Dengue fever cannot spread directly from person to person. However, a person suffering from dengue fever can infect mosquitoes. In particular, the Aedes mosquito is known to spread dengue fever. The mosquito becomes infected when it takes a blood meal from a dengue-infected person. It then spreads dengue fever to other people they bite. There are 4 strains of dengue viruses. If you are infected by one type and develop immunity, it is still possible to become infected by the other 3 strains during your lifetime.