INFLUENZA A. In China, the first human case tested positive for the H3N8 bird flu virus. He had a fever and other symptoms. You should not worry according to virologist Jean-Claude Manuguerra, but he calls for surveillance. What is the H3N28 virus? What are the risks for humans? Info.
[Mis à jour le 29 avril 2022 à 14h12] On April 26, China announced that it had detected the first human case of H3N8 avian flu. The Chinese Ministry of Health said it was a four year old boy, living in Henan province (central China). He tested positive for the H3N8 strain after being hospitalized in early April for a fever and other symptoms. “This is the first time, at least in the time of modern virology, that we have had a passage of H3N8 in humans” commented Jean-Claude Manuguerra, virologist, trained veterinarian and head of the Biological Emergency Response Unit at the Institut Pasteur interviewed by TF1 April 28. “It’s only one case”, emphasizes Jeanne Brugère-Picoux, veterinarian and member of the National Academy of Medicine, whom we contacted. The child would have been contaminated after contact with birds. “JI don’t think you should worry more than that. On the other hand, it is a signal that must be taken into account, and thatit is necessary to monitor in general the passage of these viruses to humans” recommends Dr. Manuguerra.
What is the H3N8 flu virus?
H3N8 is a subtype of the influenza A virus or bird flu. This type of virus has so far affected horses, birds and dogs, as well as pinnipeds (seals, sea lions and walruses). Avian influenza is a disease of animal origin caused by A strains of the influenza virus. “Avian influenza is a viral disease that affects birds, and whose mortality rate is very high in farmed birds (chickens, geese, etc.)“ recalls the Pasteur Institute.
The family of the H3N8 positive child raise chickens and live in a area populated by wild ducks. The H3N8 virus is thought to be the cause of 26% of bird flu infections in wild ducks according to one study published in 1997. The boy was infected directly by the birds, the ministry said, adding that tests carried out on people close to the patient did not reveal “no abnormality“. This case results from a “occasional inter-species transmission” and “the risk of large-scale transmission is low”. The Ministry of Health in China nevertheless called for do not approach dead or sick birds. You should know that not all avian influenza viruses are transmitted to humans. Of 144 strains of avian influenza A viruses, four had so far caused human infections: H5N1, H7N3, H7N7 and H9N2. “The H5N1 bird flu virus was first spotted in 1997, during an outbreak in Hong Kong, killing six people“says the Pasteur Institute. “The spread of infection among birds increases the likelihood of the appearance of a new influenza virus in the human population, develop the Institute. To date, the bird flu virus has not been transmitted from person to person.
What are the symptoms for H3N8 avian flu?
Symptoms of bird flu include:
- high fever (above 38°C)
- fatigue,
- muscle aches,
- cough and sore throat.
In the case of the four-year-old child who tested positive for the H3N8 strain, “He was hospitalized in early April for a fever and other symptoms“according to the Ministry of Health in China, which did not give more details.
Sources:
-AFP
– Co-infection of wild ducks with influenza A viruses: distribution patterns and biological significance, April 23, 1997. Journal of Virology
– Avian flu, Institut Pasteur