A new model developed by Stanford researchers suggests the optimal temperature for the spread of mosquito-borne diseases may be 84 degrees Fahrenheit. The researchers hope to use their new tool to forecast how disease transmission is affected by climate change.
The researchers, led by biologist Erin Mordecai, PhD, examined the spread of Zika, dengue and chikungunya, which are all spread by mosquitoes. As a Stanford release explains:
Temperature controls several factors that underlie the time it takes for a virus to be transmittable to humans. These include how long it takes for a mosquito to ingest a virus during one feeding and then be ready to inject it in a later feeding; the length of the mosquito’s life cycle; and how often mosquitoes bite.
'All these traits rely on temperature, but they tend to be nonlinear,' Mordecai said. 'They increase to a point and then drop off.' ...
She said that if you graph how transmission rates change with temperature, you get a bell-shaped curve peaking at 29 degrees C [84 degrees Fahrenheit].
Other models have proposed higher optimum temperatures, which would indicate that transmission will increase as some regions grow warmer with climate change. But Mordecai's model suggests that if a region is already averaging around 84 degrees, higher temperatures will reduce transmission. The release adds:
The information can also help predict how and where disease might spread with climate change. 'We really want to build more predictive models that take climate information and make predictions about when and where we can invest in vector control to try to prevent epidemics,' Mordecai said.
The research appears in PLoS Neglected Tropical Diseases.
Previously: How cellphones might help researchers battle mosquito-spread disease, Keeping mosquitoes in check to prevent widespread disease and Stanford undergraduate class authors paper on Zika
Photo by Dany Krom
