Omicron: Symptoms and treatment of the new strain of coronavirus

Omicron is the name of a new strain of the SARS-CoV-2 virus that causes coronavirus infection . Its appearance was caused by a mutation in the genome of the pathogen. Due to this, it acquired new properties that distinguish it from other varieties of coronavirus. Among them: a short incubation period, high contagiousness of omicron, the ability to elude the body’s immune response and cause an atypical course of the disease. In most cases, it is mild or asymptomatic, so many patients are sick at home, under the supervision of a local therapist .

However, this pathogen, like its predecessors, can also provoke the development of post-covid syndrome, in some cases complications arise that affect the normal functioning of the respiratory and cardiovascular systems.

The main difference of the viral particle of the omicron strain is in the structure of the spike protein. It is a structure responsible for the penetration of the infectious agent into the body’s cells. Antibodies are produced directly to this protein after an illness or vaccination , so the change in its structure makes SARS-CoV-2 more contagious and resistant to previously acquired immunity.

A fresh strain of coronavirus infection was registered by WHO on November 26, 2021. Scientists put forward several hypotheses about the reasons for the emergence of the omicron virus:

1. Infection of humans from animals. It is assumed that changes in the pathogen’s genome could have occurred in the body of sick rodents or other animals. Then the viral particles resumed circulation in the human population.
2. Virus mutations during long-term COVID-19 in HIV-infected people and people suffering from other types of immunodeficiency.
3. The coronavirus situation is in a bad state in a number of countries. If laboratories are not equipped with the necessary equipment to isolate and sequence the pathogen, new strains and gene mutations may emerge that escape the attention of scientists.
4. Low rates of herd immunity. In the bodies of people who have not been vaccinated, conditions are more favorable for prolonged circulation and mutations in virus particles. Weak vaccination organization in some countries, including South Africa, could have contributed to the emergence of a new strain of SARS-CoV-2.

Infection with the omicron strain of COVID-19 is possible through close contact with a person who coughs and sneezes and releases virus particles into the environment. This can also happen if you enter a room where a carrier of the infection has been for a long time. Pathogens enter the body through the respiratory tract, less often through the mucous membrane of the eye, bind to cell receptors and begin to multiply rapidly.

Due to mutations in the coronavirus genome, the omicron strain, unlike alpha, delta and gamma, is more contagious, can cause disease even in the presence of antibodies in people who have recovered and been vaccinated, is more severe in children, and has a tendency to affect the upper respiratory tract rather than the lungs.

The symptoms of the new strain of coronavirus omicron are similar to those of a cold. The disease is often mild, and often completely asymptomatic.

After 2-3 days or the next day from the moment of infection, the following symptoms of COVID-19 may be observed:

• impaired nasal breathing, sneezing;
• a feeling of irritation and pain in the throat;
• general weakness, fatigue, decreased performance;
• moderate headache,
• diarrhea;
• muscle pain;
• dry cough;
• nausea, vomiting;
• chills, fever;
• inflammation of the mucous membrane of the eye;
• rashes on the body;
• loss of taste and ability to smell.

The temperature during infection with omicron in most cases does not exceed 38 °C. In complicated cases, it can rise to higher values, difficulty breathing is added, coughing intensifies, a feeling of tightness and chest pain appears.

Unlike the symptoms caused by previous strains of coronavirus, infection with “omicron” in adult patients is accompanied by more pronounced weakness and body aches, throbbing headache, in some cases low body temperature values ​​are noted, and in children – skin rash.

The duration of the disease and manifestations depend on the state of the immune system, the treatment, and concomitant pathologies. In most cases, omicron symptoms persist for 5-10 days, if no complications develop.

The disease caused by the omicron strain, as in cases of infection with other variants of SARS-CoV-2, can be accompanied by increased thrombus formation followed by thrombosis of the veins of the lower extremities, pulmonary embolism, heart attack and stroke.

Post-COVID syndrome can develop within three months after recovery, even if the disease was mild or asymptomatic, and persist for up to eight months. It is associated with persistent inflammation, excessive activation of the immune system, neurological disorders. It is more pronounced in women who have been infected with omicron or other strains of coronavirus.

Symptoms of this condition include:

• weakness and fatigue;
• dyspnea;
• increase in body temperature to 37-37.5 °C;
• disruption of the digestive system;
• sleep disorder;
• anxiety;
• depression;
• decreased concentration.

Possible complications of the infection also include pneumonia, meningoencephalitis, autoimmune lesions of the peripheral nervous system, and hyperreaction of the immune system – cytokine storm. In children, infection with omicron can also lead to the development of bronchiolitis – an inflammatory process in the bronchioles, leading to their blockage.

There are no specific signs characteristic only of infection with the omicron strain. In a pandemic, at the first symptoms of acute respiratory infections, in order to clarify the diagnosis, experts advise performing PCR testing for COVID-19 or IHA – rapid testing for the COVID-19 antigen. To obtain reliable results, since the omicron strain coronavirus has a short incubation period and often occurs in a mild form, the study should be carried out already on the 3-4th day after the onset of initial signs of the disease.

According to indications, a study of immunoglobulins of class A, M, G SARS-CoV-2 is also carried out.

Non-specific laboratory diagnostics for infection with omicron is required for people with moderate, severe and extremely severe course of the disease. It involves:

• clinical blood test to determine the level of leukocytes ;
• biochemical blood test (ALT, AST, creatinine), determination of procalcitonin and inflammation markers (C-reactive protein, ferritin);
• assessment of blood clotting based on coagulogram and D-dimer data;
• determination of hormone levels in the blood .

To detect pathological changes in the lung tissue, a chest X-ray or CT scan of the lungs is performed . The latter is indicated only in the presence of symptoms of respiratory failure and low blood oxygenation.

Examination and management of patients is carried out by general practitioners, pediatricians , and, if necessary, infectious disease specialists , and intensive care unit doctors.

In the case of a mild course of COVID-19 caused by the omicron strain, treatment is aimed at increasing the body’s defenses, quickly eliminating the infection, alleviating symptoms, and preventing the development of complications. For this purpose, plenty of fluids, bed rest, regular ventilation of the room, and air humidification are recommended. Antipyretic drugs are used at temperatures above 38.0 °C, sprays, lozenges, and gargles are used to relieve a sore throat, and herbal infusions and expectorants are used for dry coughs. Alpha interferon preparations may be used.

In some cases, specific antiviral therapy (favipiravir, molnupiravir), anticoagulants, glucocorticosteroids, interleukin inhibitors and receptor antagonists, plasma and human antibodies from recovered or vaccinated people are prescribed on the doctor’s recommendation. Severely ill patients may require oxygen support or tracheal intubation for mechanical ventilation, parenteral administration of saline and colloidal solutions.

How long COVID-19 caused by omicron lasts depends on concomitant diseases, the state of the immune system, and the timeliness and correctness of the treatment. Since the disease is usually mild and complications are less common, the prognosis is usually favorable. However, the high contagiousness of the pathogen and, accordingly, the large number of patients seeking outpatient care can overload the healthcare system.

In this regard, prevention of omicron infection is so important. This includes the following measures:

• use of personal respiratory protective equipment – ​​masks and respirators;
• frequent hand washing and disinfection, use of gloves;
• maintaining social distance of 1.5-2 meters in crowded places.

Vaccination plays a special role in the fight against coronavirus. Scientists have confirmed the effectiveness of the drugs “Sputnik V” and “Sputnik Light” against the omicron strain. The risk of infection remains even after vaccination, but thanks to the vaccine, the virus can be blocked at the initial stage of penetration into the body, due to which the disease is more likely to proceed in a mild or asymptomatic form.