess the burden of malaria in the context of declining transmission.
Complete list of metadatas

Cited literature [30 references]  Display  Hide  Download

https://hal-amu.archives-ouvertes.fr/hal-02508073
Contributor : Isabelle Combe <>
Submitted on : Tuesday, March 17, 2020 - 4:58:07 PM
Last modification on : Tuesday, March 24, 2020 - 1:40:59 AM
Long-term archiving on: : Thursday, June 18, 2020 - 3:08:51 PM

File

Measuring_malaria_morbidity_in...
Publication funded by an institution

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

Marion Dollat, Cheikh Talla, Cheikh Sokhna, Fatoumata Diene Sarr, Jean-Francois Trape, et al.. Measuring malaria morbidity in an area of seasonal transmission: Pyrogenic parasitemia thresholds based on a 20-year follow-up study. PLoS ONE, Public Library of Science, 2019, 14 (6), pp.e0217903. ⟨10.1371/journal.pone.0217903⟩. ⟨hal-02508073⟩

Share

Metrics

Record views

327

Files downloads

766