In a follow-up on the first ever human infection with H7N4 avian influenza reported worldwide in China, the World Health Organization (WHO) released an update with more details.
The case-patient was a 68-year-old woman from Jiangsu Province with pre-existing coronary heart disease and hypertension and she developed symptoms on 25 December 2017. Seven days later, she was admitted to a local hospital for treatment of severe pneumonia and was discharged after 21 days.
On 12 February, the Chinese Center for Disease Control and Prevention (China CDC) confirmed that the case-patient’s samples were positive for avian influenza A(H7N4). The NHFPC confirmed the diagnosis on 13 February 2018. The case-patient had reported a history of exposure to live poultry before onset of symptoms.
Genetic sequencing of this A(H7N4) virus shows that all the virus segments originated from avian influenza viruses. This virus is sensitive to adamantanes and neuraminidase inhibitors based on genetic sequencing.
Twenty-eight close contacts of the case-patient have been under medical observation. Among close contacts, no abnormal findings have been found and all throat swabs from her contacts have tested negative.
This is the first report of a human case of avian influenza A(H7N4) infection globally and the case reported exposure to live backyard poultry before illness onset. Genetic analysis of this influenza A(H7N4) virus indicates that it is of avian origin.