What was the doctor’s name who was sent to Panama to fight Malaria when Panama Canal was being built?
I believe the person you are referring to is Dr. William Crawford Gorgas. Dr Gorgas was the chief sanitary officer for the Panama Canal project and had gained experience in controlling vector borne diseases while working in Havana, Cuba, where yellow fever was a problem.
It had also been shown a few years earlier, in 1898, that mosquitoes carried malaria as well. In Panama, Dr Gorgas focused his efforts on controlling mosquitoes, through drainage of standing water, adding larvicide and oil to remaining water and hand-collection of adult mosquitoes. In addition, Dr Gorgas screened all government buildings and workers’ quarters to prevent mosquitoes from entering, and gave workers prophylactic quinine. He was assisted in these endeavours by Dr Joseph Augustin LePrince and Dr Samuel Taylor Darling; together, their efforts led to the elimination of yellow fever from the canal zone and a great decrease in the number of malaria cases, though malaria continued to be a problem throughout the construction of the Panama Canal.