Long-term COVID was caused by mild cases of COVID-19 in most people

The Research summary is a short presentation of an interesting academic work.

Great idea

Even mild cases of COVID-19 can have major and long-term consequences for people’s health. This is one of our key findings a recent multi-country study on long-term COVID-19—or long-term COVID—was recently published in the Journal of the American Medical Association.

A long COVID is defined as the continuation or development of symptoms three months after the initial infection with SARS-CoV-2, the virus that causes COVID-19. These symptoms persist for at least two months after onset without any other explanation.

We found that an astounding 90 percent of people living with COVID for a long time had only mild illness with COVID-19 to begin with. However, after long-term development of COVID, the typical person experienced symptoms including fatigue, shortness of breath, and cognitive problems such as brain fog—or a combination thereof—that affected daily functioning. These symptoms had an equally serious impact on health long-term effects of traumatic brain injury. Our study also found that women have twice the risk of men and four times the risk of children for developing long-term COVID.

We analyzed data from 54 studies of more than 1 million people from 22 countries who experienced symptoms of COVID-19. We counted how many people with COVID-19 developed clusters of new long-term symptoms of COVID and determined how their risk of developing the disease varied by their age, gender, and whether they had been hospitalized for COVID-19.

We found that patients who were hospitalized for COVID-19 had a higher risk of developing long-term COVID—and longer-lasting symptoms—compared to people who were not hospitalized. However, since the vast majority of COVID-19 cases do not require hospitalization, many more cases of long-term COVID arise from these milder cases despite the lower risk. Among all people with long-term COVID, our study found that almost one in seven still had these symptoms a year later, and researchers do not yet know how many of these cases may become chronic.

Why it matters

Compared to COVID-19, Relatively little is known about long-term COVID.

Our systematic analysis of this situation in multiple countries has yielded findings that illuminate the potentially large human and economic costs of long-term COVID worldwide. Many people living with the condition are able-bodied adults. Inability to work for several months can cause loss of income, livelihood and housing. For parents or caregivers with long-term illness from COVID, the condition can leave them unable to care for their loved ones.

Based on the ubiquity and severity of long-term COVID, we think it is preventing people from working and therefore contributing to labor shortages. A long COVID could also be a factor in how people lose their jobs it disproportionately affected women.

We believe that finding effective and affordable treatments for people living long-term with COVID should be a priority for researchers and research funders. Long clinics for COVID-19 have been opened provide specialized carebut the treatments they offer are limited, inconsistent and it can be expensive.

What’s next

Long-term COVID is a complex and dynamic condition – some symptoms disappear, then return and new symptoms appear. But researchers don’t yet know why.

While our study focused on the three most common symptoms associated with long-term COVID that affect daily functioning, the condition can also include symptoms such as loss of smell and taste, insomnia, gastrointestinal problems, and headaches, among others. But in most cases these additional symptoms appear together with the main symptoms for which we have made assessments.

There are many unanswered questions about what predisposes people to long-term illness from COVID-19. For example, how else risk factors, including smoking and high body mass index, affect the likelihood of developing this condition in humans? Does he get infected again with SARS-CoV-2 change the risk for long COVID? Also, it is not clear how protection against long-term COVID changes with time after a person is vaccinated or enhanced against COVID-19.

The variants of COVID-19 also present new puzzles. Researchers know this omicron variant is less lethal than previous strains. Initial evidence suggests lower risk of long-term COVID of omicrons compared to earlier strains, but much more data is needed.

Most of the people we studied were infected more deadly variants which circulated before the omicron became dominant. We will continue to build on our long-term COVID research as part of Global burden of disease study—which estimates mortality and disability from all diseases and injuries in every country in the world—to get a clearer picture of how the long-term balance of COVID-19 has changed since the micron arrived.

Sarah Wulf Hanson is the leading researcher of Global Health Metrics, University of Washington and Theo Vos is a professor of health metric sciences, University of Washington

This article was republished from Conversation under Creative Commons license. Read Original article.