Thermal thresholds heighten sensitivity of West Nile virus transmission to changing temperatures in coastal California
journal contribution
posted on 2020-11-17, 00:00authored byAlexander Gershunov, Christopher M. Hoover, Dennis P. Lettenmaier, Jason R RohrJason R Rohr, Jennifer R. Head, Justin V. Remais, Nicholas K. Skaff, Philip A. Collender, Qu Cheng, Rachel E. S. Clemesha, Robert E. Snyder
Temperature is widely known to influence the spatio-temporal dynamics of vector-borne disease transmission, particularly as temperatures vary across critical thermal thresholds. When temperature conditions exhibit such 'transcritical variation', abrupt spatial or temporal discontinuities may result, generating sharp geographical or seasonal boundaries in transmission. Here, we develop a spatio-temporal machine learning algorithm to examine the implications of transcritical variation for West Nile virus (WNV) transmission in the Los Angeles metropolitan area (LA). Analysing a large vector and WNV surveillance dataset spanning 2006-2016, we found that mean temperatures in the previous month strongly predicted the probability of WNV presence in pools ofCulex quinquefasciatusmosquitoes, forming distinctive inhibitory (10.0-21.0 degrees C) and favourable (22.7-30.2 degrees C) mean temperature ranges that bound a narrow 1.7 degrees C transitional zone (21-22.7 degrees C). Temperatures during the most intense months of WNV transmission (August/September) were more strongly associated with infection probability inCx. quinquefasciatuspools in coastal LA, where temperature variation more frequently traversed the narrow transitional temperature range compared to warmer inland locations. This contributed to a pronounced expansion in the geographical distribution of human cases near the coast during warmer-than-average periods. Our findings suggest that transcritical variation may influence the sensitivity of transmission to climate warming, and that especially vulnerable locations may occur where present climatic fluctuations traverse critical temperature thresholds.
History
Date Created
2020-08-12
Date Modified
2020-11-17
Language
English
Rights Statement
All rights reserved.
Publisher
Proceedings Of The Royal Society B-Biological Sciences