How Common Is Long COVID?

Just how many COVID-19 survivors have lingering health issues is an evolving target but appears to be a good many, a review found.

Self-reported symptoms of the disease persisted for 1 to 2 months after initial diagnosis in up to 13% of patients; 4.5% experienced symptoms beyond 2 months, and 2.6% for 3 months or longer, according to mobile app data from U.K., U.S., and Swedish populations.

However, many of these patients may not realize the hidden symptoms, noted David H. Jiang, of the Mayo Clinic in Rochester, Minnesota, whose group published the review in JACC: Basic to Translational Science.

In potentially more reliable clinic-based assessments, 33% to 98% of survivors have symptoms or complications for at least a month. The most common symptoms were:

• Fatigue (28.3%-98%)
• Headache (91.2%)
• Dyspnea (13.5%-88%)
• Cough (10%-13%)
• Chest pain (5%-42.7%)
• Anxiety or depression (14.6%-23%)
• Deficits in smell or taste (13.1%-67.5%)

However, symptoms can also include the cardiovascular, gastrointestinal, renal, endocrine, and musculoskeletal systems in both adult and pediatric populations, Jiang’s group noted.

“Additional complications are likely to emerge and be identified over time,” they wrote.

Their review covered 143 reports published through May 31 that described complications or symptoms that began or persisted more than 28 days after diagnosis of laboratory-confirmed COVID-19. These long-term consequences were together referred to as post-acute sequelae of severe acute respiratory syndrome coronavirus 2 infection (PASC) or colloquially as “long COVID” or “long haulers,” regardless of acute phase severity of symptoms.

Among the less common symptoms turned up in these reports were chest pain (up to 43%), palpitations/tachycardia (11.2%), concentration or memory deficits (23%), tinnitus or earache (3.6%), and sensory neuropathy (2.0%).

“Although data on PASC risk factors and vulnerable populations are scarce, evidence points to a disproportionate impact on racial/ethnic minorities, older patients, patients with preexisting conditions, and rural residents,” the review noted.

Now with the Delta variant dominating, Jiang told MedPage Today that he would add to that list.

“Most of the people who have contracted the Delta variant are unvaccinated populations,” he said. “I would now add unvaccinated status as a risk factor for long COVID.”

However, the comparative likelihood of PASC between Alpha and Delta variants hasn’t been well studied, like most aspects of long COVID, he pointed out. “The take home really is that we, number one, need more studies on long-term complications of COVID-19, PASC in general.”

On Wednesday, the NIH announced their plan to study long-term effects of COVID-19 by pulling together tens of thousands of patients in new and existing cohorts into a “meta-cohort” that will include adult, pregnant, and pediatric populations, known as the RECOVER Initiative.

“We know some people have had their lives completely upended by the major long-term effects of COVID-19,” said NIH Director Francis S. Collins, MD, PhD, in a press release. “These studies will aim to determine the cause and find much needed answers to prevent this often-debilitating condition and help those who suffer move toward recovery.”

“Given the range of symptoms that have been reported, intensive research using all available tools is necessary to understand what happens to stall recovery from this terrible virus. Importantly, the tissue pathology studies in RECOVER will enable in depth studies of the virus’s effects on all body systems,” added RECOVER co-chair Walter J. Koroshetz, MD, director of NIH’s National Institute of Neurological Disorders and Stroke.

Meanwhile for clinical practice, Jiang urged some level of checkups and appointments to screen COVID-19 survivors for persistent symptoms and complications “before they become worse.”