Rising Dewpoint Temperature and Mosquito-Borne Disease in the Caribbean

Abstract The sensitivity of mosquito-borne disease in Puerto Rico is studied in relation to dewpoint temperature Td, wind velocity, and other climate fields across the Caribbean since 1979. Weekly reported clinically diagnosed cases, largely contributed by dengue, are analyzed for the seasonal cycle that crests from July to October. Monthly clinically diagnosed cases are summed into annual statistics for comparison with dewpoint temperature assimilated by the European Reanalysis v5. Correlation mapping illustrates that annually summed case numbers in Puerto Rico tend to spike at 3–6-yr intervals when dewpoint temperatures are above normal in spring and cloud fraction is below normal in late summer. Statistical analysis with tropical east Pacific sea surface temperatures indicates that high case numbers or epidemics follow 6–9 months after El Niño. Composite atmospheric circulations were mapped for the top 10 years with high case numbers, and sharp spatial gradients of coastal Td and wind were analyzed to explain how capital cities experience localized outbreaks. Long-term trends in dewpoint temperature are markedly upward at +0.2°C yr −1 , and the 22°C Td threshold has surrounded the Antilles Islands under the influence of global warming. Mosquito-borne virus infections are likely to increase in the future, but the statistical outcomes reported here make it possible to anticipate epidemics and constrain health impacts.