Carlos J. Finlay, baptized as Juan Carlos, was born in Puerto Príncipe (present city of Camagüey, Cuba) on December 3, 1833.
His given name was Juan Carlos, but he signed his name “Carlos J.”. His father was Dr. Edward Finlay Wilson, a British doctor born in the city of Hull, in the county of Yorkshire, and his mother, Marie de Barrés de Molard Tardy de Montravel, of French origin, born on the island of Trinidad and Tobago.
His childhood was spent both in Havana and in his father’s coffee plantation in the Alquízar area. At the age of eleven in 1844, he was sent to study in Le Havre, France. Two years later he returned to Cuba due to illness. He would return to France in 1848, to complete his education. After a period in London, he entered the Lycée de Rouen (France), where he remained until 1851, when he returned to Cuba, convalescing from an attack of typhoid fever.
When he was unable to enter the University of Havana, he went to Philadelphia (United States) where he studied medicine at Jefferson Medical College, where he obtained his doctorate on March 10, 1855. In 1857 he revalidated his degree at the University of Havana. Between 1859 and 1861 he studied in France
On February 18, 1881, at an international sanitary conference held in the capital of the United States (which he attended as a member of the Spanish delegation, representing Cuba and Puerto Rico), he explained that, since the mode of propagation of yellow fever did not conform to the schemes of contagionism and anticontagionism, it was necessary to postulate “an agent whose existence is completely independent of the disease and the sick person”, capable of transmitting the germ of the disease from the sick individual to the healthy one. This was, in essence, the theory of the mode of transmission of yellow fever put forward by Finlay.
On August 14, 1881, he presented before the Royal Academy of Havana his work The Mosquito Hypothetically Considered as the Agent of Transmission of Yellow Fever. Thanks to a series of precise deductions, based on the habits of the different species of mosquitoes existing in Havana, Finlay correctly indicated -in the aforementioned memoir- that the transmitting agent of yellow fever was the female of the mosquito species known today as Aedes aegypti. This work was published in the same year in the Annals of the aforementioned Academy.
The role of this mosquito was convincingly demonstrated, not by Reed’s experiments, but by the virtual elimination of yellow fever in Havana in 1901, as a result of a campaign led by the U.S. military doctor William Gorgas.
The measures applied were based on the recommendations previously formulated by Finlay, so their success was, in the end, the most tangible demonstration that their author had been right. This was recognized by Gorgas himself in a letter he addressed to Finlay years later, from Panama, where he also put into practice the measures proposed by the Cuban doctor, which made it possible to complete the Panama Canal, a plaque in the Canal itself recognizes the contribution of Dr. Carlos J. Finlay in the success of this great work.
In 1902, when Cuba’s independence was proclaimed, Carlos J. Finlay was appointed Superior Chief of Health, and structured the country’s health system on a new basis. From this position, he had to face the last epidemic of yellow fever in Havana in 1905, which was eliminated in three months.
Carlos J. Finlay died on August 19, 1915 in Havana at the age of 81.