Contact: Morgan Kelly
Caption: From 1995 to 2004, measles outbreaks in Niger (C, light-shaded area) spiked in the dry season. Satellite imagery of nighttime lights suggests that changes in population density contributed to the epidemics, rather than weather-related factors such as the rainy season (dark-shaded area). The researchers studied measles and nighttime-lights data from 2000 to 2004, the years in which the two datasets overlap. Measles cases in the three cities studied (D) followed the same pattern as the nighttime brightness (E) the researchers observed for each city, with transmission rates and brightness highest during the September to May dry season and lowest during the mid-year rainy season (shaded area on both datasets).
Credit: Image by Science/AAAS
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