BEIJING—Another novel strain of avian influenza has made the leap from birds into humans. But virologists believe that the deceased patient is likely to have been an isolated case.
On 30 November, a 73-year-old woman from Jiangxi province in southern China was hospitalized with severe pneumonialike symptoms; she succumbed to respiratory failure on 6 December. Several days later, Chinese authorities notified the World Health Organization (WHO) that doctors had isolated the H10N8 virus from the patient’s blood. While H10 viruses have popped up on occasion in people, this is the first known human infection of H10N8, says Malik Peiris, a virologist at the University of Hong Kong.
Flu experts are not hitting the panic button. For starters, they aren’t convinced that H10N8 was the primary cause of the woman’s death. She was a cancer patient whose thymus had been removed. The thymus produces T cells, which help fight off infections. “Her immune system was already severely compromised,” says George Gao, deputy director-general of the Chinese Center for Disease Control and Prevention (China CDC) here. “There’s no evidence yet this [virus] is the direct cause of death.” For that reason, Peiris says, “I don’t think it necessarily means we will see many more cases.” H10N8 may end up following a similar pattern to another newly emergent strain, H6N1. It was detected in May in Taiwan, in a woman who recovered after antiviral treatment. Since then, no further human infections of H6N1 have been reported.
Still, public health officials are taking no chances with H10N8. China CDC has advised Jiangxi authorities to temporarily close a live poultry market where the woman is believed to have contracted H10N8. And scientists are now probing the H10N8 genome for “any unusual features, and how similar it is to H7N9,” Peiris says. H7N9 is seen as a graver threat: That strain has infected 143 people and killed 45 since emerging in southern China in March. Four of those cases were reported in the past month. “The more cases there are, the more chances there are for the virus to adapt to human transmission,” Peiris says. “That is the biggest concern.”