How common are post-acute sequelae of SARS-CoV-2 infection?

The 2019 pandemic of coronavirus infection (COVID-19) has had a profound impact on human lives, with more than two million injured to date. It is just as devastating to have been an economic tax. Now, a new study, released on the medRxiv* preprint server, describing the features and frequency of long drag signals in COVID-19.

COVID-19 long sequels

The percentage of patients suffering from prolonged symptoms, also known as post-acute sequelae of SARS-CoV-2 (PASC) infection, is unclear. The most common symptoms include extreme fatigue, shortness of breath (SOB), persistent anosmia and dysgeusia, and brain weakness. However, diagnostic criteria have not yet been developed, leading to frequency estimates ranging from 13% to 87%.

The first figure includes cases with symptoms lasting for four weeks or more from the time of diagnosis. The second comes from patients in the hospital who still have symptoms after 60 days from the onset of symptoms.

Other anonymities include the association between growing age, female gender, the severity of the disease, the presence of specific comorbidities, and PASC.

The current study aims to address population-based estimates of PASC in Michigan, given its demographic and clinical risk factors.

Study details

The study subjects were in the Michigan COVID-19 Rehabilitation Study Study (MI CReSS). All were tested with COVID-19 following a positive polymerase chain test (PCR). The scientists sampled about 600 subjects with disease starting on or before April 15, 2020, as determined by the onset of symptoms, advanced PCR, or referral to the health department.

More than half of the subjects were female, and nearly 70% were aged 45 years or older. Nearly half of whites were non-Hispanic, and just over a third were black.

Obesity was reported in over half, with 43% having high blood pressure, a quarter of diabetes, 17% asthma, and just over a tenth of cardiovascular disease.

About 40% were seriously ill, but over a quarter were seriously ill. About a third had moderate to severe disease; a third required hospitalization, and a tenth intensive care.

What were the results?

More than half (53%) and one-third (35%) of patients had symptoms at 30 and 60 days after onset, respectively. Elderly patients and those with more severe illness had a higher incidence of PASC, but even those aged 18–34 years had a higher incidence, at 35% and 20%, after 30 and 60 days, respectively.

Approximately one-third and one-quarter of patients with COVID-19 were also mild with PASC at 30 and 60 days, respectively. Among non-hospital patients, the figures were 44% and 27%, respectively.

Among those with persistent symptoms before 60 days after onset, more than half were tired, with 44% reporting SOB.

Risk factors for prolonged sluggish symptoms

In unchanged models, age, Hispanic ethnicity, and low annual income (less than $ 75,000 per year) appeared to be associated with higher incidence of PASC at 30 and 60 days. For example, subjects aged 55-64 years appeared to be twice as low as PASC at 60 days compared to those aged 18-34 years.

When adjusted for demographic factors, other illnesses and the severity of the illness, some of these risk factors lost their significance. However, those with a psychological illness were 42% higher at 60 days. In addition, those with a lower household income had a 40% higher risk at 30 days.

The most important risk factor was the severity of the illness. Those with very severe symptoms were 2.25 times more likely to have PASC at 30 days and 1.7 times more likely to have symptoms at 60 days, compared to those with mild symptoms.

Hospitalization increased risk by about 40% at 30 and 60 days. Among non-hospitalized patients, those with cardiovascular disease had a 54% higher incidence of PASC at 30 days, although this was not evident in the entire sample.

Among the non-hospital group, some significant differences in 60-day PASC risk factors were observed. For one, psychological illness was not a risk factor at this stage, but a history of obstructive pulmonary disease (COPD) increased the frequency of PASC. Moreover, signal depth was not an indicator for PASC risk at this stage.

What is the impact?

The study initiates frequency estimates among a geographically defined group, including all cases of COVID-19. The finding of a PASC frequency of 53% at 30 days reflects the numbers reported among Faroe Islands at 125 days after onset (in a non-hospital cohort).

However, the frequency at 60 days in the current study is much lower, at 35%, probably due to the difference in the study numbers.

The depth of the disease was a key predictor of PASC risk. Surprisingly, a quarter of those with moderate to severe illness had a high risk for these symptoms on day 60 after onset.

Symptomatic but non-hospital cases also have a high risk of PASC at both 30 and 60 days. The risk appears to be higher among black people mainly because they are at higher risk of COVID-19 in the first place and not because they develop a more serious disease. Higher levels of disease would lead to worse overall outcomes.

Increased disease severity due to higher viral load may drive PASC development. People from low-income situations tend to get higher doses of the virus, as they are more likely to be essential workers who cannot work from home, living in homes crowded, using public transport, and often do not have access to suitable personal protective equipment. This may explain why these people are at increased risk of PASC.

With more and more illnesses developing, the patient is more likely to suffer from maltreatment and severe inflammation. This prolongs the recovery period and damages various tissues and organs. The association between the viral load, the immune response, the severity of disease and the risk of PASC needs to be examined in more detail.

COVID-19 still affects millions every day. “While we are still trying to control the spread of COVID-19 and treat serious illness, we cannot delay developing strong efforts to identify and treat PASC, which could affect millions of COVID-19 survivors worldwide.. ”

* Important message

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be seen as final, guiding health-related clinical practice / behavior, or treated as fixed information.