Simulation models predict that school-age children are responsible for most human-to-mosquito Plasmodium falciparum transmission in southern Malawi
AuthorCoalson, Jenna E.
Cohee, Lauren M.
Buchwald, Andrea G.
Seydel, Karl B.
Taylor, Terrie E.
Laufer, Miriam K.
Wilson, Mark L.
AffiliationUniv Arizona, Ctr Insect Sci, Tucson, AZ 85721 USA
Univ Arizona, Dept Epidemiol & Biostat, Tucson, AZ 85721 USA
MetadataShow full item record
PublisherBIOMED CENTRAL LTD
CitationCoalson et al. Malar J (2018) 17:147 https://doi.org/10.1186/s12936-018-2295-4
Rights© The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractBackground: Malaria persists in some high-transmission areas despite extensive control efforts. Progress toward elimination may require effective targeting of specific human populations that act as key transmission reservoirs. Methods: Parameterized using molecular-based Plasmodium falciparum infection data from cross-sectional community studies in southern Malawi, a simulation model was developed to predict the proportions of human-to-mosquito transmission arising from (a) children under 5 years old (U5s), (b) school-age children (SAC, 5-15 years), (c) young adults (16-30 years), and (d) adults > 30 years. The model incorporates mosquito biting heterogeneity and differential infectivity (i.e. probability that a blood-fed mosquito develops oocysts) by age and gametocyte density. Results: The model predicted that SAC were responsible for more than 60% of new mosquito infections in both dry and rainy seasons, even though they comprise only 30% of this southern Malawi population. Young adults were the second largest contributors, while U5s and adults over 30 were each responsible for < 10% of transmission. While the specific predicted values are sensitive to the relative infectiousness of SAC, this group remained the most important contributor to mosquito infections under all realistic estimates. Conclusions: These results suggest that U5 children play a small role compared to SAC in maintaining P. falciparum transmission in southern Malawi. Models that assume biting homogeneity overestimate the importance of U5s. To reduce transmission, interventions will need to reach more SAC and young adults. This publicly available model can be used by others to estimate age-specific transmission contributions in epidemiologically similar sites with local parameter estimates of P. falciparum prevalence and bed net use.
NoteOpen access journal.
VersionFinal published version
SponsorsNational Institute of Allergy and Infectious Diseases (NIAID) [U19AI089683, R21AI107421]; National Institute of General Medical Sciences (NIGMS) at the National Institutes of Health (NIH) [K12 GM000708]