Researchers from Boston University have discovered that mosquitoes carry even more viruses than previously thought, including yellow fever, dengue, and other highly advanced forms of the disease. The discovery was made after examining the immune system of Aedes aegypti, a common mosquito found on all continents. The researchers believe the discovery could be used as tools to treat non-infected mosquitoes and potentially develop their immune systems to combat human diseases. The European Centre for Disease Prevention and Control has warned of a resurgence of mosquito-borne diseases in southern Europe.