Viral pneumonia is an acute inflammation of the respiratory sections of the lungs caused by viral pathogens, occurring with a syndrome of intoxication and respiratory disorders. In childhood, viral pneumonia accounts for about 90% of all cases of pneumonia. In the structure of adult morbidity, bacterial pneumonia predominates, and viral pneumonias account for 4–39% of the total number (people over 65 years of age are more likely to get sick). The frequency of occurrence of viral pneumonia is closely related to the epidemiological outbreaks of SARS - their rise occurs in the autumn-winter period. In pulmonology, primary viral pneumonia (interstitial with a benign course and hemorrhagic with a malignant course) and secondary (viral-bacterial pneumonia - early and late) are distinguished.
Causes of viral pneumonia
The spectrum of causative agents of viral pneumonia is extremely wide. The most common etiological agents are influenza A and B viruses, parainfluenza, adenovirus. Individuals with immunodeficiencies are more susceptible to viral pneumonia caused by the herpes virus and cytomegalovirus. Pneumonias initiated by enteroviruses, hantavirus, metapneumovirus, Epstein-Barr virus are less commonly diagnosed. SARS-associated coronavirus is the causative agent of severe acute respiratory syndrome, better known as SARS. In young children, viral pneumonias are often caused by respiratory syncytial virus, measles, and varicella.
Primary viral pneumonia manifests itself in the first 3 days after infection, and after 3-5 days the bacterial flora joins, and the pneumonia becomes mixed - viral-bacterial. Persons at increased risk of viral pneumonia include young children, patients over 65 years of age, people with weakened immune systems, cardiopulmonary pathology (heart defects, severe arterial hypertension, coronary artery disease, chronic bronchitis, bronchial asthma, pulmonary emphysema) and others. associated chronic diseases.
The transmission of viruses is carried out by airborne droplets when breathing, talking, sneezing, coughing; a contact-household route of infection through contaminated household items is possible. Viral particles penetrate into the respiratory sections of the respiratory tract, where they are adsorbed on the cells of the bronchial and alveolar epithelium, causing its proliferation, infiltration and thickening of the interalveolar septa, round cell infiltration of the peribronchial tissue. In severe forms of viral pneumonia, hemorrhagic exudate is found in the alveoli. Bacterial superinfection significantly aggravates the course of viral pneumonia.
Symptoms of viral pneumonia
Depending on the etiological agent, viral pneumonia can occur with varying degrees of severity, complications, and outcomes. Inflammation of the lungs usually joins from the first days of SARS.
Thus, the defeat of the respiratory sections of the respiratory tract is a frequent companion of adenovirus infection. The onset of pneumonia in most cases is acute, with high fever (38-39°), cough, severe pharyngitis, conjunctivitis, rhinitis, and painful lymphadenopathy. The temperature in adenoviral pneumonia lasts for a long time (up to 10-15 days), it is characterized by large daily fluctuations. Frequent, short cough, shortness of breath, acrocyanosis, various wet rales in the lungs are characteristic. In general, adenoviral pneumonia is distinguished by a long-term preservation of clinical and radiological changes, a tendency to a recurrent course and complications (pleurisy, otitis media).
The incidence of viral pneumonia against the background of influenza increases significantly during periods of epidemics of a respiratory infection. In this case, against the background of typical symptoms of SARS (fever, severe weakness, myalgia, catarrh of the upper respiratory tract), noticeable shortness of breath, diffuse cyanosis, cough with rusty sputum, wheezing in the lungs, chest pain when inhaling. In children, general toxicosis, anxiety are expressed, vomiting, convulsions, meningeal signs may occur. Influenza pneumonia is usually bilateral, as evidenced by auscultatory findings and x-ray picture (focal opacities in both lungs).
Mild cases of viral pneumonia caused by the influenza virus are characterized by mild symptoms and end in recovery. Severe forms occur with constant high fever, respiratory failure, collapse. Among the complications are frequent influenza encephalitis and meningitis, otitis, pyelonephritis. The addition of a secondary bacterial infection often leads to lung abscesses or pleural empyema. Possible death during the first week of the disease.
Parainfluenza pneumonia often affects newborns and young children. It has a small-focal (less often confluent) character and proceeds against the background of catarrhal phenomena. Respiratory disorders and intoxication syndrome are moderate, body temperature usually does not exceed subfebrile values. Severe forms of viral pneumonia with parainfluenza in children occur with severe hyperthermia, convulsions, anorexia, diarrhea, and hemorrhagic syndrome. A feature of respiratory syncytial pneumonia is the development of severe obstructive bronchiolitis. The defeat of the lower parts of the respiratory tract is marked by an increase in body temperature up to 38–39 ° C, a deterioration in the general condition. Due to spasm and blockage of small bronchi with mucus and desquamated epithelium, breathing becomes sharply difficult and rapid, cyanosis of the nasolabial and periorbital region develops. The cough is frequent, wet, but due to the increased viscosity of sputum, it is unproductive. With this type of viral pneumonia, attention is drawn to the discrepancy between intoxication (moderately expressed) and the degree of respiratory failure (extremely pronounced).
Enteroviral pneumonia, the causative agents of which are Coxsackie and ECHO viruses, proceed with poor physical and radiological data. In the clinical picture, concomitant meningeal, intestinal, and cardiovascular disorders come to the fore, making diagnosis difficult.
Diagnosis and treatment of viral pneumonia
Correctly recognizing the etiological form of pneumonia and identifying the pathogen will help a thorough study of the anamnesis, epidemiological situation, assessment of physical and laboratory and radiological data. Viral pneumonia usually develops during periods of epidemic outbreaks of SARS, occurs against the background of catarrhal syndrome, and is accompanied by signs of respiratory failure of varying severity. On auscultation, fine bubbling rales are heard in the lungs.
An x-ray of the lungs reveals an increase in the interstitial pattern, the presence of small focal shadows more often in the lower lobes. The study of sputum, tracheal aspirate or bronchial washings by the method of fluorescent antibodies helps to confirm the viral etiology of pneumonia. In the blood in the acute period, there is a fourfold increase in antibody titers to the viral agent.
A comprehensive assessment of objective data by a pulmonologist will allow to exclude atypical, aspiration pneumonia, obliterating bronchiolitis, heart attack-pneumonia, bronchogenic cancer, etc.
Hospitalization for viral pneumonia is indicated only for children under 1 year old, patients of the older age group (from 65 years old), and those with severe concomitant diseases (COPD, heart failure, diabetes mellitus). Patients are prescribed bed rest, drinking plenty of water, fortified, high-calorie meals.
Etiotropic therapy is prescribed depending on the viral pathogen: rimantadine, Tamiflu, Relenza - for influenza pneumonia, acyclovir - for herpes viral pneumonia, ganciclovir - for cytomegalovirus infection, ribavirin - for respiratory syncytial pneumonia and hantavirus damage, etc. Antibacterial agents are added only with a mixed nature of pneumonia or the development of purulent complications. As a symptomatic treatment, expectorants, antipyretics are used. In order to facilitate the discharge of sputum, medicinal inhalations and drainage massage are carried out. With severe toxicosis, intravenous infusion of solutions is carried out; with the development of respiratory failure - oxygen therapy.
Forecast and prevention of viral pneumonia
In most cases, viral pneumonia ends in recovery within 14 days. In 30-40% of patients, a protracted course of the disease is noted with the preservation of clinical and radiological changes for 3-4 weeks, followed by the development of chronic bronchitis or chronic pneumonia. Morbidity and mortality from viral pneumonia is higher among young children and elderly patients.
Prevention of viral pneumonia is closely related to the immunization of the population, primarily preventive seasonal vaccination against influenza and the most dangerous childhood infections. Nonspecific measures to strengthen immunity include hardening, vitamin therapy. During periods of outbreaks of acute respiratory viral infections, it is necessary to take personal precautions: if possible, exclude contacts with patients with respiratory infections, wash hands more often, ventilate the room, etc. These recommendations especially concern the contingent of increased risk for the development and complicated course of viral pneumonia. Where can i buy bactrim