During a telephone press briefing on Wednesday, Wenqing Zhang, head of WHO’s global influenza department, told reporters “Constant change is the nature of all influenza viruses – this makes influenza a persistent and significant threat to public health.”
The UN health agency says that the bird flu strain currently found in China, H7N9, has not been reported in poultry outside the country, although nations bordering China have increased their surveillance.
But there is also concern over the number of outbreaks of the H5 avian bird flu strain in poultry and wild birds across Europe, Asia, and Africa. With the outbreaks of the H5 strain, the risk to humans appears to be low for now, but WHO says vigilance is vital.
China has a fifth wave of human H7N9 cases
China is currently experiencing the fifth wave of human H7N9 bird flu cases since it was first detected in humans 2013. While the evidence is limited, human-to-human transmission of the virus cannot be ruled out. Since October 2016, WHO has confirmed 460 human H7N9 bird flu cases in China.
These increases in cases have been referred to as waves. WHO defines these waves as beginning on 1 October until 30 September of the following year. Thus, currently, the increase in human cases is referred to as the fifth wave (1 October 2016 through 30 September 2017).
In about 7.0 percent of those fifth wave cases, scientists have identified genetic changes suggesting the viruses are resistant to Tamiflu, the recommended treatment for disease and the drug being stockpiled around the world in preparation for a flu pandemic. However, WHO says there is no reason to change the recommended treatment for now.
The WHO noted that “so far, only H5N1 and H5N6 cause human infections”, but said it was working with the OIE to monitor the viruses’ evolution.
