Mosquito
Mosquito-borne diseases are currently most prevalent in East Africa, Latin America,  Southeast Asia, and India; however, emergence of vector-borne diseases in Europe have recently been observed. A weighted risk analysis demonstrated associations to climate for 49% of infectious diseases in Europe including all transmission routes. One statistical model predicts by 2030, the climate of southern Great Britain will be climatically-suitable for malaria transmission "Plasmodium vivax" malaria for 2 months of the year. By 2080 it is predicted that the same will be true for southern Scotland.
Jean Charles Faget
His medical practice began during an era when yellow fever was a tremendous problem in New Orleans. The exact cause of yellow fever was not known at the time. Early scientists believed that it was caused by environmental problems like rotting food, weather conditions, and poor sanitation. Faget's observations of the disease prompted him to believe that the disease could be attributed to a specific microorganism. It is now known that yellow fever is a virus that is transmitted by the bite of female mosquitoes (the yellow fever mosquito, "Aedes aegypti", and other species) and is found in tropical and subtropical areas in South America and Africa. The origin of the disease is most likely to be Africa, from where it was introduced to South America through the slave trade in the 16th century. During Faget's lifetime, yellow fever was deemed one of the most dangerous infectious diseases.