Sunday, October 09, 2005

Scientists lack respect for avian flu virus?

While the Spanish flu virus extracted from Alaskan permafrost victims is reborn into a living deadly virus strain by scientists at the US Centers for Disease Control and Prevention (CDC) in August, the viruses security rating is only high enough to be dealt with at Biological Safety Level 3 (BLS-3).

Even though team Tumpey found that the reconstructed virus killed otherwise healthy mice in 3 to 5 days and when the scientists infected samples of human-lung cells with the virus, it replicated readily this does not constitute a serious enough threat to gain the respect of BLS-4.

Why is it that the news wires are choked with stories of the danger of bird flu yet scientists do not consider the threat gravely serious when tinkering with the virus?

The Biological safety levels...

BSL-1 Appropriate for well-characterized agents not known to consistently cause disease in healthy adults, and of minimal potential hazard to laboratory personnel and the environment. Given higher threat levels, BSL-1 is generally not being used, and BSL-2 has become the baseline level in new public health labs.

BSL-2 In both BSL-1 and BSL-2, work can take place in an open laboratory environment, but BSL-2 work needs to be supervised by a qualified scientist. Access to the lab space must be controlled, and caution is required when handling sharp items and infectious aerosols and splashes. BSL-2 work might involve bacteria, influenza viruses, and even HIV.

BSL-3 BSL-3 work must be conducted in specially designed closed laboratory environments using biological safety cabinets. Materials involved can cause potentially lethal diseases (such as anthrax, tuberculosis, and West Nile virus) if inhaled.

BSL-4 BSL-4 agents can cause life-threatening, untreatable disease if inhaled. In addition to observing BSL-3 precautions, workers must wear one-piece pressure suits ventilated by life-support systems. Materials handled in this environment include the Ebola virus.

References:
http://www.financialexpress-bd.com/index3.asp?cnd=10/6/2005&section_id=26&newsid=2931&spcl=no
http://www.sciencenews.org/articles/20051008/fob2.asp