Seasonality of rotavirus disease in the tropics: a systematic review and meta-analysis.
BACKGROUND
To date little conclusive evidence exists on the seasonality of rotavirus incidence in the tropics. We present a systematic review and meta-analysis on the seasonal epidemiology of rotavirus in the tropics, including 26 studies reporting continuous monthly rotavirus incidence for which corresponding climatological data was available.


METHODS
Using linear regression models that account for serial correlation between months, monthly rotavirus incidence was significantly negatively correlated with temperature, rainfall and relative humidity in 65%, 55% and 60% of studies, respectively. We carried out pooled analyses using a generalized estimating equation (GEE) that accounts for correlation from between-study variation and serial correlation between months within a given study.


RESULTS
For every 1 degrees C (1.8 degrees F) increase in mean temperature, 1 cm (0.39 in.) increase in mean monthly rainfall, and 1% increase in relative humidity (22%) this analysis showed reductions in rotavirus incidence of 10% (95% CI: 6-13%), 1% (95% CI: 0-1%), and 3% (95% CI:0-5%), respectively.


CONCLUSIONS
On the basis of the evidence, we conclude that rotavirus responds to changes in climate in the tropics, with the highest number of infections found at the colder and drier times of the year.
Levy
Karen
K
Department of Environmental Science, University of California, Berkeley, USA. karenlev@umich.edu
Hubbard
Alan E
AE
Eisenberg
Joseph N S
JN
D003967:Diarrhea / Q000453:epidemiology* / Q000821:virology*; D006801:Humans; D006813:Humidity; D015994:Incidence; D016014:Linear Models; D011891:Rain; D012307:Risk Factors; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000635:transmission; D012621:Seasons; D013696:Temperature; D014329:Tropical Climate