Jury, M., 2008: Climate influences on dengue epidemics in Puerto
Rico. Int. J. Environ. Health Res., 18, 323–334.
Abstract:
The variability of the insect-borne disease dengue in Puerto Rico was studied in relation
to climatic variables in the period 1979–2005. Annual and monthly reported dengue
cases were compared with precipitation and temperature data. Results show that the
incidence of dengue in Puerto Rico was relatively constant over time despite global
warming, possibly due to the offsetting effects of declining rainfall, improving health
care and little change in population. Seasonal fluctuations of dengue were driven by
rainfall increases from May to November. Year-to-year variability in dengue cases was
positively related to temperature, but only weakly associated with local rainfall and an
index of El Nin˜ o Southern Oscillation (ENSO). Climatic conditions were mapped with
respect to dengue cases and patterns in high and low years were compared. During
epidemics, a low pressure system east of Florida draws warm humid air over the
northwestern Caribbean. Long-term trends in past observed and future projected
rainfall and temperatures were studied. Rainfall has declined slowly, but temperatures
in the Caribbean are rising with the influence of global warming. Thus, dengue may
increase in the future, and it will be necessary to anticipate dengue epidemics using
climate forecasts, to reduce adverse health impacts.