U.S. government medical researchers intentionally infected hundreds of people in Guatemala, including institutionalized mental patients, with gonorrhea and syphilis without their knowledge or permission more than 60 years ago.

Many of those infected were encouraged to pass the infection onto others as part of the study.

About one third of those who were infected never got adequate treatment.

On Friday, Secretary of State Hillary Clinton and Health and Human Services Secretary Kathleen Sebelius offered extensive apologies for actions taken by the U.S. Public Health Service.

"The sexually transmitted disease inoculation study conducted from 1946-1948 in Guatemala was clearly unethical," according to the joint statement from Clinton and Sebelius. "Although these events occurred more than 64 years ago, we are outraged that such reprehensible research could have occurred under the guise of public health. We deeply regret that it happened, and we apologize to all the individuals who were affected by such abhorrent research practices."

Secretary Clinton called Guatemalan president Alvara Cabellaros Thursday night to reaffirm the importance of the U.S. relationship with the Latin American country. President Barack Obama called Cabellaros Friday afternoon, according to a statement from White House press secretary Robert Gibbs.

"The people of Guatemala are our close friends and neighbors in the Americas," the government statement says. "As we move forward to better understand this appalling event, we reaffirm the importance of our relationship with Guatemala, and our respect for the Guatemalan people, as well as our commitment to the highest standards of ethics in medical research."

During a conference call Friday with National Institutes of Health Director Francis Collins and Assistant Secretary of State Arturo Valenzuela, officials noted that there were no formalized regulations regarding protection of human studies during the 1940s.

In addition to the apology, the U.S. is setting up commissions to ensure that human medical research conducted around the globe meets "rigorous ethical standards." U.S. officials are also launching investigations to uncover exactly what happened during the experiments.

The episode raises inevitable comparisons to the infamous Tuskegee experiment, the Alabama study where hundreds of African-American men were told they were being treated for syphilis, but in fact were denied treatment. That U.S. government study lasted from 1932 until press reports revealed it in 1972.

The Guatemala experiments, which were conducted between 1946 and 1948, never provided any useful information and the records were hidden.

Susan Reverby, a professor of women's studies at Wellesley College in Massachusetts, discovered records documenting U.S. experiments that infected Guatemalans with gonorrhea and syphilis.

They were discovered by Susan Reverby, a professor of women's studies at Wellesley College in Massachusetts and were posted on her website.

According to Reverby’s report, the Guatemalan project was co-sponsored by the U.S. Public Health Service, the NIH, the Pan-American Health Sanitary Bureau (now the Pan American Health Organization) and the Guatemalan government. The experiments involved 696 subjects — male prisoners and female patients in the National Mental Health Hospital.

The researchers were trying to determine whether the antibiotic penicillin could prevent syphilis infection, not just cure it, Reverby writes. After the subjects were infected with the syphilis bacteria — through visits with prostitutes who had the disease and direct inoculations — it is unclear whether they were later cured or given proper medical care, Reverby notes. While most of the patients got treatment, experts estimate as many as a one-third, did not.

Secret testing of Guatemalans may renew minorities mistrust

The STD experiments were conducted with the cooperation of the Guatemalan government. During that time, the U.S. -- which had a long association with the Guatemalan military -- exerted a powerful influence in the Latin American country, largely in order to protect the interests of the American-based United Fruit Company. In 1954 the U.S. CIA helped overthrow Guatemala’s democratically elected president because of land reforms that opposed the multinational corporation.

U.S. apologizes for health experiments (on this page)

Reverby, who has written extensively about the Tuskegee experiments, found the evidence while conducting further research on the Alabama syphilis study.

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