Monday, April 16, 2012

Where should flu work happen?

With the H5 controversy of the last few months, there has been some talk about moving the mammalian transmissible or even all highly pathogenic flu viruses into BSL4 laboratories.  Here is why it’s a terrible idea.

BSL3, BSL3+, BSL4: What’s the difference?


BL3 personal protection
BSL3 is a lab that has certain safety and containment features that go above and beyond a typical molecular biology or chemistry lab (typically BSL2).  BSL3 labs are required to be behind double locked doors. The lab space is required to be maintained under a negative air pressure so that opening doors or unintentional breach of containment causes air to be pulled into the lab as opposed to it  (and what ever is in it) being blown out of the lab.  Additionally, all waste generated is required to be recovered and decontaminated prior to disposal.  Finally, all personnel working in a BSL3 lab are required to wear additional personal protective equipment (PPE). This includes disposable lab coats, multiple disposable shoe covers and multiple gloves, as well as surgical style facemask.
Bl3+ personal protection
BSL3+, other wise known as BSL3 agriculture or BSL3 enhanced, has significant upgrades to the security and safety measures of BSL3.  A BSL3+ is required to have a pass through autoclave so that all solid waste is decontaminated prior to leaving the facility. The researchers body is the only thing that leaves BSL3+ without going through the autoclave (with very few exceptions and only with proper permission and safety protocols).  The scrubs they wear under their PPE are removed in the facility and the researchers are required to shower out in order to leave. PPE is similar to BSL3 but also include a Tyvek coverall and a loose fitting overhead PAPR (powered air purifying respirator) that is equipped with a HEPA filter to scrub the air they breathe. The facility is sealed airtight and all rooms are monitored for pressure changes multiple times a day and the air itself is double HEPA filtered. The entire facility can be decontaminated via gas decon ports from the outside. All security features have built in redundancies and back ups.  Prior to gaining access to a BSL3+ lab, a worker must undergo extensive training and testing and must pass an FBI background check.
A BSL4 lab is the highest level of biosafety and containment possible.  It includes all the elements of a BSL3+ lab with two main differences. Researchers are required to wear a fully sealed suit that air is pumped into from either the outside or a sealed air tank.  These are the moon suits you see in movies like ‘Contagion’ or ‘Outbreak’.  Additionally, the researchers take a chemical decontamination shower to exit the lab. 
BL4 personal protection

Where should it be? 


Currently all work done in the US or with US grant money utilizing highly pathogenic influenza is performed under BSL3+ conditions.  All facilities are inspected annually by relevant agencies depending on the pathogens in use. This can include the CDC, NIH, USDA and others. Are these safety features enough for these viruses? BSL3 and BSL4 are reserved for work with pathogens that can cause severe to fatal infections in humans.  The difference between BSL3 and BSL4 is that BSL3 agents have known and effective treatment strategies and BSL4 agents do not.  The only exception being smallpox in BSL4 due to the fact that it has been eliminated from nature.  With this in mind, where should mammalian transmissible H5N1 or all highly pathogenic influenza strains be?  There is no doubt that highly pathogenic influenza is a very deadly pathogen. The ability to become airborne means standard BSL3 conditions are probably not adequate protection.  However the use of PAPRs in BSL3+ are capable of filtering virus out of the air.  The research done with these viruses is very clear.  The drugs and vaccines we currently have are still very effective against these strains making BSL4 inappropriate.  Finally, highly pathogenic influenza is found readily in nature. Humans are exposed to it daily.  All of this leads to one very clear conclusion:  Highly pathogenic avian influenza, mammalian transmissible or not, does not belong in BSL4.  BSL3+ is sufficient protection.  A move to BSL4 would be unnecessarily disastrous, not only to influenza research, but also all current BSL4 pathogens.  A move to BSL4 would kill many flu labs do to a lack of appropriate facilities. Those flu researchers who would still have access to BSL4 facilities would then be jockeying for time and space inside the facilities that already house other research groups.  Retarding research on understanding the most dangerous pathogens is an indescribably terrible idea.  
Even Charles Barkley knows the move is a bad idea.

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