Yellow fever lids of water tanks can be sprayed with insecticides, but application inside houses is not recommended by the WHO. Insecticide-treated mosquito nets are effective, just as they are against the "Anopheles" mosquito that carries malaria. As for other flavivirus infections, no cure is known for yellow fever. Hospitalization is advisable and intensive care may be necessary because of rapid deterioration in some cases. Different methods for acute treatment of the disease have been shown not to be very successful; passive immunization after the emergence of symptoms is probably without effect. Ribavirin and other antiviral drugs, as well as treatment with
Yellow fever the Louisiana Purchase to the US in 1803. In 1804, Haiti proclaimed its independence as the second republic in the Western Hemisphere. The yellow fever epidemic of 1793 in Philadelphia, which was then the capital of the United States, resulted in the deaths of several thousand people, more than 9% of the population. The national government fled the city, including President George Washington. Additional yellow fever epidemics struck Philadelphia, Baltimore, and New York City in the 18th and 19th centuries, and traveled along steamboat routes from New Orleans. They caused some 100,000–150,000 deaths in total. In 1853, Cloutierville, Louisiana, had