WHO's H5N1 Alert Gains Urgency As India Battles Seasonal Flu Surge

New Delhi: The World Health Organization’s (WHO) latest appeal for Asia-Pacific countries to strengthen preparedness against highly pathogenic avian influenza A (H5N1), assumes added significance for India, which is simultaneously reporting recurring bird flu outbreaks and witnessing a surge in seasonal influenza A (H1N1) cases.

Over 150 influenza experts, laboratory scientists and public health officials participated in the recently held 19th Biregional Meeting of National Influenza Centres and Influenza Surveillance, jointly organised by WHO’s Southeast Asia and Western Pacific regional offices, from August 25 to August 27. The meeting examined ways to convert surveillance data into faster public health decisions, amid the continuing spread of H5N1 among birds, and the possibility of animal-to-human spillover.

Concern For India

For India, the concern is not merely theoretical. Avian flu outbreaks have been reported in poultry and other birds in the past. The Central government had reported avian influenza outbreaks in 2024 and 2025. More recently, 11 H5N1 outbreaks were reported in poultry farms in Kerala, involving the deaths of over 54,000 birds, with thousands more culled as a precaution.

The risk of H5N1 to the general population remains low, but India’s recent history shows why sustained surveillance is essential. According to WHO data, between 2020-2024, India reported one death, and two deaths in 2025, due to the avian influenza A(H5N1).

Genetic analysis indicated the virus belonged to clade 2.3.2.1a, a lineage circulating in the region. However, no confirmed human H5N1 case has been reported from India so far in 2026.

Laboratory Networks, Early-Warning Systems

Public health experts say the simultaneous experience of seasonal influenza and recurring avian outbreaks demonstrates the importance of strong laboratory networks and early-warning systems.

“First, we need to understand what H5N1, also known as “avian influenza” or “bird flu”, is? It is a subtype of influenza virus that infects birds and mammals, including humans in rare instances. Infections in humans is mostly linked to close contact with infected birds and other animals and contaminated environments. This virus does not appear to transmit easily from person to person, and sustained human-to-human transmission has not been reported,” said Dr Manali Agarwal, infectious disease expert and medical microbiologist, to ETV Bharat on Saturday.

Dr Manali Agarwal (ETV Bharat)

According to Dr Agarwal, most human H5N1 cases are associated with the direct handling of infected poultry, slaughtering or preparing sick poultry for consumption, consumption of uncooked poultry products like raw blood, or close contact with live poultry. In bird-to-human transmission, the likely entry portal for the virus is via the respiratory tract, the gastrointestinal tract, or the conjunctiva.

“Most patients with influenza H5N1 virus present with symptoms of fever, cough, and shortness of breath and radiological evidence of pneumonia. Frequently occurring non respiratory symptoms include diarrhea, vomiting, and abdominal pain. Surveillance and testing are important to understand which influenza viruses are circulating and their effect on human health. This is critical for pandemic preparedness and for protection of citizens,” Dr Agarwal, Ex-AIIMS, Delhi said.

The WHO has stressed that effective One Health coordination — linking human, animal and environmental health authorities — is critical to detecting zoonotic threats before they spread further. The organisation also noted that sustained human-to-human transmission of H5N1 has not been reported, but influenza viruses can evolve, making continued monitoring crucial.

H5N1: A Warning About A Different Influenza Threat

Talking to ETV Bharat, another renowned health expert and past president of Asian Society of Emergency Medicine Dr Tamorish Kole said the call given by the global health watchdog should be seen not as a response to the H1N1 situation, but as a warning about a different influenza threat.

“H1N1 is a seasonal human influenza virus that spreads efficiently from person to person, whereas H5N1 is primarily an avian influenza virus that can occasionally spill over into humans from infected birds or contaminated environments. For India, this is particularly important because of its large poultry sector, backyard poultry, live-bird markets, migratory-bird pathways and frequent human–animal interfaces,” said Dr Kole.

Dr Tamorish Kole (ETV Bharat)

H5N1 has already been detected in Indian birds, including the highly pathogenic clade 2.3.4.4b viruses, creating opportunities for human exposure and, potentially, viral adaptation.

“The simultaneous presence of H1N1 therefore makes influenza surveillance more important, not less, with hospitals and laboratories needing to distinguish routine seasonal influenza from unusual influenza A infections. India should continue strengthening a One Health approach, integrating human, veterinary and environmental surveillance so that any zoonotic transmission is detected early and contained before sustained human-to-human transmission can emerge,” Dr Kole stated.

Laboratory-Confirmed Human H5N1 Infections

Referring to the two previous H5N1 infections in India, Dr Kole said, “India has recorded three laboratory-confirmed human H5N1 infections since 2003, and all three have been fatal. The first was a child in Haryana in 2021 who developed severe respiratory illness and Acute Respiratory Distress Syndrome (ARDS) and died, while two further fatal human infections were reported in 2025. Although the number of cases remains extremely small, the high severity of documented H5N1 infection is a serious concern.”

Globally, WHO has reported hundreds of confirmed human infections with a historically high case-fatality proportion, although this should not be interpreted as the expected fatality rate in a future widespread outbreak, he said.

“Importantly, there is currently no evidence of sustained human-to-human transmission, and the overall public-health risk remains low. The concern is therefore not that India is facing an H5N1 pandemic today, but that every human infection provides an opportunity for the virus to adapt or acquire mutations that could alter its transmissibility; the three fatal cases should consequently be regarded as a strong surveillance and preparedness signal, not a reason for public panic,” added Dr Kole.

At the WHO regional meeting, India showcased how integrating influenza surveillance with the Integrated Health Information Platform (IHIP) provides near-real-time data for analysis and visualisation, supporting faster detection of influenza trends and outbreaks.

As India deals with H1N1 while continuing to monitor H5N1 outbreaks in birds, experts say surveillance systems must ensure that an unusual influenza signal is rapidly identified, investigated and acted upon.

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