TY - JOUR
T1 - Indian ocean dipole and rainfall drive a moran effect in east Africa malaria transmission
AU - Chaves, Luis Fernando
AU - Satake, Akiko
AU - Hashizume, Masahiro
AU - Minakawa, Noboru
N1 - Funding Information:
Financial support. This work was funded by the Japan Society for the Promotion of Science and a Nagasaki University Cooperative Research Grant to L. F. C., M. H., and N. M. Research and page charges were covered by Nagasaki University GCOE program on Tropical and Emergent Infectious diseases. L. F. C. is a Gaikokujin Fellow of Japan Society for the Promotion of Science. Potential conflicts of interest. All authors: No reported conflicts.
PY - 2012/6/15
Y1 - 2012/6/15
N2 - Background. Patterns of concerted fluctuation in populations-synchrony-can reveal impacts of climatic variability on disease dynamics. We examined whether malaria transmission has been synchronous in an area with a common rainfall regime and sensitive to the Indian Ocean Dipole (IOD), a global climatic phenomenon affecting weather patterns in East Africa.Methods.We studied malaria synchrony in 5 15-year long (1984-1999) monthly time series that encompass an altitudinal gradient, approximately 1000 m to 2000 m, along Lake Victoria basin. We quantified the association patterns between rainfall and malaria time series at different altitudes and across the altitudinal gradient encompassed by the study locations.Results.We found a positive seasonal association of rainfall with malaria, which decreased with altitude. By contrast, IOD and interannual rainfall impacts on interannual disease cycles increased with altitude. Our analysis revealed a nondecaying synchrony of similar magnitude in both malaria and rainfall, as expected under a Moran effect, supporting a role for climatic variability on malaria epidemic frequency, which might reflect rainfall-mediated changes in mosquito abundance.Conclusions.Synchronous malaria epidemics call for the integration of knowledge on the forcing of malaria transmission by environmental variability to develop robust malaria control and elimination programs.
AB - Background. Patterns of concerted fluctuation in populations-synchrony-can reveal impacts of climatic variability on disease dynamics. We examined whether malaria transmission has been synchronous in an area with a common rainfall regime and sensitive to the Indian Ocean Dipole (IOD), a global climatic phenomenon affecting weather patterns in East Africa.Methods.We studied malaria synchrony in 5 15-year long (1984-1999) monthly time series that encompass an altitudinal gradient, approximately 1000 m to 2000 m, along Lake Victoria basin. We quantified the association patterns between rainfall and malaria time series at different altitudes and across the altitudinal gradient encompassed by the study locations.Results.We found a positive seasonal association of rainfall with malaria, which decreased with altitude. By contrast, IOD and interannual rainfall impacts on interannual disease cycles increased with altitude. Our analysis revealed a nondecaying synchrony of similar magnitude in both malaria and rainfall, as expected under a Moran effect, supporting a role for climatic variability on malaria epidemic frequency, which might reflect rainfall-mediated changes in mosquito abundance.Conclusions.Synchronous malaria epidemics call for the integration of knowledge on the forcing of malaria transmission by environmental variability to develop robust malaria control and elimination programs.
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U2 - 10.1093/infdis/jis289
DO - 10.1093/infdis/jis289
M3 - Article
C2 - 22492847
AN - SCOPUS:84861557239
SN - 0022-1899
VL - 205
SP - 1885
EP - 1891
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 12
ER -
