“It was a call to arms,” says Roberts. So he picked up the phone and contacted Butler, who painted a grim picture of the situation. Ever since the death sentence was handed down in 2004, the absurd case had been bouncing between Libya’s courts as the medics languished in jail; there had been at least one suicide attempt among them. Butler was glad Roberts wanted to help. After watching the Libyan affair from a journalist’s vantage point, says Butler, “I found myself in a position to be useful. What was needed was for someone to work behind the scenes, connecting influential scientists with each other and with diplomats involved with the case.”
Roberts began by calling on his fellow Nobel laureates to sign an open letter to Qaddafi. The letter described the case as a “miscarriage of justice” and called on the Libyan government to recognize the scientific evidence. Getting the laureates to do something in concert “is like herding cats,” he says, but Roberts managed to make contact with 125 of the 160. Within two weeks, he had 114 signatures—the most signatures ever obtained from science laureates for such a joint statement. It was published November 9, 2006, in Nature. “That had a big impact,” says Butler, “particularly on the politicians involved. It helped to ratchet up the pressure.”
Roberts was determined to present the letter to Qaddafi in person. But then he wondered, how does one make contact with a dictator?
While Roberts was stalking Qaddafi, Oliver Pybus was working in his office at the University of Oxford, blissfully unaware that he was about to become a central player in the Libyan affair. He was joined by Tulio de Oliveira and Andrew Rambaut, also viral-evolution researchers at Oxford, who sat down and proposed an analysis that had never been used in a court of law. The Oxford scientists are world experts in using genetic markers to reconstruct the evolution of viruses on the timescale of centuries as they jump between populations. “But we also knew that we could adapt these tools to address this case,” says Pybus. The problem was that there were only six weeks to go before the Libyan court was due to announce a decision on the medics’ final appeal to avoid the firing squad.
The researchers dropped everything and worked around the clock. “We disappeared,” says Pybus. While those viruses reproduced and spread from host to host, their genomes accumulated a pattern of mutations that told a story. The Oxford group aimed to reconstruct that story in reverse. Its ending was known—66 children entered a hospital on different dates and became infected with two kinds of viruses—but how did the story begin?
According to the prosecution, it began with a glass vial kept in the apartment of one of the Bulgarian nurses in Libya. She took the viral stock to the hospital and, with the help of her coconspirators, injected a dose into each of the infected children, starting in March 1998 and continuing up to the nurses’ arrest in February 1999. If true, then running all those viral molecular clocks backward should establish when the virus that infected the children first appeared. “We were worried that someone might criticize us for hand-picking our methods to get the answer we wanted,” says Pybus. “So we essentially threw the book at the data.” Instead of using one model with one set of assumptions and constraints, the researchers analyzed the data with every molecular clock model available. Pybus used his administrative privileges to devote his department’s supercomputer full-throttle to the Libyan data.
The analysis was finished on November 3, 2006, and the conclusion was brilliantly clear. The arrival of the virus at the hospital predated the arrival of the medical workers in Libya. The molecular clock resoundingly exonerated the medics. Every model the Oxford group tested put the age of the viral outbreak before March 1998, many as early as 1995. In fact, the pattern looked like that of a protracted hospital outbreak in which patients had been infecting each other over many years, with viruses becoming isolated, building up very different signatures of mutations, and reinfecting patients via surgical equipment or blood supplies.
If the foreign medical workers didn’t start the HIV outbreak, who did? Colizzi and others had argued all along that the most likely explanation is that someone—perhaps one of Libya’s many HIV-infected West African refugees, possibly a pregnant mother—checked into the Benghazi hospital in the mid-1990s. Through one of several unhygienic practices there, the HIV in her blood joined a circulating pool of viruses among the hospital’s recurrent patients. DNA sequencing of the children’s HIV had already identified it as sub-Saharan. The hepatitis in the children’s blood matched a strain from Egypt. “Multiple outbreaks had already been going strong at Benghazi for a decade,” says Colizzi.
The trio wrote up their results in three days and submitted them to Nature. The paper went through peer review and was published two weeks ahead of the Libyan court date. “The usual standard of justice is to prove that someone is guilty beyond a reasonable doubt,” said Jeffrey Thorne, a statistical geneticist at North Carolina State University in Raleigh, after reading the paper. “But this shows that the accused medical staff were innocent beyond a reasonable doubt.”
Scientists weren’t the only ones to take notice. “Until then, I was getting the same infuriating question from many of the politicians I spoke with,” says Butler. “‘How do you know the medics didn’t do it?’” But once the molecular study was out there, “the atmosphere changed. I never heard that question again.”
That made it all the more appalling on December 19, when the Libyan court, making no reference at all to the Nature study proving the medics’ innocence, rejected their final appeal and confirmed the death sentences.
The Libyan regime had made it clear that they were either unable to understand scientific evidence or gave it no value. Colizzi and his colleagues redoubled their efforts to reach out to the Libyans, promising a lifetime of world-class treatment for the infected children if the medics were set free. In spite of the increasingly tense atmosphere, Colizzi and Massimo Amicosante, another HIV researcher at Tor Vergata University, continued to visit Libya. “I have to watch my back these days,” Colizzi told me then. He was only half joking.
But no one worked harder than Roberts. He was not worried that the medics would be executed: They were far too valuable to the Libyans. His worst-case scenario was that the death sentences would be commuted in exchange for blood money and the medics would spend the rest of their lives in a Libyan jail.