"I think one lab that is working with it inappropriately is too many. Fifty-six working with it appropriately is not a problem," he said. The Beijing incident is reminiscent of a notorious smallpox release in Birmingham, England, in August 1978 -- 10 months after the last wild infection occurred in Somalia. Henry S. Bedson, head of the microbiology department at a medical school, was rushing to finish his experiments before the deadline to turn in or destroy his stocks of smallpox. The lab's containment had been judged unsatisfactory by WHO inspectors, but they did not have the power to close it. The smallpox virus apparently became aerosolized in Bedson's lab and traveled up one floor through air ducts to the school's photographic studio and darkroom. A 40-year-old photographer became infected and died, even though she had been vaccinated 12 years earlier. She transmitted the virus to her mother, who also became ill but survived. Her father did not become infected but had a fatal heart attack. Bedson, despondent, slashed his throat in his potting shed, leaving a note in which he said, "I am sorry to have misplaced the trust which so many of my friends have placed in me and my work." The leaders of the effort to eradicate polio, who hope to finish the task this year or next, have been working since 1999 to ensure that no such tragedy mars that historic achievement. They have asked nearly 200,000 labs around the world whether they hold polio virus. To date, 833 have said they do, either in pure form or in fecal samples, Christopher Wolff, a WHO scientist, said recently. About 50 have since destroyed their stocks, and many more expect to do so once the disease disappears. The biggest disease outbreak that may have arisen from a laboratory was the mini-pandemic of "Russian flu" in 1977 and 1978. Despite its name, that strain of influenza virus appeared in Tientsin, China, in May 1977. It spread around the world, causing mild infection that almost exclusively hit people younger than 20. Millions of people became ill, although overall flu mortality did not increase. What is curious is that this virus had a genetic fingerprint virtually identical to a strain that had last circulated in 1950. Flu viruses evolve at a fairly predictable rate "and it is extremely difficult to explain why the . . . strains . . . are so strikingly familiar," a team of scientists wrote in 1978. There are two possible explanations. The first is that the 1950 virus was somehow "genetically frozen" in nature -- possibly in ice or perhaps in some human or animal carrier that has never been discovered. The second is that it escaped from a laboratory in China. Many scientists think the second is the more probable. | 
