HQ Team
June 12, 2024: A four-year-old child in India has been detected with avian influenza A(H9N2) in the Eastern state of West Bengal, the World Health Organization reported.
The child was previously detected with hyper-reactive airway disease and went to a pediatrician with fever and abdominal pain on 26 January 2024. Its office was notified of the case on May 22.
On 29 January, the patient developed seizures and was brought to the same pediatrician. On 1 February, the patient was admitted to the paediatric intensive care unit of a local hospital due to the persistence of severe respiratory distress, recurrent high-grade fever and abdominal cramps, according to a WHO statement.
The child was diagnosed with post-infectious bronchiolitis caused by viral pneumonia. On February 2, the patient tested positive for influenza B and adenovirus at the Virus Research and Diagnostic Laboratory in West Bengal.
Respiratory distress
The patient was discharged from the hospital on February 28, 2024. Soon after, on March 3, the child developed severe respiratory distress. He was referred to another government hospital and was admitted to the paediatric ICU and intubated.
A nasopharyngeal swab was sent to the Kolkata Virus Research and Diagnostic Laboratory and tested positive for influenza A (not sub-typed) and rhinovirus. The same sample was sent to the National Influenza Centre at the National Institute of Virology in Pune for sub-typing.
The sample was sub-typed as influenza A(H9N2) through a real-time polymerase chain reaction. “The patient was discharged on May 1 from the hospital with oxygen support. Information on the vaccination status and details of antiviral treatment were not available at the time of reporting.”
The child was exposed to poultry at home and in the surroundings, according to the WHO statement.
Avian, swine influenza
This is the second human infection of avian influenza A(H9N2) virus infection notified to WHO from India, with the first in 2019. Further sporadic human cases could occur as this virus is one of the most prevalent avian influenza viruses circulating in poultry in different regions, the WHO stated.
Animal influenza viruses normally circulate in animals but can also infect humans. Infections in humans have primarily been acquired through direct contact with infected animals or indirect contact with contaminated environments.
Depending on the original host, influenza A viruses can be classified as avian influenza, swine influenza, or other types of animal influenza viruses.
Avian influenza virus infections in humans may cause diseases ranging from mild upper respiratory tract infections to more severe diseases and can be fatal. Conjunctivitis, gastrointestinal symptoms, encephalitis and encephalopathy have also been reported.
‘Spread is low’
Most human cases of infection with avian influenza A(H9N2) viruses are exposed to the virus through contact with infected poultry or contaminated environments. Human infection tends to result in mild clinical illness.
Available epidemiological and virological evidence suggests that this virus has not acquired the ability to be sustained in transmission among humans. Thus, the likelihood of human-to-human spread is low.
According to the WHO, the public should avoid unprotected contact with live poultry, live animal markets or farms, and surfaces that might be contaminated by poultry droppings.
