Long COVID March 2023

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Last reviewed
March 14, 2023
Content Overview
Long COVID diagnosis in 2023 includes a variety of symptoms related to various health conditions.

Long COVID March 2023

According to the U.S. Centers for Disease Control and Prevention (CDC), the disease Post-Acute Sequelae of COVID-19 (PASC2) is known as long COVID. In April 2022, the U.S. National Research Action Plan on Long COVID introduced a government-wide national research agenda. The CDC's working definition of post-COVID conditions was developed by the Department of Health and Human Services (HHS) in collaboration with CDC and other partners.

The February 2023 Vital Statistics report addendum (COVID-19 Alert No. 10), initially published in April 2020, now authorizes post-acute sequelae of COVID-19 (PASC) to be listed as a cause of death on death certificates.

Long COVID Research 2023

On March 6, 2023, a preprint published by The Lancet reported Metformin use significantly reduced long COVID cases compared to the placebo; 63% reduced risk if taken within 4 days of symptoms.

Data published in the U.K. on February 23, 2023, indicates the risk of long COVID (~4%) decreases after a second COVID-19 infection compared to the first infection (~2.4%).

An Original Investigation published in JAMA Internal Medicine on February 2023 found an association between five lifestyle factors (healthy body weight and adequate sleep) and a 50% lower risk of long Covid compared to participants with none of those factors. 

A Kaiser Family Foundation analysis of the Household Pulse Survey found on January 26, 2022, that the percentage of respondents who have had COVID-19 during the pandemic and are reporting long COVID symptoms declined from 19% in June 2022 to 11% in January 2023.

A nationwide cohort study published by the BMJ on  January 11, 2023 - Long covid outcomes at one year after mild SARS-CoV-2 infection: suggests that patients with mild covid-19 are at risk for a small number of health outcomes, most of which are resolved within a year from diagnosis. This analysis assessed a very large variety of symptoms reported during the long covid period.

The peer-review journal Nature Medicines published the findings from a new study on December 8, 2022, that presents a large-scale transcriptome-wide investigation of blood gene expression changes occurring during acute COVID-19 that are associated with subsequent PASC. 

On December 7, 2022, an Original Article posted by JIM: Post COVID-19 condition diagnosis: A population-based cohort study of occurrence, associated factors, and healthcare use by the severity of acute infection, concluded the differential association of age, sex, comorbidities, and healthcare use with the severity of the acute infection indicates different trajectories and phenotypes of post-COVID-19 condition, with incomplete resolution 1 year after infection.

The JAMA Network published an Original Investigation on October 10, 2022, that presents modeled estimates of the proportion of individuals with at least 1 of the 3 self-reported Long COVID symptom clusters (6.2%, including 3.7% for ongoing respiratory problems, 3.2% for persistent fatigue with bodily pain or mood swings, and 2.2% for cognitive problems after adjusting for health status before COVID-19) three months after symptomatic SARS-CoV-2 infection.

And a study published in The Lancet in July 2022 found that 22% of people with long Covid were unable to work due to ill health, and another 45% had to reduce hours worked. 

This NIH study found an increased risk of long COVID in female participants and participants with a pre-COVID-19 history of anxiety disorder. However, long COVID can happen to anyone, even if their illness is mild.

 A non-peer-reviewed study published by Harvard researchers in June 2022 reports the discovery of a SARS-CoV-2 spike protein circulating in about half of long Covid patients up to one year after being diagnosed with an active infection.

According to a large study published in the International Journal of Infectious Diseases on September 30, 2022, older people were the most likely to report symptoms and have abnormal chest imaging and lung function tests. The most common long COVID symptoms among older adults are fatigue and dyspnea.

A study published in the Journal of Clinical Medicine in April 2022 concluded, 'We did not observe an increased incidence of pericarditis nor myocarditis in adults recovering from COVID-19 infection. Post-COVID-19 infection was not associated with either myocarditis (aHR 1.08; 95% CI 0.45 to 2.56) or pericarditis (aHR 0.53; 95% CI 0.25 to 1.13).

The journal Nature Medicine published a study on Feb. 7, 2022, offering evidence that the 1-year burden of cardiovascular disease in survivors of acute COVID-19 is substantial.

The study published by The Lancet on Mar. 21, 2022, found that even mild infection increased the risk of new-onset type 2 diabetes, although the risk increased with the severity of COVID-19 symptoms.

Led by the University of Innsbruck researchers, an Original Article was published in Radiology on Mar. 29, 2022, that found among 91 COVID-19 pneumonia survivors in Austria, 54% had lung abnormalities identified on computed tomography (CT) imaging one year after symptom onset. And 31/49 (63%) participants with CT abnormalities did not show further improvement after six months.

On June 9, 2022, the journal Nature published - Researchers are learning more about how the SARS-CoV-2 coronavirus stifles smell — and how they might revive it. A study found that people who had contracted the Alpha variant — the first variant of concern to arise — were 50% as likely to have chemosensory disruption compared with those infected with the original virus. This probability fell to 44% for the later Delta variant and 17% for Omicron's latest variant.

A study published by the JAMA Network on April 11, 2022, found that COVID-19 infection is associated with axon injuries and microvasculopathy in olfactory tissue. In some cases, the striking axonal pathology indicates that olfactory dysfunction in COVID-19 infection may be severe and permanent.

A study published on April 28, 2022, reported the Phenome-wide association studies (PheWAS) of genetic variants were associated with severe COVID-19 and demonstrated shared genetic architecture between COVID-19 severity and known underlying risk factors for both severe COVID-19 and poor COVID-19 outcomes, rather than susceptibility to other viral infections. And on January 4, 2022, a study published by JAMA stated, 'PheWAS have shown that specific genetic variations may be associated with multiple conditions and traits.'

September 22, 2022 - Study published by the journal Nature Medicine: Long-term neurologic outcomes of COVID-19.

August 25, 2022 - The Lancet published: Persistence, prevalence, and polymorphism of sequelae after COVID-19 in unvaccinated, young adults of the Swiss Armed Forces: a longitudinal, cohort study. Interpretation: Young, previously healthy individuals largely recover from SARS-CoV-2 infection. However, the constellation of higher BMI, dyslipidemia, and lower physical endurance 180 days after COVID-19 is suggestive of a higher risk of developing metabolic disorders and possible cardiovascular complications.

August 10, 2022 - A non-peer-reviewed study - Distinguishing features of Long COVID identified through immune profiling - Analysis of circulating immune mediators and various hormones also revealed pronounced differences, with levels of cortisol being uniformly lower among participants with Long COVID relative to matched control groups. Integration of immune phenotyping data into unbiased machine learning models identified significant distinguishing features critical in the accurate classification of Long COVID, with decreased levels of cortisol being the most significant individual predictor. 

August 9, 2022 - The journal Nature published: Long-COVID treatments: why the world is still waiting.

July 25, 2022 - The journal Nature Medicine published a study: Symptoms and risk factors for long COVID in non-hospitalized adults. Among the cohort of patients infected with SARS-CoV-2, risk factors for long COVID included female sex, belonging to an ethnic minority, socioeconomic deprivation, smoking, obesity, and a wide range of comorbidities. The risk of developing long COVID was also found to be increased along a gradient of decreasing age. 

May 25, 2022 - The peer-review journal Nature Medicine published: Long COVID after breakthrough SARS-CoV-2 infection. The findings suggest that vaccination before infection confers only partial protection in the post-acute phase of the disease; hence, reliance on it as a sole mitigation strategy may not optimally reduce the long-term health consequences of SARS-CoV-2 infection.

May 24, 2022 - The U.S. CDC published: Post–COVID Conditions Among Adult COVID-19 Survivors. COVID-19 survivors have twice the risk for developing pulmonary embolism or respiratory conditions; 20% of COVID-19 survivors aged 18–64 years and 25% of survivors aged ≥65 years experienced at least one incident condition that might be attributable to the previous COVID-19.

May 24, 2022 - Original Research: A Longitudinal Study of COVID-19 Sequelae and Immunity: Baseline Findings - conclusion: A high burden of persistent symptoms was observed in persons after COVID-19. An extensive diagnostic evaluation revealed no specific cause of reported symptoms in most cases. Antibody levels were highly variable after COVID-19.

May 21, 2022 - University of Milan researchers reported that about half of the study participants had thyroid abnormalities a year after COVID-19.

May 12, 2022 - Frontiers in Medicine published: The Impact of Initial COVID-19 Episode Inflammation Among Adults on Mortality Within 12 Months Post-hospital Discharge. Although suggestive, treatment with anti-inflammatory medications like steroids upon hospital discharge is associated with a decreased post-acute COVID-19 mortality risk.

May 11, 2022 - The Lancet published: Health outcomes in people two years after surviving hospitalization with COVID-19: a longitudinal cohort study. Interpretation: Regardless of initial disease severity, COVID-19 survivors had longitudinal improvements in physical and mental health, with most returning to their original work within two years; however, the burden of symptomatic sequelae remained relatively high. COVID-19 survivors had a remarkably lower health status than the general population at two years. 

April 25, 2022 - "Our findings reveal different associations between age, sex, comorbidities, symptoms, and healthcare use in people with more severe and milder forms of Long COVID disease, which indicates different clinical trajectories and characteristics of long COVID," commented Pontus Hedberg, MD. The study also found a strong association between a history of outpatient primary care visits and long COVID-19 in those with initially mild COVID-19 but not those treated in hospitals or the ICU. In addition, the researchers found the rate of outpatient care visits in people with long COVID-19 was substantially higher in the 10-12 months after the initial infection.

April 25, 2022 - About 60% of COVID-19 patients still have a least one symptom a year later. A long Covid study reveals that fatigue, shortness of breath, and irritability are the most common lasting symptoms.

April 22, 2022 - Researchers from the University of California - Los Angeles Health Sciences published: Reduced Cell Surface Levels of C-C Chemokine Receptor 5 and Immunosuppression in Long Coronavirus Disease 2019 Syndrome. In an exploratory trial treating "long COVID" with the CCR5-binding antibody leronlimab, we observed significantly increased blood cell surface CCR5 in treated symptomatic responders but not in nonresponders or placebo-treated participants. These findings suggest an unexpected mechanism of abnormal immune downmodulation in some persons normalized by leronlimab.

April 21, 2022 - Researchers in the UK reported that the average Long COVID infection lasted approximately 73 days, with the longest known COVID-19 infection lasting 505 days. 

April 5, 2022 - Nature Communications published: Course of post-COVID-19 disease symptoms over time in the ComPaRe long COVID prospective e-cohort. Among patients symptomatic after two months, 85% still reported symptoms one year after their symptom onset. Evolution of symptoms showed a decreasing prevalence over time for 27/53 symptoms (loss of taste/smell), a stable prevalence over time for 18/53 symptoms (dyspnoea), and an increasing prevalence over time for 8/53 symptoms (paraesthesia). The disease's impact on patients' lives began increasing six months after onset.

April 5, 2022 - MedpageToday reported a small study showed people with persistent cognitive changes after mild COVID had elevated levels of immune activation and immunovascular markers in their cerebrospinal fluid ten months after an acute SARS-CoV-2 infection. "If true, these findings imply that inflammation within the brain may contribute to these cognitive changes after COVID, and SARS-CoV-2 could trigger an immunovascular dysregulation via endothelial dysfunction and activation."

April 4, 2022 - Open Forum Infectious Diseases published a study: Rheumatic symptoms following COVID-19: a chronic post-COVID-19 condition. Conclusions - Our investigation showed a considerable proportion of rheumatic symptoms following COVID-19 in discharged patients, highlighting the need for continuing attention. Notably, rheumatic symptoms following COVID-19 were independent of the severity of the illness and corticosteroid treatment during the acute phase.

Mar. 29, 2022 - A research letter published in the International Journal of Infectious Diseases shows that nine months after COVID-19 diagnosis, 30% of patients have an impaired sense of taste, but complete loss of taste was uncommon. A likely explanation is that the damage to the olfactory/ gustatory epithelium varies between cases.

Mar. 17, 2022 - Researchers at the University of Cambridge recently found that about 70% of COVID-19 patients struggle with neurological, memory, and concentration problems in the months after infections.

Mar. 1, 2022 - The journal Neurology published a CLINICAL/SCIENTIFIC NOTE: Peripheral Neuropathy Evaluations of Patients With Prolonged Long COVID - This report strengthens the evidence linking several idiopathic multisymptom conditions—including SFN and fibromyalgia—with dysimmunity, sometimes incident to infections or vaccinations. However, as with COVID-incident Guillain-Barré syndrome and all referral-based case series, the current cases neither confirm causality nor any association's clinical significance or magnitude. 

Feb. 11, 2022 - UC Davis published an article: 11 things doctors have learned about long COVID.

Feb. 9, 2022 - The BMJ published research: A retrospective cohort study is the risk of persistent and new clinical sequelae among people 65+ years during the post-acute phase of SARS-CoV-2 infection. Conclusions: The results confirm an excess risk for ongoing and further sequelae in seniors after acute infection with SARS-CoV-2. 

Jan. 22, 2022 - The peer-reviewed journal The Lancet published a Correspondence: Long COVID and self-management.

Note: This information has been fact-checked by healthcare professionals.