WHO eases China bird flu fears in humans

The risk of sustained human-to-human transmission of H7N9 bird flu in China is low, the World Health Organisation said on Wednesday, but a worrying surge in human cases there requires constant monitoring.

Outbreaks of H5 bird flu strains in poultry and wild birds across Europe, Africa and Asia were also raising concern, the WHO said, and while the human risk of these outbreaks is also low, vigilance is vital.

“Constant change is the nature of all influenza viruses — this makes influenza a persistent and significant threat to public health,” Wenqing Zhang, head of the WHO’s global influenza programme, said.

China is seeing a fifth wave of H7N9 bird flu in humans. Since October 2016, 460 laboratoryconfirmed human H7N9 infections have been reported in China, a figure that exceeds those of previous seasons and accounts for more than a third of total cases since 2013.

So far, H7N9 has killed around a third of people it has been known to infect.

The WHO says there is no evidence that the epidemiological characteristics of human infections — such as the age and gender of those infected, their exposure history and the case fatality rate — are changing. About 7% of human cases of H7N9 in 2017 were showing resistance to the antiviral drugs known as neuraminidase inhibitors, Zhang said. These medicines, including the well-known drug Tamiflu, or oseltamivir, are recommended to treat flu.

The WHO said it was watching these developments, but there was no reason to recommend changes in how patients are treated.