India is witnessing a significant rise in seasonal influenza, with H1N1 emerging as the dominant strain in Delhi and health authorities stepping up surveillance across the country.
Delhi has recorded 1,777 H1N1 cases so far this year, including 114 infections reported on August 20. The capital has reported 2,602 influenza cases, comprising 2,392 Influenza-A and 210 Influenza-B infections. The H1N1 tally is substantially higher than the 229 cases recorded during the corresponding period last year.
Despite the increase, the Indian Council of Medical Research (ICMR) has said there is no evidence of a new or more dangerous H1N1 strain circulating in the country.
Delhi Steps Up Health Surveillance
The Delhi government has issued a public advisory urging residents to follow respiratory hygiene, avoid crowded places and seek medical advice if symptoms develop.
The government has placed 35 hospitals under special surveillance to monitor the seasonal influenza situation. AIIMS and the National Centre for Disease Control have been designated as referral laboratories.
Delhi Health Minister Pankaj Kumar Singh has said there is no need for panic, adding that hospitals have adequate beds, doctors, medicines and essential equipment.
Union Health Minister J P Nadda has also reviewed the preparedness of healthcare facilities, including beds, oxygen-supported facilities, ventilators, medicines and diagnostic capacity.
No New H1N1 Strain Detected
ICMR scientists have clarified that the current rise is not being caused by a newly emerged H1N1 strain.
The H1N1 viruses currently circulating in India have been identified as A/Missouri/11/2025 (H1N1) pdm09-like viruses, which remain well matched with the influenza vaccine strains recommended for the Northern Hemisphere.
Doctors say the virus continues to undergo small genetic changes, known as antigenic drift. Such changes can allow influenza viruses to infect people who may have less immunity to the circulating variant.
Three Viruses Circulating Across India
ICMR Director Rajiv Bahl said India’s strengthened post-Covid surveillance system is allowing authorities to monitor respiratory viruses in real time.
Surveillance currently indicates significant circulation of Influenza A/H1N1, Influenza B and COVID-19.
India has around 73 laboratories participating in the respiratory surveillance system, with samples from severe respiratory infections and other cases tested regularly.
Doctors Report More Complications
While most influenza infections remain mild, doctors in Delhi are reporting an increase in patients with complications.
Doctors have reported cases involving pneumonia, breathing difficulties, oxygen requirements and gastrointestinal symptoms such as diarrhoea and stomach cramps.
Experts say severe disease remains more likely among young children, elderly people, pregnant women and people with underlying medical conditions or weakened immunity.
Some doctors have also pointed to increased travel, monsoon conditions, pollution and reduced population immunity as factors that could be contributing to the rise.
What Are the Symptoms?
Common symptoms of H1N1 and seasonal influenza include fever, cough, sore throat, headache, body ache and fatigue. Some patients may also develop breathing difficulties, diarrhoea and stomach cramps.
People experiencing persistent or worsening symptoms have been advised to seek medical attention rather than self-medicate.
What Precautions Should People Take?
Health authorities have urged people to wear masks in crowded places, cover their mouth and nose while coughing or sneezing, wash their hands regularly and avoid close contact with people suffering from respiratory infections.
People have also been advised to avoid touching their eyes, nose and face, maintain adequate fluid intake and seek timely medical advice if symptoms develop.
Antibiotics do not treat influenza because H1N1 is a viral infection. Antiviral medicines such as oseltamivir may be recommended for people with severe illness or those at higher risk of complications, but they should be taken only on medical advice.
When Should You Seek Medical Care?
People should seek urgent medical attention if they develop breathing difficulties, chest pain, severe weakness or rapidly worsening symptoms.
For most healthy people, seasonal influenza remains self-limiting. However, vulnerable groups should seek medical advice early rather than waiting for symptoms to become severe.
