• Infections typically result from direct 
• animal-to-human transmission
• H5 subtype is particularly noteworthy for causing severe outbreaks
• India recently reported a human case of H9N2 bird flu in a child from West Bengal
• Infection can lead to upper respiratory tract symptoms such as shortness  of breath, cough, sore throat, or a runny or stuffy nose

By Sheain Fernandopulle 

The World Health Organisation (WHO) has directed Sri Lanka to go on alert in the wake of the recent detection of avian influenza or bird flu in humans in neighbouring countries like India, Daily Mirror learns.

Bird flu, or avian influenza, is an infectious disease caused by influenza viruses that primarily affect birds but can also infect other animals and humans. 

The disease can be caused by various strains of influenza viruses, with the H5 subtype being one of the most significant due to its potential to cause severe outbreaks.

Main avian influenza strains include H5, H7, H9, and H10. Key human-infecting strains are H5N1, H5N8 (rarely), H7N9, H7N2, H7N3, H7N7, H9N2, and H10N8. H5N1 and H7N9 are particularly severe, causing high mortality. H9N2 and H10N8 typically cause milder illness. Continuous surveillance is vital due to the potential for these viruses to mutate and cause pandemics.

The case in point is that India reported a recent case of human infection with the avian influenza A(H9N2) virus in a child from West Bengal. This is only the second reported case of H9N2 in humans in India, with the first occurring in 2019. 

The child had exposure to poultry and has since recovered.

In addition, in May 2024, Australia confirmed its first human case of bird flu, specifically the H5N1 strain, in a child who had recently travelled from India while in the United States, three human cases of H5N1 bird flu were reported in 2024, all linked to dairy cows in Texas and Michigan. 

These cases were the result of direct animal-to-human transmission, with no evidence of human-to-human spread. 

Commenting on the situation, Consultant Virologist at the Medical Research Institute (MRI) Dr. Jude Jayamaha told Daily Mirror that the various strains of avian influenza are of significant concern due to their potential to mutate and adapt to new hosts, including humans. 

“In light of the global scenario, Sri Lanka has developed the capacity to detect H9, H7 & H5 bird flu cases in humans, Furthermore, the routine influenza surveillance in sentinel site hospitals is capable of detecting any suspected case of bird flu in humans,” he pointed out.

Elucidating further on the virus, Dr. Jayamaha pointed out that birds shed the virus in their saliva, mucus, and faeces and consequently, people or animals with close, unprotected contact with infected birds or contaminated environments can become infected.

“While it is rare for people to inhale the virus or get enough of it in their eyes or mouth to fall ill, those in close contact with animals remain at risk. This infection can lead to upper respiratory tract symptoms such as shortness of breath, cough, sore throat, or a runny or stuffy nose, Dr. Jayamaha noted.

“Like with other viruses, people can also experience muscle or body aches, headache, fatigue, fever or, as was seen in farmworkers, conjunctivitis,” he added.

As such, authorities recommend that people working with animals wash their hands with soap and water and wear personal protective equipment. This includes fluid-resistant coveralls, a waterproof apron, a safety-approved respirator, properly fitted goggles or face shield, a head or hair cover, gloves, and boots.