West Nile Virus Activity 2005200620072008200920102011201220132014201520162017201820192020 Birds483019131010151897191122007Mosquitoes9921100001616201500 Horses2000000000000000Humans1101010201001000 2018 Alameda County WNV activity2017 Alameda County WNV activity2016 Alameda County WNV activity2015 Alameda County WNV activity2014 Alameda County WNV activityCalifornia West Nile virus activityNational West Nile virus activity