Kazakh National Medical University named after sd Asfendiyarov

Аbstract

On the topic: Flu

Finished: Turopova A.

                                                                                     Checked: Derbisalin Zh.A.

Faculty: Stomatology

                                                                   Group St-14-001-01

Almaty 2017

Introduction

Influenza is a type of acute respiratory viral infection, which, as a rule, is considered separately from other diseases of this group. Influenza differs from other infections especially severe course, the presence of complications and can result in death.

Especially quickly it spreads in large cities, where people know firsthand how flu is influenced: Moscow, St. Petersburg, and other cities and regions of Russia are exposed to epidemics of this disease every year.

Influenza is dangerous precisely because of its complications. That is why small children, elderly people, as well as patients suffering from chronic severe heart and lung diseases are at the greatest risk in influenza. In such patients, there are exacerbations of chronic diseases: bronchial asthma and chronic bronchitis, cardiovascular diseases, kidney diseases, metabolic disorders, etc.

Another reason for concern is pregnancy: the flu can seriously damage a child, especially in the early stages of its development. The most unpleasant thing is the threat of miscarriage or premature birth. In addition, the bacterial infection, which can not be treated with antibiotics, often sits on the mother's weakened by the influenza organism.

It is people from the risk group who must first of all use the means of preventing influenza and es

Flu. Relevance. Etiology. Epidemiology.

Clinical picture. Diagnostics. Treatment. Prevention.

Influenza is an acute respiratory anthroponosis infection caused by viruses of types A, B and C, which proceeds with the development of intoxication and the destruction of the epithelium of the mucous membrane of the upper respiratory tract, more often the trachea. The disease is prone to rapid and global spread. Influenza is a highly contagious acute viral disease with an airborne droplet transmission mechanism that occurs with fever, general intoxication, predominant upper respiratory tract infection, frequent complications

pecially be closely monitored by doctors in case of infection.

RELEVANCE

 Influenza is a serious disease that can cause complications in people of any age and health.

 The disease is characterized by a simultaneous lesion of a large

Number of people in one region, which leads to high

For medical care and causes huge economic damage,

Both individuals and society as a whole.

 Additional flu costs associated with disability in working patients during the years of influenza epidemics exceed costs associated with all other acute illnesses.

 Preventing influenza through vaccination can prevent

High incidence of influenza.

 In cases of disease in vaccines, the course of the disease is more favorable, which reduces the risk of post-infectious complications and mortality, especially in the elderly and young children.

 Active preventive interventions in high-risk groups can reduce the magnitude of the epidemic outbreak in individual regions.

Etiology

  Etiology: Influenza A virus

The influenza A virus usually causes a disease of medium or severe severity. It affects both man and some animals (horse, pig, ferret, birds). It is influenza A viruses that are responsible for the emergence of pandemics and severe epidemics. • A number of subtypes of the type A virus are known, which are classified by surface antigens - haemagglutinin and neuraminidase: 16 types of hemagglutinin and 9 types of neuraminidase are currently known. • The virus is species-specific: that is, as a rule, a bird virus can not affect a pig or a person, and vice versa

Etiology: Influenza B virus

The influenza B virus, like the influenza A virus, is able to change its antigenic structure. However, these processes are less pronounced than in type A influenza. Type B viruses do not cause a pandemic and usually cause local outbreaks and epidemics, sometimes involving one or more countries.

  • Type B influenza outbreaks may coincide with those of type A influenza or precede it. Influenza B viruses circulate only in the human population (more often causing disease in children).

  Etiology: Influenza C virus

The influenza C virus has been poorly studied. It is known that unlike viruses A and B, it contains only 7 fragments of nucleic acid and one surface antigen. Infects only the person. Symptoms of the disease are usually very light, or do not manifest at all. It does not cause epidemics and does not lead to serious consequences. It causes sporadic diseases, more often in children. • The antigenic structure is not affected by such changes as type A viruses. Diseases caused by the influenza C virus often coincide with the epidemic of influenza type A. The clinical picture is the same as with the mild and moderately severe forms of influenza A.

The causative agent is the RNA genomic virus of the genus Influenzavirus of the family Orthomyxoviridae. There are three types of viruses known - A, B, C. The type of virus determines a set of internal antigens showing a weak immunogenicity. Influenza virus type A affects a person, some species of animals (horses, pigs, etc.) and birds. Influenza viruses of types B and C are pathogenic only for humans.

Surface Aantigens of influenza viruses - hemagglutinin and neuraminidase. They play an important role in the formation of the immune response of the body in the influenza and allow to separate the influenza type A virus into subtypes H1N1, H3N2, etc. The type A virus has the most pronounced virulent properties and is prone to epidemic spreading. The peculiarity of influenza viruses is their ability to antigenic variability. It can be realized by "drifting" (partial variability of antigenic determinants) or "shift" (complete replacement of a fragment of the genome encoding the synthesis of hemagglutinin or neuraminidase).

Most often, the "drift" occurs in the type A influenza virus, but it also occurs in type B. Antigenic "shift" is a specific feature of the type A virus, leading to the appearance of its new subtypes. High variability of influenza viruses explains the unpredictability of epidemics of the disease.

The type C virus is less variable and causes only small epidemic outbreaks. Influenza virus can persist at a temperature of 4 ° C for 2-3 weeks, heating at a temperature of 50-60 "C causes the inactivation of the virus within a few minutes, the disinfectants rapidly inactivate the virus.

Epidemiology

 Epidemiologically, the fact of isolating the influenza A virus not only from humans, but also from horses, pigs, many species of wild and domestic birds is important. Influenza viruses B and C are isolated only from humans.

Major epidemics of influenza A occur at intervals of 2-3 years, and pandemics - with an interval of about 10-15 years. Epidemics of influenza B occur with an interval of 3-4 years. Influenza caused by type C viruses is noted sporadically or in the form of small outbreaks in closed groups.

The source of infection for influenza is a patient, especially with light, erased and asymptomatic forms, since the diseased is not isolated from the collective. The patient is particularly infectious at the height of the disease, the duration of the infectious period is 4-7 days, can be prolonged up to 10 days.

Infection is transmitted by airborne droplets. Susceptibility to influenza is high. People are sick at any age. Children of the first months of life get sick with flu less often due to the fact that some of them have the immunity received by the transplacental route from the mother. Starting from 6 months. This passively acquired immunity practically disappears from all, and children from this age become especially susceptible to influenza. Days, can be prolonged up to 10 days.

Infection is transmitted by airborne droplets. Susceptibility to influenza is high. People are sick at any age. Children of the first months of life get sick with flu less often due to the fact that some of them have the immunity received by the transplacental route from the mother. Starting from 6 months. This passively acquired immunity practically disappears from all, and children from this age become especially susceptible to influenza.

Thus, the general susceptibility to influenza, unstable type-specific immunity, short incubation period (1-2 days), airborne droplet transmission pathway create favorable conditions for the massive spread of this acute infection.

Pathogenesis PATHOGENESIS OF INFLUENZA INFLUENZA VIRUS Phase 1. Penetration of the pathogen into the respiratory tract Phase 2. Fixation of the virus on the mucosal surface Phase 3. Viral replication in the epithelial cells of the VDP Infectious disease