Despite the first days of spring, winter’s not over yet.
The United States celebrates National Doctor’s Day this week. The holiday received a proclamation in 1991 by President George Bush, who urged all Americans to recognize how “physicians have enabled mankind to make significant strides in the ongoing struggle against disease.” The commemorative day takes place on March 30 in the U.S. and is similar to other Doctor’s Days celebrated around the globe.
This holiday is recognized in many other countries but isn’t always celebrated on the same day. In Cuba, the holiday carries special significance but is celebrated on December 3. The country chose this day to mark the birthday of Dr. Carlos Juan Finlay (1833-1915). His contributions to medicine have impacted medicine and saved countless lives throughout the world.
Finlay was a Cuban physician who made a groundbreaking discovery in the fight against yellow fever. In 1881, he was the very first scientist to connect the disease to mosquitoes. Finlay theorized that the mosquito acted as a disease vector, which meant the insect could spread yellow fever by biting a victim and then biting and infecting a healthy person. This seemed like an outlandish notion back in the day, but Finlay was spot on in his observations. Thanks to Finlay’s recommendations, the spread of mosquito-borne diseases has been significantly reduced through population control of the bugs.
For over 20 years, Finlay stood firm in his discovery as fellow scientists and publishers rejected the notion of disease-spreading mosquitoes. His discovery became the subject of vigorous debate throughout the medical community. Yellow fever had already ravaged Cuba for centuries. Finlay had previously studied the spread of the cholera bacterium, which is generally spread through water contamination. His new theory about yellow fever and mosquitoes “challenged the received wisdom of medical authorities” who had studied the disease without success.
Finlay wasn’t surprised that his yellow fever theory was seen as preposterous. His conclusion that cholera was a waterborne disease were initially met with skepticism too. So he wasn’t deterred when his first paper on yellow fever (1872) was waved away as nonsense. His paper received publication, but The Annals of the Academy of Medical, Physical, and Natural Sciences of Havana did not support Finlay’s hypothesis. Finlay’s conclusion — “I understand but too well that nothing less than an absolutely incontrovertible demonstration will be required before the generality of my colleagues accept a theory so entirely at variance with the ideas which have until now prevailed about yellow-fever” — assured the community that he’d do his best to prove his theory.
For 20 years, Finlay carried out a series of over 100 experiments on human volunteers. He wished to prove his theory’s truth and also explore immunity to yellow fever. Although his experiments were widely criticized by the medical community, Finlay eventually prevailed. He went on to serve as Chief Sanitary Officer of Cuba until his retirement in 1909. Finlay’s accomplishments and discovery of mosquitoes as disease vectors carry lasting effects to this day.