Estimating drivers of autochthonous transmission of Chikungunya virus in its invasion of the americas
Autor(es): Perkins T Alex, Metcalf C Jessica E, Grenfell Bryan T, Tatem Andrew J
Resumo: Background Chikungunya is an emerging arbovirus that has caused explosive outbreaks in Africa - Asia for decades - invaded the Americas just over a year ago. During this ongoing invasion, it has spread to 45 countries where it has been transmitted autochthonously, infecting nearly 1.3 million people in total. Methods Here, we made use of weekly, country-level case reports to infer relationships between transmission - two putative climatic drivers: temperature - precipitation averaged across each country on a monthly basis. To do so, we used a TSIR model that enabled us to infer a parametric relationship between climatic drivers - transmission potential, - we applied a new method for incorporating a probabilistic description of the serial interval distribution into the TSIR framework. Results We found significant relationships between transmission - linear - quadratic terms for temperature - precipitation - a linear term for log incidence during the previous pathogen generation. The lattermost suggests that case numbers three to four weeks ago are largely predictive of current case numbers. This effect is quite nonlinear at the country level, however, due to an estimated mixing parameter of 0.74. Relationships between transmission - the climatic variables that we estimated were biologically plausible - in line with expectations. Conclusions Our analysis suggests that autochthonous transmission of Chikungunya in the Americas can be correlated successfully with putative climatic drivers, even at the coarse scale of countries - using long-term average climate data. Overall, this provides a preliminary suggestion that successfully forecasting the future trajectory of a Chikungunya outbreak - the receptivity of virgin areas may be possible. Our results also provide tentative estimates of timeframes - areas of greatest risk, - our extension of the TSIR model provides a novel tool for modeling vector-borne disease transmission.
Palavras-Chave: Aedes; Chikungunya; R0; TSIR; Arbovirus; Epidemic; invasion; Mathematical model; Mosquito; Seasonality
Imprenta: PLoS Currents, v. 7, 2015
Identificador do objeto digital: 10.1371/currents.outbreaks.a4c7b6ac10e0420b1788c9767946d1fc
Descritores: Chikungunya virus - Arbovirus ; Chikungunya Virus - Virus ; Chikungunya virus - Transmission ; Chikungunya virus - Epidemic
Data de publicação: 2015
