Here’s how sickness, death compare between COVID-19 and the flu

Q: How different is COVID-19 compared to the flu?

A: Although influenza (the flu) and COVID-19 infections have some similarities, they are not the same. Both are contagious and caused by respiratory viruses, and both usually spread by close contact with an infected person.

Symptoms also are similar. People infected with either COVID-19 or the flu can present with fever, cough, trouble breathing, tiredness, sore throat, runny nose, muscle aches, headaches, vomiting, diarrhea and change in or loss of taste or smell.

However, the timing of symptoms and the duration of illness are different. People infected with the flu have symptoms one to four days after exposure, while symptoms for people infected with COVID-19 generally appear two to 14 days after exposure. While people with the flu are contagious for up to seven days, people with COVID-19 can be contagious for much longer. The difference in the window of time without symptoms is important, given that it is the period during which infected people are more likely to unknowingly spread the virus to others.

Although both can lead to serious complications such as pneumonia, respiratory failure, organ failure and death, the likelihood of serious complications is higher with COVID-19 than with the flu. Recent studies have reported significantly increased risk of serious complications from COVID-19 compared to the flu.

In a study published in the Centers for Disease Control and Prevention’s Mortality and Morbidity Weekly Report, hospitalized patients with COVID-19 had a more than five times higher risk for in-hospital death than did hospitalized patients with the flu. This risk was higher among Blacks and Hispanics compared to white patients.

Higher risk of respiratory complications across all age groups was also reported in a study published in The Lancet. The authors of that study reported that, although hospitalizations for children were lower for COVID-19 compared to the flu, the risk for death in children was higher in those admitted for COVID-19.

So far, more than 33 million people have had COVID-19 in the U.S., and more than 603,000 have died. By comparison, during the 2019-20 flu season in the U.S., 38 million people had the flu and about 22,000 died, a more than 25-fold difference between the two. Studies also suggest the risk of COVID-19 complications while also infected with the flu is increased. Risk of death doubles in people infected with both viruses.

Treatments for the two illnesses also differ. There are several anti-viral treatment options to treat the flu, but only one, remdesivir, approved anti-viral treatment option for COVID-19. Prevention is the best way to reduce the risk of both respiratory diseases. Both have effective vaccines that decrease the likelihood of serious infections, and both can be prevented with masking, social distancing and hand washing.

If having symptoms, testing should be considered to both diagnose and differentiate between the two. Given increasing cases of COVID-19 and the possibility of a winter surge, it is important to get vaccinated now for COVID-19 and also plan to get vaccinated for the flu in the fall.

Fernando Urrego, M.D., is the interim health officer at the Hamilton County Health Department and a member of the Chattanooga-Hamilton County Medical Society.