The risk of sustained human-to-human transmission of H7N9 bird flu in China is low, the World Health Organization said on Wednesday, but a surge in human cases there is worrying and requires constant monitoring.
Outbreaks of H5 bird flu strains in poultry and wild birds across Europe, Africa and Asia are also raising concern, the WHO said, and while the human risk of these outbreaks is also low for now, 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 program, told reporters on a telephone briefing.
China is currently seeing a fifth wave of H7N9 bird flu in humans – a virus that was first detected in people in 2013.
Since October 2016, a total of 460 laboratory-confirmed human H7N9 infections have been reported in China, a figure that exceeds 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.