Government researchers must have known they were violating ethical standards by deliberately infecting Guatemalan prison inmates and mental patients with syphilis for an experiment in the 1940's, according to a presidential commission.
The U.S.-funded research in Guatemala did not treat participants as human beings or even the same as those who participated in similar studies in the United States, the commission's investigators said on Monday.
The United States apologized last year for the experiment, which was meant to test the drug penicillin, after it was uncovered decades later by a college professor.
President Barack Obama's Commission for the Study of Bioethical Issues investigated the syphilis experiment and discussed its key findings in Washington on Monday. A final report is due in December.
"The people who were in the know, did want to keep it secret because if it would become more widely known, it would become the subject of public criticism," said commission chairwoman Amy Gutmann, president of the University of Pennsylvania.
The commission's conclusions have consequences for U.S. diplomacy and will impact the ethical discussion surrounding how new drugs are tested on patients, as manufacturers increasingly conduct clinical trials abroad.
Guatemala condemned it as a crime against humanity and said last year it would consider taking the case to an international court. It is conducting its own investigation. Victims of the study are suing the U.S. government.
The commission's investigators said the study of sexually transmitted diseases like syphilis was an important scientific goal at the time.
But they said they found no reasonable excuse for the way in which the Guatemala study was conducted, noting that researchers deceived its participants, never published results, kept poor notes and conducted experiments in illogical order.
"It was bad science. Regardless of the ethical issues ... from a purely scientific standpoint, I found this body of science bereft of any point," said commission member Dr. Nelson Michael of the Walter Reed Army Institute of Research.
Some 700 people were infected with syphilis in the Guatemala study. These included inmates exposed to infected prostitutes brought into prisons and male and female patients in a mental hospital. Some subjects had bacteria poured on scrapes made on their genitals, arms or faces.
The patients were given antibiotic penicillin to test its ability to cure or prevent syphilis. The infection can cause genital sores and rashes and, if left untreated, damage internal organs and cause paralysis, blindness or death.