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
1793 Philadelphia yellow fever epidemic authorized. After an extensive debate in the newspapers, the State Assembly denied the petition. The recurrences of yellow fever kept discussions about causes, treatment and prevention going until the end of decade. Other major ports also had epidemics, beginning with Baltimore in 1794, New York in 1795 and 1798, and Wilmington in 1798, making yellow fever a national crisis. New York doctors finally admitted that they had had an outbreak of yellow fever in 1791 that killed more than 100 people. All the cities that suffered epidemics continued to grow rapidly. The widespread recognition that the epidemics were based along