With winter fast approaching, doctors are asking people to be extra cautious, as it is not yet clear to the medical fraternity how the coronavirus behaves in cold weather. Another concern is that since the symptoms of Covid-19 are also cough and fever, late diagnosis of cases may increase the fatality rate. Experts believe that a rise in pollution in winter could also contribute to Covid cases.
Seasonal infections are caused by the influenza virus and other members of the coronavirus family, which proliferate in winters. Researchers believe that Delhi is recording a sudden rise in Covid-19 cases because of the cold weather aggravated by air pollution.
“During winters, air pollutants are more static and come closer to the ground. As we know, SARS-Cov-2 spreads through mouth droplets. So, these infected droplets may remain suspended in the pollutants, which can be as small as PM2.5 and infect more people when they inhale it,” said Rajneesh Bhardwaj, a professor at the department of mechanical engineering, Indian Institute of Technology-Bombay, who has been studying how long the virus stays active on surfaces.
A recent study—'Air Pollution and Covid-19 Mortality in the United States: Strengths and Limitations of an Ecological Regression Analysis’ published by Harvard University shows that an increase of only one microgram per cubic metre in PM2.5 - dangerous tiny pollutants in the air - is associated with an 8 per cent increase in the Covid-19 death rate. “A small increase in long-term exposure to PM2.5 leads to a large increase in the COVID-19 death rate,” says the report, published last week.
Dr Jay Mullerpattan, Consultant, Respiratory Diseases, P D Hinduja Hospital & MRC, said people should continue to observe precautions such as wearing masks, physical distancing and handwashing hygiene even in winters. It will help in protection against other viruses as well. “Any neglect of symptoms and delay in testing could cause late diagnosis of Covid and may lead to complications. Colder temperatures and increase in pollution can cause worsening of respiratory ailments, which includes Covid-19 as well,” he said.
Along with outdoor air pollution, experts also caution about taking precautions to avoid indoor air pollution in winter. For instance, mosquito coils and incense can also contribute to infecting people in poor-ventilated rooms in winters, said Dr Sundeep Salvi, director of the Chest Research Foundation.
“There have been instances of a spike in most respiratory illnesses like SARS and influenza, among others, during winter, as viruses tend to survive longer in a cold and dry climate. Cold air is heavier and less mobile. This makes an easy path for the viruses to reach our lungs,” said Dr Salvi.
As a precautionary measure, the Brihanmumbai Municipal Corporation (BMC) has instructed the strengthening of fever clinics in all wards. “Considering that the symptoms of seasonal infection are similar to those of Covid-19, people have to be more cautious. They shouldn’t take medicines without a doctor’s prescriptions, as this could lead to late diagnosis,” said additional municipal commissioner
Dr Shashank Joshi, member of the state Covid-19 taskforce said, “When the pandemic started in March, it was speculated that the virus would wear off in summer, which didn’t happen. So far, we haven’t seen any correlation between the virus and the weather. As the virus is new, it is tough to say anything confirmatory.”