Multiple congenital anomalies
[19][30][31][32][19,30,31,32].
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Clinicians also include age (up to 1 year and 10–14 years) and non-European races as risk factors
[30].
In pediatric practice, there are three stages of COVID-19 that characterize clinical manifestations at different periods of time after infection. At the first stage of the disease, which lasts for 3–7 days, the virus replicates. The SARS-CoV-2 virus can initiate a pathological response of the immune system, which in some patients reaches the level of a cytokine storm. Inadequate responses of the immune system lead to pathological activation of the hemostasis system. This is the second stage of COVID-19, which lasts about 7 days. The third stage of COVID-19 occurs approximately 14–15 days after the onset of the disease. This stage is characterized either by the patient’s recovery with a favorable course of the disease or by the development of complications with an unfavorable course
[16].
It is worth noting that some children who have undergone a new coronavirus infection, COVID-19, may develop multisystem inflammatory syndrome (MIS-C). This syndrome is also called pediatric multisystem inflammatory syndrome and is temporarily associated with SARS-CoV-2. The syndrome was first described in healthy children with severe inflammation and signs of Kawasaki disease who were identified as having had a current or recent SARS-CoV-2 infection
[31]. MIS-C corresponds to the postinfectious inflammatory syndrome associated with SARS-CoV-2. Most patients with MIS-C have serological signs of previous SARS-CoV-2 infection, but only some patients showed a positive result for SARS-CoV-2 upon admission
[33][34][35][36][33,34,35,36].
The peak of the population incidence of MIS-C is about 4 weeks behind the peak of acute pediatric hospitalizations associated with COVID-19
[32][37][38][32,37,38]. MIS-C is caused by metabolic disorders in conditions of prolonged persistence of the virus in the body.
MIS-C is manifested by fever (>38.0 °C for ≥24 h), laboratory signs of inflammation (more than one violation in the following indicators: increased levels of C-reactive protein, fibrinogen, procalcitonin, D-dimer, ferritin, lactate dehydrogenase, or interleukin (IL)-6; increased erythrocyte sedimentation rate or the number of neutrophils; or decrease in the number of lymphocytes or albumin level) and clinical signs of a serious disease requiring hospitalization, with multisystem (i.e., >2) organ damage (heart, kidneys, respiratory organs, blood changes, gastrointestinal tract, skin, central nervous system)
[32][39][32,39].
Patients with MIS-C are often in critical condition, and up to 80% of children need hospitalization in the ICU. The registered mortality rate in the USA for hospitalized children with MSW ranges from 1% to 2%. Currently, studies are continuing to study the long-term consequences of this syndrome
[39][40][39,40].
The literature also describes such a course of SARS-CoV-2 infection in children as prolonged COVID-19. Italian scientists equate it with MIS-C; however, these conditions presumably have different etiologies. Studies concerning this manifestation are quite heterogeneous; they depend on the level of childhood morbidity in the country and on the symptoms described by parents. In official international sources, the protracted COVID-19 is not described, but there is such a thing as post-COVID. Long-term COVID includes both post-acute COVID-19 and post-ovoid syndrome. According to an international study, the duration of prolonged COVID with the preservation of some symptoms is possible up to 6–7 months
[41][42][41,42].
A review of clinical practice in the field of the problem under study gives grounds to conclude that the severity of the patient’s condition is determined by the severity of clinical symptoms. To date, it has been established that a severe course is observed on average in 1% of cases. More than 95% of all cases of the disease vary from an asymptomatic course to clinical manifestations of mild and moderate severity
[17][17][22][32][17,17,22,32].
WHO identifies three forms of the disease (mild, severe, and critical)
[32]. The critical form of COVID-19 is determined by the criteria of acute respiratory distress syndrome (ARDS), sepsis, septic shock, or other conditions that usually require life-sustaining therapy, such as artificial ventilation (invasive or non-invasive) or vasopressor therapy. Indicators of the severe form of COVID-19 are:
- -
-
Oxygen saturation < 90% in room air;
-
- -
-
Signs of pneumonia;
-
- -
-
Signs of severe respiratory failure (very strong chest retraction, grunting, central cyanosis, or the presence of any other common dangerous sign, including inability to breastfeed or drink, lethargy, convulsions, or a decrease in consciousness)
[43][44][45][46][47][48][49][50][51][52][43,44,45,46,47,48,49,50,51,52].
-
The non-severe form of COVID-19 is identified as the absence of any criteria for the severe or critical course of COVID-19.
In Russia, they focus on five working criteria for the severity of the COVID-19 course (asymptomatic course, mild course, moderate course, severe course, and critical course)
[31][53][31,53].
The critical form of COVID-19 (extremely severe course) is determined by the occurrence of acute respiratory distress syndrome (ARDS), multisystem inflammatory syndrome (develops against the background of COVID-19 or after 3–4 weeks), hypercoagulation, DIC syndrome, and hemophagocytic syndrome (HFS).
Severe form of COVID-19 ARVI (fever, cough) at the beginning of the disease, which may be accompanied by symptoms from the gastrointestinal tract (diarrhea). The disease usually progresses within 7 days; there are signs of respiratory failure (shortness of breath with central cyanosis) and oxygen saturation of the blood <93%. On the X-ray and computed tomography (CT) of the chest organs, there are signs of lung damage typical of severe or critical viral interstitial lung damage (CT3-4).
The moderate form differs from the severe one by the absence of obvious signs of respiratory insufficiency (shortness of breath) and hypoxemia; blood oxygen saturation is >93%. A chest CT shows minor changes in the lungs, typical of mild or moderate viral lung damage (CT1-2). Also, the symptoms of a moderate form of the severity of the disease are fever >38.0 °C and cough (mainly dry, unproductive).
With a mild form of COVID-19 and an increase in body temperature of less than 38.0 °C, symptoms of intoxication (weakness, myalgia) and damage to the upper respiratory tract (cough, sore throat, nasal congestion) are usually observed. During examination, changes in the oropharynx are noted; there are no auscultative changes in the lungs. In some cases, there may be no fever, only gastrointestinal symptoms (nausea, vomiting, abdominal pain, and diarrhea), or only skin rashes observed. The oxygen saturation of the blood is greater than 95%.
In the asymptomatic form, clinical manifestations of the disease are completely absent, and only SARSCoV-2 RNA is detected in the laboratory.
The analysis of approaches to the gradation of the severity of pathology in children makes it possible to differentiate the features of international and national practices. It is worth noting that the classifications do not contradict each other. At the same time, WHO offers a single classification for children and adults. In the Russian recommendations for pediatrics, the classification of the severity of COVID-19 in children is highlighted separately (
Table 1).
Table 1. Approaches to the identification of the severity of COVID-19 in pediatrics
[31][32][53][31,32,53].
No |
WHO Approaches |
Approaches in Russian Practice |
1. |
Unified classification of forms and severity of the disease for all ages. |
Different classifications for children and adults. |
2. |
3–4 forms of gravity. |
5 forms of gravity. |
3. |
The classification does not provide. specific criteria by which the patient should be assigned to a particular form of severity. |
The classification details the symptoms and results of examinations that allow the patient to be attributed to one form or another of severity. |
4. |
Oxygen saturation of the blood in severe form should be less than 90%. |
Oxygen saturation of the blood in severe form should be less than 93%. |
5. |
The critical form includes “sepsis, septic shock”. |
“Sepsis” and “septic shock” are prescribed as complications. |