People hospitalized with flu are at greater risk of long-term health problems, similar to those with prolonged Covid, data suggests.
Although the symptoms associated with such “long flu” are more focused on the lungs than ongoing Covid symptoms, in both cases the risk of death and disability was greater in the months after infection than in the first 30 days.
“It is very clear that long flu is worse than the flu, and long Covid is worse than Covid,” said Dr. Ziyad Al-Alya clinical epidemiologist at Washington University in St. Louis, Missouri, who led the research.
He was motivated to study the phenomenon after observing the extent of long-term illnesses experienced by people who have recovered from Covid.
“Five years ago, it would not have occurred to me to investigate the possibility of a ‘long flu’. But one of the most important lessons we have learned from this pandemic is that a virus that we all initially thought could only cause acute illness is leaving millions of people with prolonged Covid, he said. “We wondered if it could happen to other things. Can it happen with the flu, for example?”
To investigate, Al-Aly and colleagues analyzed medical records of 81,280 US patients hospitalized with Covid and 10,985 hospitalized with seasonal flu, and followed them for at least 18 months to find out about their risks of death, hospital readmission and 94 different health conditions problems involving the body’s major organ systems.
The research, published in the Lancet Infectious Diseasesfound that while Covid patients faced an increased risk of death or hospital readmission in the next 18 months, both infections carried a significant risk of continued disability and illness.
In both cases, more than half of the deaths and disability occurred in the months after infection, as opposed to the first 30 days. And although the symptoms associated with prolonged flu were more likely to focus on the lungs – for example, shortness of breath or a cough – compared to Covid patients, both groups have a greater risk of fatigue, cardiovascular, gastrointestinal and associated neurological problems and symptoms. with other organ systems in the following months.
“Many people think they have Covid-19 or the flu after being discharged from hospital. This may be true for some people. But our research shows that both viruses can cause long-term illnesses,” Al-Aly said. “Conceptualizing these diseases as acute diseases is really only looking at the tip of the iceberg, and obscures the much higher toll of adverse health outcomes that occur in the post-acute phase.
“Some people end up with serious long-term health issues. We need to wake up to this reality and stop trivializing viral infections and understand that they are the main drivers of chronic disease.”
The study was not designed to identify what proportion of those hospitalized with flu go on to develop further health problems, or whether certain groups are at greater risk, something the team hope to find in the to investigate in the coming months. Also unclear is the extent to which people who get the flu but are not hospitalized develop ongoing health issues.
For now, Al-Aly said the most important thing is to reduce the risk of being hospitalized for these diseases, through vaccination and, in the case of Covid, antiviral drugs.
