We periodically take side trips to geographical points so that places mentioned in novels set during the Age of Sail are presented in context (see our Geography category). We recently looked at syphilis and it’s treatment by calomel of mercury for the same reason.
We’ll now hit another disease which terrorized sailors and landsmen alike during the Age of Sail. Yellow fever, also known as yellow jack.
According to Jared Diamond in Guns, Germs, and Steel, yellow jack came to the Americas from Africa via the slave trade. For those interested in the genetics of yellow fever there it a fascinating article here.
By the 18th century it was a firmly established fact of life in the Caribbean and Central America. It is of particular interest here because one of the focuses of this site are the Alan Lewrie novels by Dewey Lambdin. Yellow jack features prominently in at least two (I say “at least” because I haven’t finished the series yet) novels in that series.
Typically three to six days elapse between infection and the first symptoms of the disease. These symptoms can be fairly benign and last one to three days: fever, headache, bloody nose, nausea, and a slow heartbeat. Many suffers of yellow jack have these symptoms and recover completely.
A smaller number of people, about 15% of all infected, will develop severe yellow jack. Here the initial symptoms are: high fever (up to 104 degrees), headache; dizziness; seizures; pain in the neck, back, and legs; nausea; vomiting; red eyes; and, a loody nose and/or gums.
After about three days these symptoms go into remission. During this second, or remission, stage, which lasts several hours to two days, the symptoms are: bleeding, confusion, and a complete stoppage of urine production
Most make a complete recovery after this stage. For a smaller number they pass to stage three. Here symptoms are: jaundice (yellowing of the skin and eyes); continued nose bleeds; blood in the stool; vaginal bleeding; vomiting blood; and problems in the liver, kidneys, lungs, or other organs — possibly leading to organ failure. Less than half of those reaching this stage recover. The majority fall into a coma lasting two to three days and die.
The actual mortality rate of yellow jack is hard to calculate because those who seek treatment or report the disease tend to be those with the severe variety of the disease and, like most diseases, it will strike hardest at the youngest, oldest, and those with a stressed or compromised immune system. A good estimate seems to be that 10% of those with severe yellow jack will die.
The first major outbreak of yellow jack in the New World was in Yucatan in 1648 and it rapidly spread throughout the region with the British army coming to regard assignment to the West Indies as tantamount to a death warrant. The French army sent to suppress Toussaint L’Ouverture’s rebellion was devastated by yellow jack, the mortality rate allegedly reaching 50%.
In an era before viral infections were understood and the idea of insect borne diseases not even conceived of, yellow jack was accompanied by terror. People who may have recovered were simply abandoned. Treatment by purgatives and bleedings, not to mention home remedies barely removed from witchcraft, undoubtedly killed some people who would have recovered.