H7N9: Even More Reasons to Worry

Before you roll your eyes at yet another H7N9 post, consider this: The numbers may be just a drop in the bucket compared to the population at large (as of today the number of infections had risen to 108 and the death toll was at 22), but WHO officials are now claiming that the illness "one of the most lethal" of its kind and is more easily transmissible to humans than an earlier strain that has killed hundreds around the world since 2003," according to an article in The Guardian.

On the bright side, officials still maintain that they have not seen any evidence of "sustained transmission between humans," but this is hardly reassuring considering how little is understood of the illness.

What does seem to be clear is that the elderly are particularly susceptible - half of the more serious cases are in patients over 60 - and despite reports that a number of patients claimed to have had no contact with poultry whatsoever before contracting the illness, researchers are citing a "dramatic slowdown in reported cases in Shanghai" since the city's live poultry markets were shut down.

Nevertheless questions are still swirling as to how the virus has mutated to this stage and what might happen next. Pulitzer-prize winning science journalist Laurie Garrett has written a must-read article on this subject, and the implications are extremely unsettling:

Influenzas are named according to the specific nature of two proteins found on the virus -- the H stands for hemaggluntinin and the N for neuraminidase. These proteins play various roles in the flu-infection process, including latching onto receptors on the outside of the cells of animals to transmit the virus into their bodies. Those receptors can vary widely from one species to another, which is why most types of influenza viruses spreading now around the world are harmless to human beings. As far as any scientists know, the H7N9 forms of flu have never previously managed to infect human beings, or any mammals -- it is a class of the virus found exclusively in birds. It is therefore extremely worrying to find two people killed and one barely surviving due to H7N9 infection.

One very plausible explanation for this chain of Chinese events is that the H7N9 virus has undergone a mutation -- perhaps among spring migrating birds around Lake Qinghai. The mutation rendered the virus lethal for domestic ducks and swans. Because many Chinese farmers raise both pigs and ducks, the animals can share water supplies and be in fighting proximity over food -- the spread of flu from ducks to pigs, transforming avian flu into swine flu, has occurred many times. Once influenza adapts to pig cells, it is often possible for the virus to take human-transmissible form. That's precisely what happened in 2009 with the H1N1 swine flu, which spread around the world in a massive, but thankfully not terribly virulent, pandemic.

If the pigs, people, and birds have died in China from H7N9, it is imperative and urgent that the biological connection be made, and extensive research be done to determine how widespread human infection may be. Shanghai health authorities have tested dozens of people known to have been in contact with Wu and Li, none of whom have come up positive for H7N9 infection. Assuming the tests are accurate, the mystery of Li and Wu's infections only deepens. Moreover, if they are a "two of three," meaning two dead, of three known cases, the H7N9 virus is very virulent.

Putting it simply: Scientists are still in the dark about how H7N9, which was previously not known to affect humans, has made the interspecies jump to humans and if it is, in fact, affecting other species (i.e. pigs or dogs), or, most troubling of all, if it's only a matter of time before it mutates into a virus that can be easily passed from one person to another.

We'd like to think that health officials will have a well thought-out plan, but experts are already saying how "problematic" producing a H7N9 vaccine will be - due to "difficulties in the production and manufacturing process" it could take up to eight months before it becomes widely available - just hope to god you don't fall ill in the meantime.

Photo: cp24.com