In what is possibly the first known case in a human, a Chinese woman who died in November was co-infected with H3N2 seasonal flu and a H10N5 flu virus that is genetically related to avian subtypes, according to health authorities in the country.
The National Administration for Disease Control and Prevention posted the details on its website, which were translated and posted by FluTrackers, an infectious disease news message board.
The 63-year-old’s symptoms began on 30 November, and included cough, fever and sore throat. Officials said she had underlying health conditions.
CIDRAP reports that a few days later, she was admitted to hospital when her condition deteriorated, and she died on 16 December.
During routine surveillance on samples from fatal cases, lab scientists in Zhejiang province isolated H3N2 seasonal flu, along with the H10N5 subtype.
Repeat testing at the China Centres for Disease Control and Prevention (CDC) confirmed the findings.
Investigations involving the woman’s close contacts found no suspicious cases, with nucleic acid tests being negative for people who were screened.
Scientists also conducted complete sequencing of the H10N5 virus and found that it was completely of poultry origin, without the capacity to easily infect humans.
Officials said the patient’s illness is an example of cross-species transmission from poultry to humans, but the report did not say how she may have contracted the H10N5 virus.
Officials said the overall health risk was low and there was no sign of human-to-human transmission.
Hong Kong’s Centre for Health Protection said last week that it was monitoring developments with the case.
“All novel influenza A infections, including H10N5, are notifiable infectious diseases in Hong Kong,” it added.
First H10N5 infection in a person
China has reported a few human H10 cases before. In 2013 officials reported a fatal case involving a H10N8 virus that carried genes from H9N2 avian flu, which circulates in Chinese poultry and occasionally infects humans.
H10 has also been detected in Australian slaughterhouse workers and in Egyptian infants.
In 2021, China reported an H10N3 avian flu case in a man from Jiangsu province, the first known case involving the strain. He had no clear exposure to poultry, and the virus hadn’t recently been detected in local poultry.
Information on influenza A virus subtypes from the US Centres for Disease Control and Prevention said most H10 infections in people have involved exposure to infected poultry.
CIDRAP article – China reports woman’s death from H3N2-H10N5 flu co-infection (Open access)
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