A genetic analysis of the AIDS virus in Libyan children appears to exonerate a Palestinian physician and five Bulgarian nurses accused of deliberately injecting 426 children with HIV at a Benghazi hospital in 1998, researchers reported today.
The genetic history of the human immunodeficiency virus indicates that it is a common West African strain that was circulating in Libya long before the group's arrival, a British and Italian team reported in the journal Nature.
The findings contradict the Libyan government's claims that the children were infected with an exotic, perhaps man-made, form of the virus and that the country was the only African nation with no cases of the deadly disease before the healthcare workers arrived in March 1998.
A verdict in the workers' second trial is expected Dec. 19, and scientists hope the analysis results will lead to an acquittal.
The so-called Benghazi Six -- Palestinian Dr. Ashraf Alhajouj and Bulgarian nurses Snezhana Dimitrova, Nasya Nenova, Valentina Siropulo, Valia Cherveniashka and Kristiana Valcheva -- have been imprisoned in Libya since 1999.
"The data are pretty clear that the infection in the hospital was obviously there before the Bulgarian health workers arrived," said viral geneticist David M. Hillis of the University of Texas at Austin, who was not involved in the research. "It is clear proof that the Bulgarian healthcare workers did not infect the children in the hospital."
Thomas Leitner, who maintains an HIV sequence database at Los Alamos National Laboratory in New Mexico and who also was not involved in the research, said, "I find their analysis well done and timely, hopefully affecting the judgment in the Libyan court."
But Libyan courts already have rejected scientific evidence suggesting that the infections were the result of poor hospital hygiene, and it is not clear how the new data will be received.
There have been suggestions that Libya would free the workers if their governments paid about $5.5 billion in "blood money" to the families of the children -- more than double the amount Libya has paid to the families of passengers on Pan Am Flight 103, which crashed in Lockerbie, Scotland, in 1988 after a bombing carried out by Libyan intelligence officers.
"It is critical to recognize that the unfortunate Benghazi Six ... are pawns in a far larger game," said Laurie Garrett of the Council on Foreign Relations in New York.
The six were part of a larger group of volunteers who came to Al Fateh Hospital in Benghazi in 1998 to help care for patients.
During the course of that year, 426 children at the hospital were diagnosed with acquired immune deficiency syndrome. At least 50 have died. The majority of those who survived were sent to Europe for treatment that was not available in Libya.
The following year, 19 of the foreigners were arrested, and 13 were subsequently released.
The six remaining detainees confessed to deliberately infecting the children, but they and Amnesty International later said the confessions were obtained by torture, including beatings with barbed wire, electroshock, dog attacks and other abuses.
Dr. Luc Montagnier of the Pasteur Institute in Paris and Dr. Vittorio Colizzi of the University of Rome Tor Vergata presented evidence at the first trial, including a preliminary analysis of the virus, indicating that the infections had begun long before the foreign workers arrived.
The fact that most of the children were also infected with hepatitis B and C indicated that the infections resulted from poor hospital hygiene, particularly improper needle sterilization.
But the court threw out their findings because an investigation by Libyan doctors had reached the opposite conclusion.
The six healthcare workers were convicted and sentenced to death in 2004. Nine Libyan officers accused of torturing them were acquitted in 2005.
In the face of international outrage, the Libyan Supreme Court quashed the conviction and sent the case back to a lower court for retrial.
The Libyan prosecutor in the new trial again called for the death penalty.
A group of more than 100 Nobel laureates wrote a letter published in Nature in October urging that the workers be freed. Another group of researchers published a similar letter, written by HIV co-discoverer Dr. Robert Gallo, in the journal Science, and scientific organizations have added to the pressure.
With the new verdict looming, Dr. Oliver Pybus and Dr. Tulio de Oliveira of Oxford University worked round-the-clock to analyze viral DNA collected from the children by European doctors.
Along with Colizzi and other co-workers, they reported in Nature that both the HIV and hepatitis viruses isolated from the children were common West African strains that had been circulating in the hospital since at least the mid-1990s.
"We put a 'timescale' on the transmission history of the transmission clusters, which enables us to show that the strains involved were already present and transmitting in the hospital and its environs prior to the arrival of the nurses," Colizzi said in an e-mail.
Neither Pybus nor Colizzi was willing to speculate about how much credence the Libyan court would give the new evidence.
"But now the political action of Western countries is more scientifically based and hence more effective," he said.