Sources of Error in the Estimation of Mosquito Infection Rates Used to Assess Risk of Arbovirus Transmission

Dulce M. Bustamante Florida Medical Entomology Laboratory, Department of Entomology and Nematology, University of Florida, Vero Beach, Florida

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Cynthia C. Lord Florida Medical Entomology Laboratory, Department of Entomology and Nematology, University of Florida, Vero Beach, Florida

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Infection rate is an estimate of the prevalence of arbovirus infection in a mosquito population. It is assumed that when infection rate increases, the risk of arbovirus transmission to humans and animals also increases. We examined some of the factors that can invalidate this assumption. First, we used a model to illustrate how the proportion of mosquitoes capable of virus transmission, or infectious, is not a constant fraction of the number of infected mosquitoes. Thus, infection rate is not always a straightforward indicator of risk. Second, we used a model that simulated the process of mosquito sampling, pooling, and virus testing and found that mosquito infection rates commonly underestimate the prevalence of arbovirus infection in a mosquito population. Infection rate should always be used in conjunction with other surveillance indicators (mosquito population size, age structure, weather) and historical baseline data when assessing the risk of arbovirus transmission.

Author Notes

*Address correspondence to Dulce M. Bustamante, Escuela de Biologia, Universidad de San Carlos, Edificio T-10 2do Nivel, Ciudad Universitaria, Zona 12, Guatemala City, Guatemala. E-mail: dulce_mariab@hotmail.com

Financial support: This study was supported by the National Institutes of Health (grant AI42164).

Authors' addresses: Dulce M. Bustamante, Escuela de Biologia, Universidad de San Carlos, Ciudad Universitaria, Guatemala City, Guatemala, E-mail: dulce_mariab@hotmail.com. Cynthia C. Lord, Florida Medical Entomology Laboratory, Department of Entomology and Nematology, University of Florida, Vero Beach, FL, E-mail: clord@ufl.edu.

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