Around seven months in, flu shows no signs of leaving city

Chennai: Doctors who have been seeing patients with symptoms of flu and respiratory diseases for more than seven months since Aug 2024 are now wondering if the flu is endemic. While influenza continues to be the most dominant illness, doctors are seeing a surge in viral respiratory infections.

A combination of reasons, including increased political, religious and entertainment congregations, travel, weather conditions and increased testing, are suspected to have triggered the surge. Yet, by now, the cases should have come down. "We still see patients coming to the hospital with fever, cough and cold," said Dr Subramanian Swaminathan, who works at Gleneagles Healthcity.

Most doctors said it is important to study the new flu pattern. "Unlike countries like the US or Australia, flu is not seasonal in India. In the US, the flu season starts in Oct when winter begins, while in Australia, it starts around May. In India, we have outbreaks in different parts throughout the year. It starts at the onset of the monsoon in June-July in Kerala, but from Oct to Nov in Chennai. There may be peaks or outbreaks at different times of the year. This year, however, we are seeing a steady number since Aug," said infectious diseases expert Dr V Ramasubramanian.

The state public health laboratory, which has been screening samples at random, said 60per cent of fever cases returned positive for the influenza virus. "Most patients have influenza A — particularly subtypes H1N1 and the seasonal flu, H3N2. Besides these, we see a cocktail of viruses such as the RSV and adenovirus," said S Raju, who heads the state public health laboratory.

While most people recover from symptoms in less than a week, some are left with a persistent cough and body pain. Elderly patients with comorbid conditions can have complications. "The flu virus spreads through respiratory droplets when an infected person coughs, sneezes, or talks. When these droplets are inhaled, it can cause infection. A mask can reduce the chances of infection," said director of public health Dr T S Selvavinayagam.

Most hospitals say there is an increase in demand for testing in the past three months. Hospitals charge around 2,000 to screen for influenza, Covid, or respiratory syncytial virus infection in a person with severe symptoms of flu. "We are also seeing more cases now also because we are testing more," he said.