More reasons to dread rain on vacation? Dengue fever in 42 German and United Kingdom Madeira tourists during autumn 2012.

In October and November 2012 residents and tourists in the Autonomous Region of Madeira, Portugal, were affected by dengue fever. The outbreak waned during the unusually dry winter. Using a Monte Carlo test we investigated the hypothesis that rainy weather conveyed increased risk of dengue virus infection among tourists. Results confirmed the hypothesis. As it is unclear whether the outbreak is over, upkeep and emphasis on mosquito avoidance on rainy days may help residents and tourists reduce infection risk.