In the early 19th century, the scourge of Yellow Fever was prevalent in the southern United States. It had originally come over from Africa with the slave trade. They called it “Yellow Jack” and it was relentless. The death toll was huge as outbreaks happened in the south and people fled north. Trains full of people trying to escape sickness were met at stations by armed men and forced to move on. These were called “shotgun quarantines”.
No one knew how it spread. They burned bonfires to disrupt “miasmas” that they thought caused sickness. Patients were quarantined and doctors believed contact with sick people and anything contaminated with their fluids passed disease. On doctor from Cuba, Carlos Finlay, put forth the idea that it was spread by mosquitoes. His paper, “The Mosquito Hypothetically Considered as the Transmitting Agent of Yellow Fever”, published and presented in August 1881 was groundbreaking. However, he was roundly criticized as a “crank” and a “crazy old man.” He spent twenty years attempting to prove this theory.
In 1898, the Spanish American War broke out. Cuba was a hot bed of Yellow Fever, and that was exactly where the bulk of US troops were stationed. Preventing the spread of Yellow Jack now became a matter of national security. Dr. Walter Reed was sent to Havana with an elite team to study the causes of the disease. His partner, Dr. Jesse Lazear, had studied with Reed at John Hopkins University. Lazear brought Finlay’s theory to Reed and they decided to test it.
They took nine volunteers and exposed them to mosquitoes who had fed on Yellow Fever patients. Nothing happened. Perplexed, Reed traveled back to the US on official business while Lazear keep researching. Quite by accident they found the cause. Lazear had a mosquito bite a colleague, Dr. Carroll. The difference was the mosquito sat for twelve days after biting a yellow fever patient. That incubation period proved crucial as Carroll fell ill. Sadly, the mosquito also bit Dr. Lazear and he fell ill as well and later died.
Reed was devastated. He called Lazear a martyr, and vowed he would not die in vain. To prove mosquitoes were the disease vector, Reed set up Camp Lazear. One house contained every nasty imaginable from Yellow Fever patients – linens stained with vomit, diarrhea and blood. Apparently, the smell was so bad one man had to leave to vomit as soon as he entered. The temperature was kept warm to replicate the summer weather. The other house was clean except for standing water to promote mosquito breeding. They paid volunteers 100 in gold to live in the two houses. If someone got sick they got 100 more. The volunteers in the mosquito house contracted Yellow Fever and the nasty secretions house volunteers did not. Finlay joined Reed at Camp Lazear to see his life work vindicated.
Based on their findings, the team suggested mosquito control to the army for Cuba. Standing water was eliminated and mosquitoes were controlled. Even though there was a significant decline in Yellow Fever cases in Havana, the US wasn’t buying it. The same precautions were shared, but they were blown off until an epidemic New Orleans. Mosquito removing precautions were taken and although the epidemic was still deadly the number of cases was greatly reduced.
On construction of the Panama Canal, the same practices were put in place to eradicate mosquitoes to protect workers. By the end of 1906, the efforts of the “mosquito brigade” had ended the epidemic which had begun in 1905. These practices saved many lives until a vaccine was developed in the 1940s.