Thousands of dead pigs floating down the Huangpu, a tributary of the Yangtze that provides most of Shanghai’s drinking water. 12 days after the first sighting of this “porcine death flow,” thousands of dead ducks lie on the banks of the Xiang, another tributary of the Yangtze. 2 days later, yet another similar scene along another river, such that in a span of 2 months, 20,000 animal carcasses have been collected by Chinese authorities, all victims of an as yet unidentified disease. This could easily seem like the beginning of a bizarre thriller but the truth, they say, is often stranger than fiction. These events represent actual happenings in China in the months of February and March 2013.
And it isn’t just animals who died. Three unrelated people were hospitalized at around this time; two died of pneumonia and one survived after spending days in the ICU. Unrelated events at first glance—except the government later announced that the victims had all been suffering from H7N9, a type of influenza that had previously only been found in birds.
The pigs, birds and people are unrelated as well, however. One of the two humans who died was a butcher and could have come into contact with pigs, while the one who survived had apparently been in contact with chickens. Except the virus identified as killing the adult hogs has never been known to affect humans. It, in fact, has never been known affect adult hogs either; only newborn piglets. There is nothing to be found in the either the bird, pig or human carcasses to explain how this virus became capable of killing adult pigs or humans.
Foreign Policy writer, Laurie Garrett, suggests an explanation: the H7N9 virus mutated, transformed from an avian flu to a swine flu, spread between the two species due to shared water sources, and from a swine flu, became human-transmissible.
On April 2nd, Reuters reported that China had announced four new patients affected by the H7N9 virus, but no evidence of inter-species or even human-to human transmission has been found yet. Despite the apparent lack of connection, reasons for worry, continue to abound.