Infectious diseases



SARS photos SARS - polietiologichesky this group of pathologies of infectious origin, with a similar clinical picture, the development of which is caused by the defeat of the respiratory system, and in complicated and other organs and systems.On the basis of the terminology, the diagnosis of "SARS» installed only with reliable laboratory confirmation of the fact of the presence of the virus in the epithelial cells of the pathogen.

When a patient does not have the SARS virus, doctors used the diagnosis of "acute respiratory illness."This separation is essential becauseUnder these two conditions significantly different patient management.

highest incidence of SARS occurs in winter and early spring, although some cases of the disease recorded in the infectious disease throughout the year.Conscious of the fact that as the causative agent of SARS may act by representatives of various viruses and the immune system in humans is produced exclusively for a particular virus, which is the cause of SARS dur

ing the year can be seen a few episodes of the disease.

Repeated episodes of acute respiratory viral infections in children provoke the development of lowering the body's resistance to the effects of various viral agents immunodeficiency states such as transient, delayed psychomotor and physical development of sensitization.

Causes SARS

only causative factor in the development of SARS is the introduction of the virus into the human body, characterized by affinity for the mucous membranes of the respiratory system.Infectiologists after numerous randomized studies concluded that almost 90% of cases of respiratory disease caused by exposure to a viral infection in the human body and only 10% are of bacterial origin.During the epidemic of SARS affected every year at least 20% of the population, and are accompanied by infection with the pandemic to 50% of the population.

view of the rapid development of diagnostic technologies in the field of virology, now specialists have found up to two hundred different types of viruses that under certain conditions, can provoke the development of SARS.The most common causative agent of SARS is a flu virus, characterized by severe virulence, but among the originators of SARS have been increasingly identified types of infections such as adenovirus, rhinovirus, each of which has specific manifestations.

Regardless of the specificity of the causative agent of SARS, the source of infection is a person with clinical manifestations of the disease, especially if there is an acute SARS.The infection is classified as highly contagious as the primary mode of transmission is airborne, it is hit or that the virus of SARS in the body of a person occurs through close contact with a sick person by the transfer of infected small particles of saliva released during a conversation and coughing.

Another common lately mechanism of transmission of SARS is a pin, which is a long time did not have the evidence base.Infection by contact with SARS happens when a sick person when sneezing or coughing brings to the mouth and hands does not handle them then disinfecting agents.As a result, after touching contaminated hands to everyday objects become infected environment.SARS viruses are characterized by high resistance to environmental factors, so the spread of the contact method may take some time.

for the development of SARS is very important concentration of the virus in the environment.So, the minimal amount of virus reaches the mucous membranes, the smaller the percentage likelihood of developing the disease.High saturation viruses stored in a closed space, especially with the large crowds.The lowest concentration of virus, in contrast, is celebrated in the open air.

Note that not all cases of contact with a sick person healthy SARS is the development of the disease, and it depends on the level of natural immunity.People who do not suffer from chronic diseases, malnutrition and exposure to stress, as a rule, do not suffer from SARS, as they have not observed impaired immunity.

so-called "gateway" for the virus of SARS are organs of the upper respiratory tract, conjunctiva, and in some cases, and the mucous membranes of the digestive tract.All the viruses that cause the development of clinical manifestations of SARS are classified epiteliotropnyh.After contact with the nasal or oral cavity of SARS virus is its adsorption in the cytoplasm of epithelial cells, where it is subjected to the disintegration under the action of cytoplasmic enzymes.A reproduction of the virus causes the development of degenerative changes in epithelial and inflammatory reactions of the mucous membrane of the nasal cavity.

If we consider the question of the specificity of each virus tropism in relation to the different tissues of the human body, it must be concluded, influenza virus, adenovirus and respiratory syncytial virus infects epithelial cells of the respiratory tract all the way from the nose to the alveoli.Rhinovirus infection is characterized by lesions of the nasal epithelial cells exclusively, and parainfluenza virus affects the larynx.The only representative of viruses belonging to the group of SARS that affects the conjunctiva of the eye is an adenovirus.

After the destruction of epithelial cells occurs SARS virus from entering the bloodstream and duration of viremia depends on the severity of dystrophic epithelial damage, immune status and specificity of the human virus.Intoxication syndrome develops in humans as a result of contact with the blood of high concentration of the decay products of epithelial cells that have toxic and toxic-allergic effect.The more toxic effects on the structure of the virus is the central nervous and cardiovascular systems.

development of bacterial complications caused by violation of the barrier function of the epithelium of the respiratory system.

symptoms and signs of SARS

Of course, each of the etiopathogenetic variants SARS accompanied by the development of specific pathognomonic symptoms that distinguish it from other variants of the flow, however, there is a common clinical symptom, one of the symptoms that occur in all patients suffering from SARS.So a classic version of course is the presence of SARS symptoms obscheintoksikatsionnogo syndrome as fever, muscle pain, headaches, progressive weakness, fever, and signs of lesions of the respiratory tract.

initial manifestations of destruction of the respiratory symptoms is the development of so-called catarrhal syndrome in the form of nasal congestion and the emergence of abundant secretions from the nasal passages, sore throat and pain when swallowing, burning sensation in the eyes, increased lacrimation.All these symptoms are caused by excessive swelling of the mucous membranes in these organs, arising as a result of the inflammatory process that occurs in response to the introduction into the body of the virus SARS.In catarrhal period, patients are more concerned about a cough with SARS, which is a dry paroxysmal in nature and is not accompanied by phlegm.

way, sneezing should not be regarded as a symptom of the disease, since it is probably a reflex act aimed at cleansing the respiratory tract from foreign objects and dust particles.Provoking factor for the development of human sneeze is the transition from the room with cold air into a warm room.

principal difference is the prevalence of influenza in clinical manifestations of intoxication symptoms of respiratory disorders, in contrast to the parainfluenza, for example, in which the foreground laryngitis.

Unfortunately, SARS rarely occurs in classical clinical variants, a recent increase in cases of very severe atypical course of the disease, although uncommon and completely asymptomatic forms of SARS.That option is atypical SARS without fever.Latent during SARS, on the other hand, is dangerous, because the minimum clinical manifestations do not cause disturbances of human health and the patient does not consider it necessary to seek medical help, while SARS can be provoked by such dangerous pathogens as meningococcus, which is as soon as possible contributes to the development of sepsisand serious damage to brain structures.

The symptoms of SARS, requiring attention from the patient and the physician are: pronounced increase in body temperature of the patient, is not stopped taking antipyretics, short-term and long-term episodes of loss of consciousness, severe pain in the head region of the diffuse nature of the appearancediffuse rash of star character with a hemorrhagic component, respiratory disorders by type of increasing shortness of breath, cough with bloody sputum character.

long for the clinical manifestations of SARS, continued for more than seven days, is classified as complicated SARS in need of skilled care professional in a hospital infection profile.Some patients may be celebrated long standby after SARS, and this state is the foundation for further examination of the patient.

Each of infections related to the category of SARS, characterized by specificity of clinical manifestations.So, parainfluenza is characterized by a slow onset of the clinical picture of a moderately severe intoxication syndrome and low temperature rise.A characteristic pathognomonic sign of SARS provoked a sharp parainfluenza virus hoarseness, sore throat and a dry hacking cough.

SARS provoked by the defeat of the body rhinovirus, is characterized by the appearance of the patient's discharge from the heavy watery nasal mucous character with minimal manifestations of intoxication syndrome.In addition, the patient worried about tearing, sneezing.For SARS, caused by rhinovirus infection is not characterized by a significant increase in body temperature, so most adult patients safely carry the disease.

Adenovirus infection is a bright representative of SARS, characterized by lesions of not only the epithelium of the respiratory system and lymphoid tissue that causes the appearance of the patient's symptoms of lymphadenitis in the form of increased, painful lymph nodes of different groups, hepatosplenomegaly, nonspecific pain in the abdomen anddyspeptic disorders.In addition, the pathognomonic symptoms of SARS caused by adenovirus infection is the appearance of abundant mucus from the nasal passages, asymmetric conjunctivitis, mild cough on the fourth day of the disease, effects of tonsillitis.The duration of fever is on average seven days.

respiratory syncytial infection manifests a primary lesion of bronchus and lung parenchyma, thus leading clinical symptoms of SARS in this situation is prolonged cough, growing respiratory disorders due to bronchospasm.Catarrhal symptoms for this type of uncommon or SARS appear minimal.

Diagnosing SARS

main focus in the diagnosis of SARS is a thorough collection of epidemiological history of the disease, the patient's complaints and conduct a comprehensive physical examination of the patient.The first task is to assess the infectious disease SARS severity and intensity of intoxication syndrome.

Given the fact that the development of acute respiratory viral infection can be triggered by various representatives of the virus, is currently used for the verification of pathogen-specific methods of laboratory diagnostics in the form of rapid methods and PCR.The principle of this research is based on the determination of antigens of respiratory viruses in preparations of the columnar epithelium of the nasal passages, which uses a sampling method "print" from the mucous membranes of the nasal cavity.

highly specific diagnosis of SARS is a method of detecting neuraminidase activity.Until recently, the widely used technique of virological and serological testing using enzyme immunoassay, complement fixation, hemagglutination inhibition, but due to the complexity of their implementation at present these techniques are not used in the diagnosis of SARS.

SARS, just like any other viral disease characterized by the appearance of changes in the overall analysis of the blood in the form of increase in the index of lymphocytes and erythrocyte sedimentation rate.When uncomplicated SARS WBC does not change.

greatest importance in the practice of the physician is to establish a definite diagnosis, which are available at the patient's symptoms and effects should be differentiated from diseases with similar clinical picture.With respect to priority infectious disease SARS is the determination of the virus trigger the development of the disease as it affects the further tactics of the patient.

Treatment of SARS

Despite the great advances in the field of pharmacology for effective anti-virus is not achieved positive results such as with antibiotics.Lack pronounced effect due to the fact that viruses are characterized by intracellular multiplication, unlike bacteria.In these circumstances, the only mechanism to combat SARS virus is to destroy cells infected by viruses.

In recent decades, several groups of drugs are used, having proven effectiveness for the elimination of viral infections which cause the SARS, as blockers of M2-channels and neuraminidase inhibitors.At the present time all the efforts of pharmacological laboratories focused on developing drugs that are active against such viruses as rhinovirus and koronarovirus, and this interest is due to an increase in the incidence of SARS caused by these viral agents.

most common drug of SARS "Remantadin" refers to a group of pharmacological blockers M2-channel is now used exclusively for the treatment of influenza A, and its efficiency is not less than 70% of cases of influenza infection.Proven rimantadine in the treatment of influenza-like illness and SARS is only 25%.

more effective cure for SARS, "Oseltamivir", referring to a group of antiviral drugs used primarily in oral form and can be used even for patients infants.The effective daily therapeutic dose of Oseltamivir 75 mg twice a day, after taking which marked reduction in the incidence of morbidity SARS, reduced the duration of symptoms.

Prophylactic use of Oseltamivir in a reduced daily dose of 75 mg to prevent the development of SARS.Oseltamivir belongs to the antivirals that have minimal side effects as nausea, moderately expressed headache, weakness and insomnia, which are not an indication for termination of antiviral therapy.The duration of therapy of oseltamivir in patients with uncomplicated acute respiratory viral infection is five days.

Another representative of antiviral drugs effective in the treatment of SARS is zanamivir, which is used exclusively in the form of an inhalation form, the daily dose which should be 20 mg.Adverse reactions Zanamivir include: feeling sore throat, bronchospasm, severe pain in the head, and therefore, the drug is contraindicated in persons under the age of 7 years.

greatest efficacy against RSV infection has ribavirin.