The pandemic of COVID-19 generated the global collapse of economic life and infrastructure, limited freedom of movement of people. This respiratory infection is unprecedented because strikes the most vulnerable, peripheral part of a bronchopulmonary tree of the person, namely an alveolus which are responsible for blood saturation by oxygen, a body, necessary for all fabrics.
In December, 2019, in Wuhan, the Province of Hubei in China, messages about the outbreak of a high-contagious viral infection appeared. At first it was reported that it is an extra hospital form of pneumonia. Subsequently recognized that there is an etiological agent, actually new coronavirus. Never earlier the mankind faced this agent and has to it no immunity, according to descriptions all range of clinical manifestations — from easy forms, even asymptomatic course, prior to the fatal cases connected with damage of airways took place. SARS-CoV-2. The etiological agent of COVID-19 struck patients from many countries and generated the global crisis connected with medicine, economy and psychological consequences of huge scale. On January 30, 2020 the World Health Organization announced flash of SARS-CoV-2 emergency situation of the international value in the field of public health care.
Most of people with symptoms of this infection has a productive reaction and the easy immune mediated syndrome with limited damage of tissues of lungs. At more than 80% infected easy, moderate disease with flu symptoms will take place though it is obvious, these symptoms will differ from symptoms at other infections. Approximately in 20% of cases the virus causes a catastrophic series of the activated immune responses which can end with irreversible destruction of alveoluses that leads to the actual collapse of a system of gas exchange.
Never before the civilization faced more frightening opponent, absolutely invisible, with symptoms which cannot be identified, it is the most infectious smallest agent from known today, besides, we deal with the fastest spread of a virus in the history of observations. The SARS-CoV-2 virus has characteristics which can lead to one of the most painful diseases known to modern medicine.
At first the SARS-CoV-2 virus plans to itself a binding site through which he ensures virus tropism. The superficial glycoprotein, "thorn" of the SARS-Cov-2 virus clings to a receptor of an angiotensin-converting enzyme (APF2) which is widespread on all organism. The coronavirus has special tendency to get into terminal (trailer) departments of a bronchopulmonary system, especially into the system of alveolar gas exchange which provides continuous intake of oxygen for its subsequent delivery to all body tissues. Then, while most of patients will have an adequate coordinated and strictly adjustable immune response of an organism on this etiological agent, about 20% infected will suffer from consequences, start of productive activation of system immune and inflammatory crisis. The subsequent answer of an organism involves all components of the immune system.
The sites affected with a virus include the most vulnerable and sensitive elements of the life support system, there is a catastrophic defeat of the alveolar device due to excess of dangerous extreme value of a damage threshold of alveoluses. Excess of a limit damage threshold — 600 million alveoluses — leads to blood saturation collapse by oxygen and oxygen deliveries that does useless any measures, leads to hypoxemic ischemia of bodies and death. Reference of a concrete disease to hard cases can be determined by number of risk factors and clinical manifestations.
As risk factors for reference of diseases to hard cases were recognized: male, advanced age, previous unhealthy living conditions, especially, hypertensia, diabetes, obesity and smoking. The clinical picture for most of hard struck patients, as a rule, includes intersticial pneumonia with fast transition to acute respiratory a distress syndrome, to septic shock with signs of release of reagents of an acute phase in connection with activation of macrophages. Besides, increase With - jet protein and D-dimera correlates with dysfunction of a liver and a giperferritinemiya and can be followed by the IDCS (disseminate intravascular coagulation).
Thus, lungs are the main and key target at patients with heavy COVID-19, but as the field of distribution of ACE-2-receptors is rather wide, it is necessary to define whether injuries of kidneys, digestive tract, heart, skin, the central and peripheral nervous system are hypoxia consequences, or the virus aiming of a virus at an endothelium in these fabrics takes place. This question can become a subject for the subsequent scientific research.