Scientists at Washington University have found that patients hospitalized with the flu can display long-term effects similar to those found in long COVID patients.
The researchers found evidence of long flu by looking at Veterans Administration hospital records of flu and COVID-19 patients that had been stripped of identifying information. In the year and a half after patients became sick with the flu, some suffered elevated risk of continued breathing and lung problems.
The study’s findings were published in December in the journal Lancet Infectious Diseases. Its authors said the results warn against playing down the seriousness of either virus.
“I think if there’s anything we learned from this pandemic, it’s that these infections are serious,” said Ziyad Al-Aly, a clinical epidemiologist at Washington University and one of the authors of the study. “It can put people in the hospital, it can actually result in death and result in long-term disease disability, and trivializing them is really silly.”
The rates of long-term problems were significant for both flu and COVID-19, the researchers found. But while lingering symptoms were present in some patients with the flu, they were much more likely to be found in patients who had been sick with COVID-19.
Additionally, while the flu mainly was associated with problems with pulmonary and respiratory systems, COVID-19 infection was correlated with problems in organs throughout the body, including gastrointestinal and cardiovascular systems, the study found.
Many have compared the coronavirus to the flu since the beginning of the pandemic, said Al Aly, also chief of research and development at the VA St. Louis Health System. Mostly, the comparison was used to play down the severity of the emerging virus.
“The public actually draws those parallels,” he said. “So we thought that, because it's really in the public consciousness and public narrative, it would be important to analyze that data scientifically and try to understand: Is, really, COVID worse than the flu?”
The VA data showed not only that the coronavirus was in many patients more serious than the flu, but that the flu also could also make people sick for months afterward.
“A bigger and better lens now being informed by this pandemic,” Al-Aly said. “And it tells us that these infections can have long-term consequences.”
As more patients became sick with long-term effects of the coronavirus, people became more aware of how viral infections can continue to ravage the body after patients heal from the acute phase of an illness, said Dr. Adnan Qureshi, a neurologist at the University of Missouri who has studied long COVID infection.
Qureshi, who was not involved in the study, said he was happy to see scientists backing up with data what patients have long intuited.
“If you ask people who have survived any infection, [they’ll say] things never went back to the same,” he said. “Many of them felt that they couldn't really even go back to the same jobs, or had to cut down their work hours, perhaps take less intellectually challenging jobs. But I think that it never got the same importance [as long COVID].”
The findings indicate a need for more awareness and treatment of long-term disabilities caused by viruses, he said.
Al-Aly said the findings are limited by the data, which only included those hospitalized with flu and coronavirus infections.
