only about 9 percent of the confirmed H7N9 cases in China have walked out of hospital, cured of their infections; one has been asymptomatic; and the remainder are still hospitalized, many suffering multiple organ failure and illnesses from which they are unlikely to recover.
In 1985, researchers showed that two key mutations in bird flu viruses occurring simultaneously could switch them to forms capable of spreading among mammals. When H5N1 appeared in Hong Kong in 1997, local flu experts took some comfort in discovery that the virus had not made those mutational changes, so spread among people was unlikely. And since that time the WHO has nervously monitored strains of the virus emerging worldwide, looking for evidence that these mutations had been made. Thankfully, they have not. But in 2012, two labs working independently -- one in the Netherlands, the other in the United States -- controversially deliberately made those mutations in H5N1 under controlled conditions, confirming that a bird virus with those gene switches could spread from one ferret to another, through the air coughed between them.
The H7N9 virus now circulating in China has those mutations.
Mapping the H7N9 avian flu outbreaks
Where are the 104 human cases confirmed so far, and where might the virus go next?
“This finding implies that H7N9 viruses have partially acquired human receptor-binding specificity. All of the H7N9 human isolates examined contained a lysine residue at position 627 in the PB2 protein. It is well known that this lysine residue contributes to the replication and transmission of avian influenza viruses in mammalian hosts. It is likely that the acquisition of this lysine in H7N9 viruses during their replication in human hosts has significantly contributed to their virulence and lethality in humans.”
Possible enormous risk of the H7N9 influenza
We think that the H7N9 influenza outbreak is of enormous
risk for the following reasons... (8 reasons follow)
5 Possible mild risk of the H7N9 influenza outbreak
We do not exclude completely the possibility that the H7N9 will disappear naturally, or maintain its low pathogenicity in birds and limited transmission ability in humans for a long period, without forceful scientific control measures. However, such a mild scenario of the outbreak evolution is of less possibility than the very or extremely severe scenario describe above.
"Known as novel coronavirus or hCoV-EMC, the virus was first detected in mid-2012 and is a cousin of Severe Acute Respiratory Syndrome (SARS)... The new virus is different from SARS, in that it causes rapid kidney failure.
The strain is shrouded in mystery, and the World Health Organisation does not yet know how it is transmitted or how widespread it is.
A 73-year-old Saudi man died in Germany in March from the lethal new virus.
He had been travelling in Pakistan and Saudi Arabia before falling ill, and was transferred to Munich from Abu Dhabi on March 19 "
U.S. health officials say last year was the worst ever for West Nile virus deaths. The final tally reported Monday was 286 deaths — or two more than the record set in 2002.
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