Does "Yellow Fever" evoke images of pirate ships, explorers in pith helmets, or flickering documentaries from the last century? You may be gloating that "Yellow Jack" is a disease that's safely buried in the history books.

Cold comfort to the 30,000 people who are likely to die this year of a virus that is now classified as a "re-emerging" disease, and has been cited as a potential bioweapon. Related to the deadly Ebola virus, This "hemorrhagic fever" originated in the jungles of Africa, and then moved with the slave trade to South America where it proved devastating to Europeans. It wiped out 27,000 troops during Napoleon's attempt to invade Haiti in 1803, and was responsible for over 90% of the deaths in the Spanish American war in 1899. However, the mode of transmission remained baffling. A Cuban physician named Carlos Finlay postulated that it might be carried by mosquitoes, but the idea was ridiculed. To disprove the theory, in 1900 Dr. Jesse Lazear inoculated himself with an infected mosquito and died of Yellow Fever a week later. This prompted more careful experiments by army surgeon Walter Reed. Volunteers moved into rooms furnished with beds with sheets caked with "black vomit" and clothing taken from persons dead of Yellow Fever. The volunteers remained healthy. In a second experiment, 10 volunteers were paid $200 each to be bitten by infected mosquitoes. Three died immediately from Yellow Fever. This proved conclusively that you should never volunteer for experiments. (Reed himself died two years later -- from a ruptured appendix.)

Aggressive mosquito control by Dr. William Gorgas enabled successful construction of the Panama Canal, and after the 1940's vaccines allowed westerners to travel with impunity to South America and Africa, where the chances of getting Yellow Fever can run about one in 20,000 after a two-week stay. If you are dumb enough to skip vaccination and get bitten by an infected Aedes aegypti mosquito, you might think you have the flue, with fever, back pain and headache. But in one of seven cases, the symptoms become more dramatic -- "black vomit" from intestinal hemorrhage and liver failure that causes jaundice (putting the "Yellow" in "Yellow Fever") and a 50% chance that you'll soon be pushing up daises in the family cemetery. As with all the single-strand RNA flaviviruses, there is no treatment or cure.

Just before you lapse into an excephalopathic coma, remember to mention that you climbed Kilimanjaro last week, otherwise no doctor will figure out what killed you. In the last 40 years only nine cases have been reported in the United States.

Eight died.