As the world grapples with the aftermath of coronavirus and cases of Omicron fall in most countries, a new study hints at concerning post-Covid complications. Researchers have said that people who were hospitalised with coronavirus should be routinely checked for flu as a study shows having the two more than doubles the risk of death.

In a study published in the medical journal Lancet, researchers have tried to understand the clinical outcome of respiratory viral co-infections with SARS-CoV-2. “SARS-CoV-2 co-infections with influenza viruses and adenoviruses were each significantly associated with increased odds of death,” the paper said.

Scientists also discovered that people who had contacted both coronavirus and the influenza viruses were 2.4 times at the risk of dying than if they just had Covid-19. The study hints that these patients are over four times more likely to require ventilation support post-hospitalisation to keep them breathing.

“We found that the combination of Covid-19 and flu viruses is particularly dangerous. We expect that Covid-19 will circulate with flu, increasing the chance of co-infections. That is why we should change our testing strategy for Covid-19 patients in hospital and test for flu much more widely,” Professor Kenneth Baillie of Edinburgh University told The Guardian.

The study was conducted among 2,12,466 adults with SARS-CoV-2 infection who were admitted to a hospital in the UK between February 6, 2020, and December 8, 2021. While viral co-infection was detected in 583 patients, 227 patients had influenza viruses, 220 patients had a respiratory syncytial virus, and 136 patients had adenoviruses.

SARS-CoV-2 co-infections with influenza viruses and adenoviruses were each significantly associated with increased odds of death.

Researchers said that it is the largest study of people with Covid-19 undergoing additional testing for endemic respiratory viruses, reporting 583 confirmed co-infections and 6382 confirmed SARS-CoV-2 mono infections. The study was conducted over a prolonged period of 18 months.

The team of researchers from Edinburgh University, Liverpool University, Imperial College London, and Leiden University in the Netherlands urged people to get vaccinated and booster shots in a bid to protect themselves from coronavirus. “The vaccines that protect against Covid-19 and flu are different, and people need both. “The way that these two infections are treated is also different, so it’s important to test for other viruses even when you have a diagnosis in someone who is hospitalised with a respiratory infection,” Professor Peter Openshaw of Imperial College London told Tha Guardian.

Meanwhile, scientists now believe that Covid-19 patients suffer more than respiratory issues. Several studies have revealed that the virus can also damage the heart. A September 2020 study found that the risk of a first heart attack increased by three to eight times in the first week after a Covid-19 infection was diagnosed.

The new study comes in the backdrop of a new surge being observed in some countries including China and South Korea.