During his research at Camp Colombia, he confirmed the 1881 hypothesis of Carlos Finlay that mosquitoes transmitted this disease. Lazear was the only member of the commission who had experience working with mosquitoes, and he used mosquito larvae from Finlay's laboratory. He wrote to his wife in a letter dated September 8, 1900, "I rather think I am on the track of the real germ."[8] Lazear deliberately allowed an infected mosquito to bite him in order to study the disease.