Role Models in Science & Engineering Achievement: Carlos Juan Finlay

Carlos Juan Finlay -- Cuban physician

He was the first to theorize that the deadly yellow fever virus was transmitted through the bite of one species of mosquito, however it would take years before his theory would be deemed correct.

We know today that yellow fever -- which is most common in Latin America and tropical areas of Africa --  is a viral infection spread to humans by infected mosquitoes. Yellow fever (the name "yellow" refers to the jaundice that affects some patients) is thought to have originated in Africa and was likely brought to the Americas on ships during the slave trade, researchers believe.  But the cause of this disease was virtually  a mystery until Cuban physician Carlos Juan Finlay, through painstaking research, determined its exact origin, thereby saving countless lives worldwide, especially in South America, the Caribbean, Africa and the southern U.S.

Carlos was born Juan Carlos Finlay in Puerto Principe (now Camagüey), Cuba, in 1833. His father, Scottish physician Edward Finlay, an ophthalmologist (eye treatment specialist), had moved to Cuba two years earlier with his French wife, Eliza de Barrés. Shortly after arriving in Cuba, they formally changed their names to Isabel and Eduardo to show how much they loved their new country. In 1847, at the age of 13, Juan was sent to Europe to begin his primary studies. When he returned to Cuba, he legally changed his name to Carlos Juan Finlay, as a way to further embrace his Cuban identity. After earning his medical degree from Jefferson Medical College in Philadelphia, Pennsylvania in 1855, he returned to Cuba and opened a medical practice.  It was then, in between his practice, that he began investigating the yellow fever disease, which had caused thousands of deaths in Cuba, and would later in the region even severely cripple work on the construction of the Panama Canal.

Why He's Important:  Carlos was the first to scientifically prove that the mosquito species Aedes Aegypti ( commonly known today as the “yellow fever mosquito“) was the transmitter of yellow fever. In addition, he conceived ways to prevent the spread of yellow fever -- methods which have since evolved into effective procedures to monitor such venues as communities, neighborhoods, airports, ship ports and other places that might constitute a risk in spreading the disease. But Carlos' path to having his theory about the disease accepted by the international medical community was not an easy one. He spoke at medical conferences in Havana and Washington, D.C. as early as 1871, but his hypothesis regarding the cause of yellow fever was met with silence. In 1900, during the first U.S. occupation of Cuba, a U.S. medical commission led by the noted military physician Walter Reed went to Havana to study the disease. At first the U.S. scientists in the commission didn't pursue Dr. Finlay's "mosquito" theories since they suspected that it was environmental "filth" that spread the yellow fever virus. When all their experiments failed, they began to look over Carlos' 19 years of research. Eventually  this led them to conclude that Carlos had been right all along.

Other Achievements: Carlos, a humane man who often took on patients who could not afford medical care, later went on to become the chief health officer of Cuba from 1902 to 1909. Although it has been said by some that Dr. Walter Reed  received much of the credit for "beating" yellow fever, Reed, in an address delivered in Baltimore in April 1901, said: "…to Dr. Carlos J. Finlay must be given, however, full credit for the theory of the propagation of Yellow Fever by the mosquito."  In addition, Carlos was nominated more than once for the Nobel Prize for his contributions to determining the cause of yellow fever, but never received the award.  He was awarded the prestigious National Order of the Legion of Honour of France in 1908, and the UNESCO Carlos J. Finlay Prize for Microbiology is named in his honor. In addition, a prominent monument known as El Obelisco (The Obelisk) stands in his honor in the city of Havana, Cuba.

He died at the age of 82 in 1915 in Havana.

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