A new strain of the H7N9 bird flu — a version that has never before been seen in humans — is beginning to spread in China. Experts first identified the strain on Sunday, and the Chinese government has linked it to 11 cases and four deaths since then.
It’s not clear exactly how many people may have been sickened by the current outbreak, and scientists aren’t yet sure if this flu can spread from human-to-human contact. But health experts are now rushing to figure out more about the source of the virus so they can assess its potential to spark a pandemic:
Just days after authorities in China announced they had identified cases of H7N9, flu experts in laboratories across the world are picking through the DNA sequence data of samples isolated from the patients to assess its pandemic potential.
One of the world’s top flu experts, Ab Osterhaus, who is based at the Erasmus Medical Center in The Netherlands, says the sequences show some genetic mutations that should put authorities on alert and entail increased surveillance in animals and humans. [...]
“We can’t be complacent. We have to be cautious,” [Wendy Barclay, a flu virology expert at Britain's Imperial College London] said, stressing that other H5 and H7 flu subtypes have been able to mutate from LPAI to the more dangerous highly pathogenic avian influenza (HPAI) as they circulate in various hosts, particularly in chickens.
Finding that source, and tracking the genetic mutations to see if, how and when this new strain might gain the ability to spark a human pandemic are now the priorities for researchers in China and around the world, Barclay and Osterhaus said.
Other strains of bird flu can be spread either from bird to bird, or from bird to human — but not from human to human. Luckily, there’s no evidence so far that H7N9 is spreading between humans. But scientists will continue to carefully monitor the situation, since the virus could mutate into different and more dangerous forms.
Scientists aren’t sure which type of animal is providing the source for the virus, so health officials have warned that butchers, chicken breeders, and employees in the meat processing industry could all be at risk for contracting bird flu. Recently, dead pigs and dead ducks have mysteriously flooded China’s river — and it’s not yet clear if that’s somehow connected to the H7N9 outbreak. Chinese authorities are still unable to explain the deaths of those animals.
China has a mixed history with dealing with public health outbreaks. When SARS originated in the country in 2003, Chinese officials first attempted to cover it up, withholding data about the the outbreak in order to prevent widespread panic. That infection ultimately spread to 8,000 people around the world.