Guatemala STD tests 'may have infected 2,500' Published duration 1 September 2011

image caption Hundreds of people were infected with syphilis bacteria during the experiments

The extent of US medical experiments in Guatemala on STDs during the 1940s is greater than previously thought, health authorities have told the BBC.

The number of infected people could be as high as 2,500, says the president of the Medical Association of Guatemala.

According to a US report released on Monday, 1,300 Guatemalans were infected without their knowledge to study the effects of penicillin.

US scientists knew they were violating ethical rules, the report found.

There is also enough evidence to conclude there was collaboration between US and Guatemalan authorities at the time of the tests, Carlos Mejia, a member of the commission established by the Guatemalan government to investigate the experiments, told BBC Mundo's Ignacio de Los Reyes.

At least nine Guatemalan doctors were involved in these experiments, he said.

Eight of them have already died, but authorities still do not know the whereabouts of a ninth, who would now be over 90 years old, he added.

The commission's final report is due in October.

Many of the same US government scientists who carried out the Guatemalan tests had sought consent from participants in an earlier study in the US.

'Nazi-like'

The US Presidential Commission for the Study of Bioethical Issues had said some 5,500 Guatemalans were involved in all the research that took place between 1946 and 1948, with a view to applying the results on US troops stationed around the world.

Of these, some 1,300 prisoners, psychiatric patients and sex workers were deliberately infected with syphilis, gonorrhoea or another sexually transmitted disease, chancroid.

Concentrations of bacteria were injected into the eyes, the central nervous system and male genitals. Mr Mejia says this was behaviour very similar to that of the scientists in Nazi Germany.

"It took place in the context in which they [the United States] were judging the German doctors who had been experimenting with typhus and malaria on prisoners of war. The Nazis used Poles, Russians and Jews, while the Americans made almost the same use of Guatemalans," he says.

Of the group of 1,300, only about 700 received some sort of treatment.

According to documents the commission had studied, at least 83 of the 5,500 subjects had died by the end of 1953.

The commission was unable to say whether any of those deaths were caused directly or indirectly by the deliberate infections.

US President Barack Obama set up the commission when academic research carried out on the experiments by US government scientists first came to light last year.

He also apologised to his Guatemalan counterpart, Alvaro Colom, saying the acts ran contrary to American values.