This mosquito-borne virus is most active in North America during the warm summer and fall months. In 2015, over 1,900 cases of West Nile were reported, 65% of which resulted in neuro-invasive diseases like meningitis or encephalitis. Symptoms of West Nile usually show within a few days after transmission and include fever, headache, nausea, vomiting, and rash. There is no specific treatment or vaccine for West Nile, so people are encouraged to use normal mosquito repellent techniques to avoid bites. Get to a hospital immediately, if you or a loved one is showing severe symptoms.