Infectious diseases



Flu photos Influenza - a disease of infectious origin, resulting from the damaging effect of influenza virus of a particular serotype in the epithelial cells of the mucous membrane localization with the priority in the upper airways.Many people are mistaken for the flu banal colds and do not carry out effective measures for relief of exposure to the virus and prevent infection of persons in contact with the sick person.

clinical signs of influenza especially in subacute its course are similar to symptoms of other diseases of infectious origin, agents that affect the respiratory system.In this situation, for quality verification of the diagnosis is mandatory the use of specific laboratory tests.

Given the global statistics, you can claim that about 15% of humanity in the world suffer from the flu each year.A strong flu become the most common cause of irreversible damage to the structures of the cardiovascular system and brain.

reasons flu

flu occurs when the body's infection-genomic RN

A virus genus Influenzavirus, belonging to the family Orthomyxoviridae.Currently, virologists was found three types of influenza viruses, namely A, B, C. By type of virus implied a certain set of endogenous antigens that do not show pronounced immunogenicity.Influenza A viruses can infect not only humans, but also in some animals, birds, whereas viruses of type B and C only provoke the development of influenza in humans.

In regard to the formation of the immune response of the human body in response to infection with influenza the most important role played by the surface antigens of the virus in a hemagglutinin and neuraminidase.The most virulent, and thus the spread of epidemic influenza A virus has

characteristic feature of all types of influenza virus is the ability to change the composition of the antigen by the "drift" or "shift".The term "drift" refers to a partial modification of the antigenic properties, while the "shift" is a complete replacement of the region of the genome responsible for the synthesis coding hemagglutinin and neuraminidase.

a result of the antigenic "shift" there are many subtypes of the influenza A virus, which is its specific feature.The variability of the antigenic properties of influenza viruses to provoke the sudden emergence of epidemics of this viral disease.

influenza virus almost never causes massive outbreaks, as has minimal variability.Note that the influenza virus to inhibit the effects of low or sufficiently high temperatures for several days, and disinfectants all pathogen inactivated within a few minutes.

Like all infections, the flu spreads from the source to a susceptible host.As a source of influenza appears sick person, having obvious clinical manifestations or erased.The peak of infectiousness falls on the first six days of the disease.In the case of complicated influenza can occur over a long period of abjection flu.Virology not proven latent virus carrier of the flu.In the last decade worldwide virologists note increase in the incidence of influenza in the human infection of animals and birds.

main mechanism of spread of influenza virus is an aerosol, that is, through droplets of mucus and sputum, transmitted by airborne droplets.The degree of resistance of influenza virus in these secretions depends not only on the dispersion of the aerosol, but also on environmental factors.Experienced infectious diseases also do not exclude the possibility of infection with influenza household waste.

New serotypes of influenza virus have a high specificity for the human body, which leads to increased susceptibility of humans to infection.In view of the rapid variability of the antigenic properties of the influenza virus, even children who are breastfed are at risk, and for influenza among children in the neonatal period is heavier than in the mother.

Influenza belongs to the category of infectious diseases that are spread everywhere and are accompanied by a display of epidemic outbreaks that cover most of the population and are not only medical but also social problem.In the overall structure of infectious pathologies of the flu is at least 70%.

peak incidence occurs in autumn-winter period, although outbreaks can develop at any time of the year.Fortunately, the mortality rate of influenza is less than 5% and the cause of death is not so much the flu, how a bacterial infection.

rapid spread of influenza caused by a short incubation period, by the airborne transmission of the virus, the high susceptibility of the human organism to the pathogen influenza, as well as the social conditions of life.

Considering the pathogenesis of influenza, it should be noted that the maximum multiplication of the virus occurs on the mucous membranes of the upper respiratory tract thanks to its epiteliotropnosti.As a result, the damaging effect on the epithelial cells of the mucous membranes of the accumulation of bacteria which enhance the inflammatory response and promote the sensitization.The inflammatory response in the mucous membranes developed under option "dry catarrh", that is not accompanied by the development of productive processes.

short incubation period for influenza is due to the rapid reproduction of the virus.

The flu is not characteristic of damage to the lung parenchyma, but the elderly and children because of the location of the anatomical features of the respiratory system in some situations going on influenza virus lung damage.

After breeding in the epithelial cells of the mucous membranes of the respiratory tract influenza virus enters the bloodstream and duration of viremia in the average is 14 days.The influenza virus does not cause the release of their own toxins, so intoxication syndrome, the flu is caused by the accumulation of endogenous substances with biological activity.The result of the impact of influenza hemagglutinin in the red blood cells, is the activation of intravascular thrombus formation and development of DIC.

In severe influenza and severe viremia occurs hematogenous spread of the virus in all the organs, causing microcirculatory disturbances and the subsequent development of degenerative changes.

Symptoms and signs of influenza

Flu refers to infectious diseases with a short incubation period of not more than three days.The disease is mild, moderate and severe uncomplicated form or accompanied by the development of complications.The basis of the clinical course of uncomplicated influenza variant is three symptom: intoxication, catarrhal and hemorrhagic.

Manifestation of symptoms of intoxication are leading and are characterized by a sharp rapid onset of the disease.Febrile temperatures the flu develops in the early hours of the development of the disease and is accompanied by a strong chill.Patients suffering from the flu, in acute complained of severe pain in the front of the head, the progressive general weakness, inability to perform even minimal physical activity.The consequence of microcirculatory disorders in muscles is the emergence of a human painful sensations throughout the body, dizziness and nonspecific pain in the joints.In pediatric patients intoxication accompanied by the development of increased seizure and transient loss of consciousness.

Headaches with influenza can vary from the minimum that is observed in the elderly patient category of persons to sudden, often accompanied by the appearance of insomnia, hallucinations and multiple episodes of vomiting.

hectic type of fever reaches its peak by the end of the first day of illness, after which, as a rule, there is a decrease in the patient body temperature.In some cases, there may be a so-called "second wave of fever," that is another peak heat, which is docked only on the fifth day of illness.

objective signs of flu is the appearance of the patient's face and conjunctival hyperemia eyes, scleritis, dryness of the skin.Symptoms of degenerative myocardial injury is the appearance of muffled heart sounds on auscultation, and listening systolic murmur at the apex.Pathognomonic signs of intoxication syndrome, the flu is the appearance of tachycardia and hypotension.

Joining catarrhal manifestations of symptoms observed after a few days of the onset of the disease, and in some situations, they may be completely absent.Typical signs of catarrhal syndrome, the flu is the appearance of dry, sore throat and pain in the nasopharynx during swallowing even liquid food, nasal congestion.

An objective examination of the patient suffering from influenza in the catarrhal stage is marked congestive redness, dryness and swelling of the mucous membranes of the nasopharynx and oropharynx.A notable fact is the presence of nasal breathing difficulty in the absence of discharge from the nasal passages.Characteristic signs of catarrhal period with influenza symptoms are Laryngotracheitis a rawness and pain in the chest, rapid breathing and a dry hacking cough.Cough with flu so intense that provokes an attack of vomiting and severe muscle pain in the epigastric region, and hypochondria.

Given the level of intoxication syndrome and severity of catarrhal symptoms can be divided into several flu severity.

For mild flu accompanied by a slight rise in temperature not exceeding 38 ° C, mild headache and catarrhal symptoms.The objective signs of intoxication syndrome in the case of a light flow of influenza is a heart rate less than 90 beats per minute at constant blood pressure.Respiratory disorders are not typical for mild flu.

moderate forms of influenza accompanied by the development of fever febrile type of hemodynamic disorders in the form of increased heart rate and a decrease in systolic blood pressure of moderate severity.

Severe flu is accompanied by prolonged fever with high temperature, skin, sharp hemodynamic disorders and compensatory quickening respiration rate.

During an epidemic, as a rule, marked the development of the typical variants of the flu, while in the period interepidemic prevail incidence of mild cases and atypical forms of influenza.

Fortunately, the symptoms of hemorrhagic syndrome with influenza occur only in 5% of cases and are manifested in the form of pinpoint hemorrhages on the mucous membranes of the oropharynx.Nosebleeds the flu are the exception to the rule.Severe hemorrhagic syndrome, the flu is the development of acute pulmonary edema.

In pediatric age group flu patients can manifest violations of bowel function in the form of loose stools.

Acute flu lasts on average no more than five days, and then develops a long asthenic syndrome, which is also in need of correction.

In some situations, the clinical course of influenza is so non-specific that the establishment of a definite diagnosis is only possible with additional inspection techniques.

influenza diagnostic

In order to verify the accurate diagnosis of "flu" is used as an early and retrospective laboratory diagnostics.In addition, methods of laboratory analysis are used for differential diagnosis between existing patient symptoms of influenza and other infectious diseases with a similar clinical picture.

function of the virology laboratory is the etiological decoding of the incidence of influenza among patients of different ages.Modern virology laboratories are equipped with powerful equipment and diagnostic preparations.

Currently, there are a wide range of laboratory tests establishing the flu, among which there are both rapid methods, as well as virologic, serologic methods for the study.

Express - acute influenza diagnosis involves the use of a fluorescent antibody technique, the principle of which is to identify antigens of the virus in the epithelial cells of the mucous membranes of the nasal cavity and the conjunctiva.A prerequisite for the success of the analysis is the timeliness of the material of the fence, namely no later than the fifth day of the disease.With this technique it is possible not only to determine the fact of infection with influenza virus, but also carrying out the verification of its serotype, which is of fundamental importance in the selection of treatment regimens.

maximum reliability in relation to the diagnosis of influenza has the technique of polymerase chain reaction, the principle of which is based on the definition in laboratory samples of RNA and DNA of the pathogen.To analyze a patient with acute influenza produce biopsy specimens from nasal and oral.In addition to the influenza virus PCR to determine the other agents of respiratory infections, which is important in the case of combined lesions of the body several groups of viruses.

remaining flu virus isolation techniques are labor intensive and time consuming, so most are used for scientific purposes.

Serological analysis is classified as historical methods of laboratory diagnosis, since it is based on the principle of detecting growth of antibody titer in the human body.To analyze the patient's blood sample should be performed in the acute phase and after clinical recovery, and analysis of serum.

Treatment of influenza

decision on the need for hospitalization of patients in a hospital infectious Profile takes the attending physician taking into account the clinical and epidemiological evidence, which include: severe cases of the flu, if the patient has adverse premorbid background, complicated course of the disease.The remaining cases are not subject to compulsory hospitalization and therapy performed on an outpatient basis.

fundamental element of successful treatment is not only the adoption of some drugs against influenza, and patient compliance with recommendations on correction mode and power.All patients suffering from influenza in the acute stage, are obliged to comply with bed rest and use a larger amount of liquid in the form of clean water, juices and herbal concoctions.

Causal treatment involves the use of rimantadine in a specific pattern: in the early days of the disease daily dose is 300 mg, in the second and third days, reduce the dose to 200 mg.Keep in mind that women and children during pregnancy is absolutely contraindicated the tool against the flu.Analogous Oseltamivir has antiviral properties, which is administered orally at 75 mg twice a day, the rate of antiviral therapy is five days.Maximum effectiveness of antiviral treatment of these drugs observed in the event of their application from the first day of the disease.

As regards the application of antibiotics should be said that the area of ​​application are elderly patients with a history of chronic respiratory diseases, as well as persons suffering from immunodeficiency.The remaining cases are uncomplicated influenza are not grounds for antibiotics.

Symptomatic treatment involves the use of ascorbic acid at a dose of 0.1 g three times a day, in routine daily dose of 0.15 g of calcium gluconate in a daily dose of 3 g, 1 Tsetrina 10 mg once a day.

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