Who led the medical research that identified the role of mosquitoes in transmitting yellow fever?

Who led the medical research that identified the role of mosquitoes in transmitting yellow fever?

• A. Louis Pasteur
• B. Walter Reed
• C. Edward Jenner
• D. Alexander Fleming

Answer: (B)

Understanding how diseases spread often hinges on identifying a vector—an organism that carries a pathogen between people. For yellow fever, the decisive discovery was that mosquitoes transmit the virus, and Walter Reed led the team that established this in Cuba around 1900. The Yellow Fever Commission, with colleagues such as James Carroll and Aristides Agramonte, conducted controlled experiments showing that healthy volunteers who were bitten by infected mosquitoes developed yellow fever, while those protected from bites did not. They also demonstrated that reducing mosquito populations and avoiding bites halted transmission. This work confirmed the mosquito as the carrier and transformed public health, shifting efforts to vector control to prevent outbreaks. The other figures—Louis Pasteur, Edward Jenner, and Alexander Fleming—made major contributions in other areas of microbiology and medicine, but not in identifying how yellow fever is transmitted via mosquitoes.

Understanding how diseases spread often hinges on identifying a vector—an organism that carries a pathogen between people. For yellow fever, the decisive discovery was that mosquitoes transmit the virus, and Walter Reed led the team that established this in Cuba around 1900. The Yellow Fever Commission, with colleagues such as James Carroll and Aristides Agramonte, conducted controlled experiments showing that healthy volunteers who were bitten by infected mosquitoes developed yellow fever, while those protected from bites did not. They also demonstrated that reducing mosquito populations and avoiding bites halted transmission. This work confirmed the mosquito as the carrier and transformed public health, shifting efforts to vector control to prevent outbreaks. The other figures—Louis Pasteur, Edward Jenner, and Alexander Fleming—made major contributions in other areas of microbiology and medicine, but not in identifying how yellow fever is transmitted via mosquitoes.