A vial of smallpox vaccine. The virus was declared eradicated in 1980. Photo: Getty Images
Washington: A US government scientist cleaning out a storage room at a laboratory of the National Institutes of Health in Bethesda, Maryland, has found decades-old vials of smallpox, the second incident involving the mishandling of a highly dangerous pathogen by a US health agency in a month.
This is the first time that the deadly virus has been discovered outside the only two facilities in the world where smallpox samples are allowed, by international agreement, to be stored - a highly secure lab in Atlanta, US, and a virology and biotechnology research centre in Novosibirsk, Russia. It remains a mystery how the smallpox came to be stored at the laboratory.
The vials, which appear to date from the 1950s, were flown on Sunday night by government plane to the Centres for Disease Control and Prevention headquarters in Atlanta, Georgia, officials said on Tuesday. Initial testing confirmed the presence of smallpox virus DNA. Further testing, which could take up to two weeks, will determine whether the material is live. The samples will be destroyed after the testing is completed.
A micrograph of the smallpox virus. Photo: US Centres for Disease Control
There is no evidence that any of the vials had been breached or that workers in the lab, which has been used by the Food and Drug Administration for decades, were exposed to infection. The Federal Bureau of Investigation and the CDC's division of select agents and toxins are investigating.
Smallpox was eradicated globally by 1980. But the disease killed hundreds of millions of people in the 20th century alone. The last Australian case of smallpox was in 1938 and in the US, 1949. The last naturally occurring case anywhere in the world was in Somalia in 1977, according to the CDC. Since then, according to the World Health Organisation, the only known cases stemmed from a 1978 lab accident in England.
There is no cure for smallpox, and historically about one-third of people who contract it die from the disease.
Last month, a safety lapse involving three CDC labs in Atlanta led to the accidental release of live anthrax bacteria, an incident that required as many as 84 employees to get a vaccine or take antibiotics as a precaution and resulted in the reassignment of one lab director.
The Washington Post, Los Angeles Times