WASHINGTON, Aug. 29 (UPI) -- Federal investigators said they determined Monday U.S. researchers conducted sexual disease experiments on unwitting Guatemalans in the 1940s.
The Presidential Commission for the Study of Bioethical Issues reported U.S. government researchers knew they were acting unethically when they intentionally infected people with sexually transmitted diseases without the subjects' knowledge because just a few years earlier they had obtained consent before similar experiments in Indiana, The Washington Post reported.
"These researchers knew these were unethical experiments and they conducted them anyway," said commission Member Raju Kucherlapati of Harvard Medical School. "That is what is reprehensible."
The various experiments conducted decades ago involved at least 5,500 prisoners, mental patients, soldiers and children, the Post said. At least 1,300 of them were exposed to syphilis, gonorrhea and chancroid, the commission said.
At least 83 subjects died, though it could not determine how many deaths were a direct result of the experiments, the commission said.
"This is a dark chapter in our history," commission Chairwoman Amy Gutmann of the University of Pennsylvania said. "It is important to shine the light of day on it. We owe it to the people of Guatemala who were experimented on, and we owe it to ourselves to recognize what a dark chapter it was."
President Barack Obama ordered the investigation after the experiments, which had approval from some Guatemalan officials, came to light last October. Guatemala is conducting its own investigation.
The research, conducted between 1946 and 1948, had been aimed at determining whether taking penicillin after sex would protect against syphilis, gonorrhea and chancroid.
The Post said researchers infected subjects by bringing them to infected prostitutes, placing STD bacteria on the wounds they made on their penises, faces and arms, or injecting infectious material into their spines.