Yellow fever as well as larvae-eating fish and copepods, which reduce the number of larvae. For many years, copepods of the genus "Mesocyclops" have been used in Vietnam for preventing dengue fever. It eradicated the mosquito vector in several areas. Similar efforts may be effective against yellow fever. Pyriproxyfen is recommended as a chemical larvicide, mainly because it is safe for humans and effective even in small doses. The second strategy is to reduce populations of the adult yellow fever mosquito. Lethal ovitraps can reduce "Aedes" populations, but with a decreased amount of pesticide because it targets the mosquitoes directly. Curtains and
Yellow fever cycle has yet been established, scientists believe this could happen again at any point. An outbreak in Paraguay in 2008 was thought to be urban in nature, but this ultimately proved not to be the case. In Africa, virus eradication programs have mostly relied upon vaccination. These programs have largely been unsuccessful because they were unable to break the sylvatic cycle involving wild primates. With few countries establishing regular vaccination programs, measures to fight yellow fever have been neglected, making the future spread of the virus more likely. In the hamster model of yellow fever, early administration of the antiviral