On swine flu surge, medical body ICMR’s advice on testing, end of the wave

Dr Rajiv Bahl, director-general of India's top medical research body, ICMR, has reassured the public that there is no need for widespread testing or vaccination against the seasonal flu, known as H1N1, also called swine flu. The mortality rate from this viral infection remains low, according to Bahl. He added that only those at high risk of severe disease, such as the elderly and those with compromised immune systems, should consider getting the flu shot after consulting their doctor.

Seasonal flu typically has two peaks in India: one in winter months (January to March) and another towards the end of the monsoon season. The current rise in H1N1 infections is part of this seasonal pattern, and no new strain of the virus has been identified, Bahl explained. He emphasized that people should not panic as the vast majority of infections are mild and self-limiting.

ICMR surveillance data shows that Influenza A (H1N1) pdm09 is currently the dominant respiratory virus among those presenting with cough and cold symptoms, accounting for around 97-98% of detected Influenza A infections. H3N2 accounts for about 2-3%, while Influenza B, particularly the Victoria lineage, is circulating but not predominant.

Dr Bahl explained that during the COVID-19 pandemic, testing was necessary because it was a new infection with a significant number of severe cases. However, this is not needed for seasonal flu, which is an endemic infection. The ICMR has a network of 73 viral laboratories in tertiary care hospitals across the country, which routinely collect and test samples from people with respiratory infections.

This surveillance system has been strengthened since the COVID-19 pandemic and currently shows a marked predominance of H1N1 among Influenza A viruses.