Bengaluru: H1N1 influenza is drawing renewed attention as cases rise in Bengaluru and Delhi, but health experts say there is no clear evidence that infections are more dangerous in one city than the other.

Delhi had reported 1,777 H1N1 cases up to August 20, while Bengaluru has recorded notable clusters of influenza-like illness, including a school outbreak involving more than 500 students and 21 staff members. The Indian Council of Medical Research has said the circulating virus is not a new H1N1 strain.

Why flu may linger in Bengaluru

Dr Aishwarya R, Consultant in Infectious Diseases at Aster Whitefield Hospitals, said Bengaluru’s weather can favour respiratory viral infections for a longer period.

According to her, influenza activity that begins around June can continue through January and February, contributing to prolonged transmission. The report notes that seasonal patterns also depend on weather, population movement, crowding and virus circulation.

Watch for warning signs

Typical symptoms include dry cough, sore throat, fever, muscle and body aches and general weakness. Household transmission is also common, with another family member developing symptoms within days of the first case.

People with chronic lung conditions, asthma, heart, kidney or liver disease are more vulnerable to complications. Older adults, young children and pregnant women are also considered high-risk groups.

Persistent high fever, breathing difficulty, chest pain, confusion or increasing oxygen requirements should prompt urgent medical attention. Severe influenza can lead to pneumonia, low oxygen levels and acute respiratory distress syndrome.

Early treatment can make a difference

Doctors stress that antiviral treatment works best when started early in appropriate patients. Antibiotics such as azithromycin do not treat influenza because it is caused by a virus and should not be taken without medical advice.

Influenza vaccination can also reduce the risk of serious complications, including ICU admission and severe respiratory illness.

Rather than comparing Bengaluru and Delhi, doctors advise people to recognise symptoms early, protect vulnerable family members and seek medical care promptly when the illness worsens.