THE THIN WHITE LINE: the history of a future avian influenza pandemic

Chapter 2: State of Emergency

Genetic characterization

    Biosafety-Level 4. Five days earlier.
    Stepping carefully so that they remained constantly in view of each other, Wei moved to join Ambrose in setting up the isolation procedure for the virus samples they’d received. She tried not to think about what would happen if her air flow suddenly stopped, leaving her exposed to invisible monsters in the air. She took a deep breath, feeling confident. She had worked with Ebola, Marburg, Lassa Fever. The stress of handling H5N1 would be cake compared to that.
    The Biosafety-Level 4 laboratory’s floors, walls and ceiling are waterproofed and sealed. Surfaces are disinfected daily. The air is changed 20 times each day and filtered through a High Efficiency Particulate Air filtration system on the floor above, which removes particles 85 times smaller than the smallest virus. Solid and liquid waste is broken down, filtered and sterilized in a 20,000-liter liquid sterilization system in the bowels of the building. The facility had been built like a fortress, complete with bullet-proof windows and three 1,000-kilowatt generators to provide emergency backup power for all life safety, heating, cooling and ventilation systems.
    Only authorized personnel are allowed into the lab, and anything that goes into the lab is decontaminated or destroyed before it comes out.
    Their mission: Isolate the virus by growing it in a cell culture in vitro——“in glass,” in this case a test tube——in the cells of a canine kidney; this would confirm the infectiousness of the virus and provide a pure sample. Normally, this took about five days, but they would use the spin-amplification shell-vial method, shortening the assay to less than four days. After the lab scientists captured a virus isolate, a real-time PCR test would enable molecular detection and give them a complete genetic characterization. In other words, they would find out if they had H5N1 or something else.
    Additionally, the tissue samples had been collected from people in institutional settings, and so all of them had been given amantadine, a cheap, generic antiviral drug that is effective against most Type A influenza viruses. Wei and Ambrose, therefore, would also study the virus’ susceptibility to amantadine. H5N1 proved resistant to this drug in China, likely due to Chinese farmers repeatedly feeding it to their chickens in their water to prevent them from getting bird flu; over time, the virus evolved, adapted and grew resistant to the drug, thereby eliminating an important human defense.

The 2012-13 Avian Flu virus as seen in a negative-stained transmission electron micrograph collected from a canine kidney cell culture 18 hours after infection.(15)

    Wei once saw the 1918 Spanish Flu virus, reproduced from tissue collected from the frozen corpse of a Native Alaskan woman buried for about 80 years in permafrost near a town in which nearly nine out of 10 people had died. She had studied the virus using an electron microscope, which uses electrons to create an image of the target and can therefore generate magnification up to two million times. Seeing the infamous virus in robust detail, Wei had found it hard to believe that these tiny little spiked balls had killed more people in two years than all those who died in combat during the entire five years of World War I. Realizing this, it had been easy to see the virus as malicious. But viruses have no capacity for malice, she knew. A virus is simply a raw particle at the edge of life, an amoral machine tirelessly evolving and seeking new hosts to propagate itself in its ongoing struggle to survive in a brutal, competitive world.
    The facts so far, before she even began isolating and characterizing the virus sample, suggested that the agent in the test tube in her hand might very well be H5N1, a relative of the Spanish Flu. This meant that the Lab would be even more deluged with requests for influenza testing over the next three to six months. The long hours added up for laboratory workers, who would suffer exhaustion, back aches, muscle cramps. And one mistake could result in exposure—then it’s off to quarantine, or worse: infection.
    She took another deep breath to clear her mind and resumed the meticulous, laborious work of preparing the culture.
    Five days later, she finished isolating and characterizing the virus, confirming, on October 26, that H5N1 had reached Canada.