during his time at lukunga, boone saw and treated patients from all over the congo suffering from a variety of tropical diseases, in addition to eurasian infectious diseases such as smallpox and measles likely introduced by europeans and americans. he treated "malaria fever, persistent malaria, hemorrhagic fever, smallpox, leprosy, measles, tonsillitis, meningitis, pleuritis, pericarditis, consumption [tuberculosis], pneumonia, sleeping sickness, cancer and ulcers." his first surgery was an amputation he performed on a man whose broken leg had developed an ulcer to the bone. boone wrote that his success with the amputation, along with another, inspired him to return to the united states to study medicine.