Louise Pearce (March 5, 1885 – August 10, 1959) was an American pathologist at the Rockefeller Institute who helped develop a treatment for African sleeping sickness (trypanosomiasis). Sleeping sickness was a fatal epidemic which had devastated areas of Africa, killing two-thirds of the population of the Uganda protectorate between 1900 and 1906 alone. With chemists Walter Abraham Jacobs and Michael Heidelberger and pathologist , Pearce worked to develop and test arsenic-based drugs for its treatment. In 1920, Louise Pearce traveled to the Belgian Congo where she designed and carried out a drug testing protocol for human trials to establish 's safety, effectiveness, and optimum dosage. Tryparsamide proved successful in combating the fatal epidemic, curing 80% of cases.