The most severe kind of the disease is called dengue hemorrhagic fever. People who have this
disease bleed from the nose or other openings in the body. Dengue hemorrhagic fever kills about five
percent of all people it infects. The only treatment involves controlling the bleeding and replacing lost
body fluids.
Yellow fever is another disease carried by mosquitoes. There are no effective drugs against yellow
fever. Doctors can only hope that a person's defense system is strong enough to fight the disease.
Yellow fever is found mainly in Africa, the northern part of South America and the islands of the
Caribbean Sea. The World Health Organization says there are an estimated two hundred thousand
cases of the disease and thirty thousand deaths each year