Detecting the impact of temperature on transmission of Zika, dengue, and chikungunya using mechanistic models

Recent epidemics of Zika, dengue, and chikungunya have heightened the need to understand the seasonal and geographic range of transmission by Aedes aegypti and Ae. albopictus mosquitoes. We use mechanistic transmission models to derive predictions for how the probability and magnitude of transmission for Zika, chikungunya, and dengue change with mean temperature, and we show that these predictions are well matched by human case data. Across all three viruses, models and human case data both show that transmission occurs between 18–34°C with maximal transmission occurring in a range from 26–29°C. Controlling for population size and two socioeconomic factors, temperature-dependent transmission based on our mechanistic model is an important predictor of human transmission occurrence and incidence. Risk maps indicate that tropical and subtropical regions are suitable for extended seasonal or year-round transmission, but transmission in temperate areas is limited to at most three months per year even if vectors are present. Such brief transmission windows limit the likelihood of major epidemics following disease introduction in temperate zones

Correction: Detecting the impact of temperature on transmission of Zika, dengue, and chikungunya using mechanistic models.

[This corrects the article DOI: 10.1371/journal.pntd.0005568.]

Map of predicted temperature suitability for virus transmission by <i>Ae</i>. <i>albopictus</i> and <i>Ae</i>. <i>aegypti</i>.

<p>Color indicates the consecutive months in which temperature is permissive for transmission (predicted <i>R</i>_<i>0</i> > 0) for <i>Aedes</i> spp. transmission based on the minimum likely range (> 97.5% posterior probability that <i>R</i>_<i>0</i> > 0). Black lines indicate the CDC estimated range for the two <i>Aedes</i> spp. in the United States. Model suitability predictions combine temperature mean and 8°C daily variation and are informed by laboratory data (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005568#pntd.0005568.g001" target="_blank">Fig 1</a>, Fig A in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005568#pntd.0005568.s001" target="_blank">S1 Text</a>) and validated against field data (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005568#pntd.0005568.g003" target="_blank">Fig 3</a>).</p

Relative <i>R</i>_<i>0</i> across constant temperatures (°C; top) for <i>Ae</i>. <i>albopictus</i> (light blue) and <i>Ae</i>. <i>aegypti</i> (dark blue), and histograms of the posterior distributions of the critical thermal minimum (bottom left), temperature at peak transmission (bottom middle), and critical thermal maximum (bottom right; all in °C).

<p>Solid lines: mean posterior estimates; dashed lines: 95% credible intervals. <i>R</i>_<i>0</i> curves normalized to a 0–1 scale for ease of comparison and visualization.</p