Archive · 26 Aug 2026
Why Doctors Call Swine Flu Seasonal H1N1
H1N1 is a type of flu virus that is spreading in several parts of India.
People often call it swine flu because the virus first identified in 2009 had some genes linked to viruses found in pigs.
But the virus now spreads mainly between people, like other seasonal flu viruses.
Eating properly cooked pork does not cause this infection.
Doctors therefore prefer names such as H1N1 influenza or influenza A(H1N1)pdm09.
The current increase does not mean the 2009 pandemic has started again.
Most people recover, but some can become seriously ill.
Older adults, young children, pregnant women and people with certain health problems face greater risks.
People with severe or worsening symptoms should seek medical care.
H1N1 cases are rising in Delhi, Bengaluru, Karnataka and other parts of India.
Delhi recorded 1,449 cases by August 12, compared with 229 during the same period in 2025; later reports cited 1,777 cases.
The virus is formally called influenza A(H1N1)pdm09 and has circulated as seasonal human influenza since the 2009 pandemic.
Seasonal H1N1 usually spreads from person to person through respiratory droplets and close interaction, not through properly cooked pork.
Doctors say the name change does not make H1N1 harmless, as influenza can cause pneumonia, hospitalisation and death, especially in high-risk people.
- Who
- People in India are being diagnosed with seasonal influenza A(H1N1)pdm09; health authorities and doctors are explaining the terminology.
- What
- H1N1 cases are rising, prompting renewed discussion about why the virus is commonly called swine flu.
- When
- Cases were reported rising in 2026, including Delhi data recorded by August 12.
- Where
- Delhi, Bengaluru, Karnataka, Gujarat and other parts of India.
- Why
- The term swine flu originated from the virus's links to pig influenza viruses in 2009, but the established virus now circulates primarily among humans.
Medical and Public-Health Terminology
Common Public Usage
What to call the virus
Medical and Public-Health Terminology
Doctors and the World Health Organization prefer H1N1 influenza, influenza A(H1N1) or A(H1N1)pdm09 because these names describe the human seasonal virus more accurately.
Common Public Usage
Many people continue to use swine flu because the phrase became embedded in public discussion during the 2009 pandemic.
Meaning of the current rise
Medical and Public-Health Terminology
Health authorities say rising cases reflect continued seasonal circulation and do not necessarily indicate a new or unusually dangerous virus.
Common Public Usage
The familiar term and rising case numbers can lead people to believe that a new swine-origin outbreak or a repeat of the 2009 pandemic is occurring.
Association with pigs
Medical and Public-Health Terminology
Medical guidance stresses that established seasonal H1N1 spreads mainly between humans and is not contracted by eating properly cooked pork.
Common Public Usage
The phrase swine flu may cause people to associate the illness with pork consumption or direct contact with pigs, creating confusion and stigma.
- Formal name
- Influenza A(H1N1)pdm09, also called H1N1 influenza.
- Delhi cases
- Delhi had 1,449 reported cases by August 12; later reports cited 1,777 cases.
- Earlier comparison
- Delhi recorded 229 cases during the corresponding period in 2025.
- Bengaluru activity
- Bengaluru was reported to have 300 to 400 active H1N1 cases and more than half of Karnataka's reported infections.
- Transmission
- Seasonal H1N1 generally spreads person to person through respiratory droplets, aerosols and close interaction.
- Pork safety
- Eating properly handled and cooked pork does not cause seasonal H1N1 influenza.
- Serious illness
- Influenza can cause severe respiratory disease, pneumonia, hospitalisation and death, particularly among high-risk groups.