What is a “long-distance” COVID? How is it related to the widespread symptoms of other viruses?

As of July 8, 2021, approximately 186 million people were infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), and more than 4 million died from this virus. .. About 80% of individuals who develop coronavirus disease 2019 (COVID-19), a disease caused by SARS-CoV-2, experience mild to moderate symptoms, while about 5% develop severe symptoms. To do.

As more research is being done on people who have recovered from COVID-19, the onset of persistent or new symptoms that last for weeks or months is becoming more and more common. This phenomenon is called “long COVID” or “post-COVID syndrome”.

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Acute COVID-19

After infection with SARS-CoV-2, symptoms often begin to develop 4-5 days after initial exposure. Acute symptoms associated with COVID-19 can be divided into three categories, including respiratory, musculoskeletal, and bowel symptoms.

Respiratory Symptoms of COVID-19 You may have a cough, sputum, shortness of breath, or fever. Similarly, COVID-19 musculoskeletal symptoms include muscle aches, joint pains, headaches, and malaise. Third, the symptom clusters associated with this disease include: stomach ache, Vomiting, and diarrhea. Apart from the above symptoms, more serious symptoms that can occur during acute COVID-19 include chest pain, confusion, and shortness of breath.

Long COVID-19

Recovery from mild COVID-19 usually occurs 7 to 10 days after the onset of symptoms. However, patients who experience a more severe form of this infection may find that their symptoms do not improve until 3 to 6 weeks after the onset of the symptoms. Ongoing follow-up of patients who recovered from COVID-19 found that one or more symptoms appeared to persist for weeks to months in a significant proportion of these patients.

Often used to explain the persistence of these various symptoms, “long COVID” can be essentially continuous or recurrent and in remission. In particular, microbiological recovery in these patients has been confirmed to be negative by the polymerase chain reaction (PCR) test, which returned to negative. Therefore, long COVID is the time lag between this microbiological recovery and the clinical recovery of symptoms.

Symptoms

Interestingly, long COVID-19 may be associated with the persistence of one or more symptoms experienced while the patient was infected with COVID-19. It may also be associated with the development of entirely new symptoms. Two major patterns of symptoms are usually associated with long COVID and can be divided into two categories: general malaise and upper respiratory tract complaints or multiple system complaints.

The first category of long COVID symptoms includes fatigue, headache, shortness of breath, sore throat, persistent cough, and loss of odor. In particular, severe malaise is a common symptom of long COVID, with some studies showing that it affects more than 50% of patients who recover from COVID-19. By comparison, multi-system complaints can range from ongoing fever to gastrointestinal symptoms such as nausea, vomiting, and diarrhea.

Pathophysiology

Several different mechanisms have been proposed that cause long COVIDs, some of which include:

• Persistence of chronic inflammation
• Immune response
• Persistence of the virus in the body
• Non-specific effects of hospitalization
• Sequelae of serious illness
• Post-intensive care syndrome
• Complications associated with comorbidities
• Side effects of the drug
• Persistent viremia in immunocompromised patients
• Reinfection / recurrence
• Psychological problems

Other viruses associated with persistent symptoms

Post-viral fatigue, one of the most commonly reported complaints associated with long-term COVID-19, has been reported in patients who have recovered from many other viral infections. More specifically, this persistent symptom appears after recovery from Ebola virus, the 2002 epidemic of severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and Epstein-Barr virus (EBV). It has been reported.

In fact, it is estimated that up to 40% of patients who recover from SARS, a virus that shows some similarities to SARS-CoV-2, have chronic fatigue. Some of the various mechanisms that have been proposed to be responsible for persistent muscle fatigue after recovery from these viruses are the presence of chronic oxidative and nitrosated stress, mild inflammation, and heat shock proteins. Includes impaired production of (HSP).

Long-distance symptoms of Ebola, in particular, are often compared to symptoms associated with long COVID-19. In addition to prolonged fatigue, survivors of Ebola also report some neurological symptoms such as pain, headaches and dizziness.

Further studies of the persistence of these symptoms show that the majority of survivors of Ebola experience a resurgence of antibody levels similar to those present during virus infection for up to 12 months after recovery. I did. Ebola virus genetic material has been detected in the eyes, lymph nodes, breast milk, and semen for several months after recovery.

Conclusion

Overall, scientists believe that the symptoms of both long COVID and long Ebola are due to the body’s inability to eliminate the virus. These viruses can continue to cause local inflammation by staying in various reservoirs. As the virus propagates in these areas, it periodically returns to the bloodstream, where it can cause a more macroscopic immune response and associated symptoms.

Apart from this hypothesis, scientists also suggest that SARS-CoV-2 may even provoke an autoimmune response in some patients. This proposed mechanism also depends on gender. More specifically, women who are already predisposed to autoimmune disease have been reported to be more likely to be affected by long-term COVID. To identify possible autoimmune mechanisms for COVID-19, researchers are currently trying to identify circulating patients. Autoantibodies To identify if these antibodies are causing these long symptoms.

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