H7N9 Now Spreading Human-to-Human
An ominous development in the new bird flu is the first apparent, well-documented case of the virus being transmitted from human to human. Laurie Garrett, who reports almost daily for Foreign Policy magazine on the new bird flu strain, notes that the victim who carried the virus from China to Hong Kong has spread it to people caring for him:
Three of the victim’s healthcare workers have developed flu symptoms, suggesting both that this epidemic has crossed country borders and that it can pass from person to person. Even more distressing, the healthcare workers wore full protective gear.
There are also many other cases where the human victims say they have no contact with birds. According to Zheng Guan of China’s Centers for Disease Control, “Forty percent of the patients had no contact with poultry or environments where birds were located.” And most of those categorized as “having contact” merely bought or ate chickens in exactly the manner that tens of millions of Chinese do daily.
If H7N9 is behaving like H1N1, it’s “almost too terrible to think about.”
In a separate article, Garrett writes about the two directions the virus could now take: one is like H5N1, which is deadly to most humans, but hard to catch; the other is like H1N1, the so-called swine flu (actually a bird flu that mutated in pigs), that spread rapidly through the human population but was not nearly as lethal.
H7N9 appears to be as lethal as H5N1 and may be mutating rapidly to behave like H1N1. Garrett calls this “almost too terrible to think about.”
The H7N9 flu now evolving before humanity’s eyes in China has killed 18 percent of the 108 people with lab-confirmed infections as of April 22. That’s a lethality about nine times the mortality rate of the Great Influenza of 1918-19, which claimed at least 50 million lives by lowball estimate, and up to 100 million based on extrapolation from colonial-era records in India and African countries …
… More worrying, 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.
While H1N1 was less deadly to humans, national and corporate interests prevented the world from acting in a concerted, cooperative fashion. Instead, if the same kind of scenario unfolds in this case:
Solidarity between countries and economic powers, corporations, even many health authorities will yield in a pandemic to nationalism, company and private interests, and jockeying for power, profit and influence.
Meanwhile, the virus is adapting – and apparently on an almost-daily basis. In China, officials are trying to walk a fine line between giving accurate information and not causing mass panic.
Another problem: we don’t even know that H7N9 really is a bird virus. Of the 88,000 birds, both wild and in the chicken markets of China, only 39 have tested positive for the virus. H5N1, by comparison, spread rapidly through the chicken population, killing almost 100 percent of the birds in any given population.
Overall, the evidence from H5N1 is that a true avian flu is brutally contagious and deadly to vulnerable bird species, but rarely infectious to, or between, mammals.
… In contrast, the new H7N9 virus is officially designated [as] “low pathogenicity avian influenza” because it causes no apparent life-threatening disease in birds. The new Chinese virus seems to have transitioned from avian flu to something else: an infection of minor consequence to birds, but often lethal for human beings.
… As [one researcher] told me, “This virus really doesn’t look like a bird virus anymore; it looks like a mammalian one.”
But where did it come from. Pigs are one of the best animals for virus to mutate into a mammal form (as we saw in H1N1, which was incubated at an American factory farm). But so far, no infected pigs or other mammals have been found, according to the Chinese CDC.
Indications are that this is not basically a bird flu at all, but a mammalian flu.
Another mystery: In the case of H5N1 and other dangerous bird flus, most of the transmission from bird to human have occurred in rural settings – where people are handling birds in their backyards and at chicken markets. But in the case of H7N9, the reverse is the case. No infected rural flocks or farmers have been found. But the virus has been spreading in one of the world’s biggest cities: Shanghai.
And is it pure coincidence that at the same time that H7N9 was showing up in Shanghai, thousands of dead pigs were found floating down the river that runs through the city? We have no idea.
More and more, the indications are that this is not basically a bird flu at all, but a mammalian flu, and that the birds who have tested positive for H7N9 have simply been recipients of the virus and appear to be largely immune to its effects.
Whatever animal harbors the virus, it must be an urban-adapted creature, and ubiquitous from China’s nearly tropical south to its wintry north. And because of the presence of those two crucial “mammalian” mutations, it must have an internal ecology permissive to mammal-infectious forms of flu — which would seem to exclude birds, insects, amphibians — all but mammals.
There are many other mysteries. For example:
- Why is this virus affecting so many men over the age of 60? Why are they so vulnerable, compared to women and children?
- What caused thousands of swallows to fall out of the sky in Nanjing? Is there any connection?
- Have many more humans than the 108 confirmed cases been infected than we know about? Have they only had mild symptoms?
And most important: How will China and the rest of the world react if and when H7N9 is confirmed as a global pandemic?