Parainfluenza
Causes and symptoms of parainfluenza
Parainfluenza is an acute viral disease characterized by damage to the upper respiratory tract, most often the larynx, accompanied by mild intoxication.
For the first time the parainfluenza virus was isolated in Japan in 1952, a couple of years later R. Chanok discovered new pathogens of this disease, which have much in common with influenza viruses, like the pathogens discovered the day before in Japan. In 1959, the isolated viruses were given the name parainfluenza.
Parainfluenza causes
Parainfluenza is caused by a virus. The causative agent of parainfluenza is classified as an RNA genomic virus (genus Paramyxovirus, family Pagatuxoviridae). Depending on the structure of antigens, four types of virus are distinguished, the first three being similar to each other. The combination of antigens is fairly constant. Parainfluenza pathogens can multiply rapidly in living tissues, they are characterized by hemadsorbing and hemagglutinating properties. Viruses have a tropism in relation to the epithelial cells of the respiratory tract, are quickly inactivated by external environmental factors. At room temperature, viruses die in 4 hours, temperatures above fifty degrees destroy viruses in half an hour.
Parainfluenza is spread by airborne droplets. The source of infection is a patient in whom the clinical symptoms of the disease are expressed in one form or another. In the first two or three days, the risk of transmission of infection is maximum, in the next ten days, the risk of infection also exists, but the probability is significantly reduced.
People are very susceptible to parainfluenza viruses. The immunity that occurs after a previous illness passes quickly, so there is a high likelihood of a new infection, and parainfluenza with re-infection is easier. Infants under the age of six months retain passive immunity and, if infected, the disease progresses in a milder form.
When breathing, parainfluenza viruses enter the mucous membranes of the upper respiratory tract and penetrate the epithelium, causing cell reproduction in the nasal cavity, larynx and trachea. The destruction of the mucosal epithelium is accompanied by an inflammatory reaction, which is characterized by the classic symptoms: redness and swelling. In most cases, the larynx is affected, which becomes the cause of false croup, which is widespread among children. The inflammatory process is characterized by slow development. Penetrating into the bloodstream, viruses can cause viremia of low intensity, rather quickly passing, with moderately pronounced symptoms of intoxication.
Parainfluenza symptoms
Symptoms of parainfluenza are very common among persons serving in the army and in children's groups. Viruses of the 1st, 2nd and 3rd types are widespread and can cause parainfluenza throughout the year, but the most characteristic of the disease is the autumn-winter seasonality. Parainfluenza pathogens in 20% of cases cause acute viral infection among the adult population and in 30% of cases cause ARVI in children. The disease can manifest itself in isolated cases and in the form of epidemic outbreaks. Children are most susceptible to parainfluenza, the most vulnerable group is children under one year old.
Symptoms of intoxication with parainfluenza are less pronounced than with influenza, so the disease is milder, but full recovery occurs later.
Depending on the characteristics of the virus itself, the incubation period can last from two to seven days. The disease develops gradually, symptoms of intoxication are mild. Parainfluenza is accompanied by headache, lethargy, chills, general malaise, a feeling of body aches. In most cases, the temperature is subfebrile, severe fever with high body temperature values in the first days of the disease or in certain periods of the disease is possible.
The characteristic symptoms of parainfluenza are noticeable literally from the first hours: these are signs of damage to the upper respiratory tract. The patient, as a rule, has a stuffy nose, a dry (barking) cough, a sore throat, and hoarseness.
During the examination, the doctor notes a slight redness, in rare cases, edema of the mucous membranes and the posterior pharyngeal wall, sometimes edema and granular structure of the soft palate. The work of other organs and systems is not disturbed. In young children and adults with a history of chronic respiratory diseases, the inflammatory process can spread to the lower respiratory tract and contribute to the development of bronchitis.
Adults in most cases tolerate parainfluenza more easily than children. The medical literature describes cases of diseases proceeding in a rather severe form with severe symptoms of intoxication, hallucinations, with complications in the form of inflammation of the meninges. If the disease lasts more than two weeks, then after the disappearance of the main symptoms, asthenic syndrome is still observed for some time.
The symptoms of parainfluenza can cause a number of complications, the nature of which depends on the patient's age. In children of younger preschool age, the most dangerous complication is false croup. Its cause is often a rapidly growing edema of the mucous membrane and spastic contraction of the muscles of the larynx, accompanied by stagnation of secretions. False croup begins acutely, most often at night. The child wakes up from a paroxysmal cough, is worried, frightened, may involuntarily urinate in bed. Breathing is difficult, the skin of the nasolabial triangle has a bluish tinge, the voice is hoarse or hoarse, the heart rate is above normal and increases over time.
Among adults, the most common complication of parainfluenza in the form of a secondary bacterial infection, namely pneumonia. The disease is mainly focal in nature, but, nevertheless, it can last for a long time. As a complication of parainfluenza in some cases, patients may experience sinusitis, otitis media or tonsillitis.
Parainfluenza treatment
Parainfluenza treatment is usually symptomatic. The patient usually does not need hospitalization. Of the drugs, antiviral drugs (for example, amiksin) sulfonamides can be recommended, which are prescribed in the event of complications in the form of pneumonia, otitis media, tonsillitis, etc. With stenosis of the larynx (false croup), hospitalization is necessary. The patient needs a hot foot bath, steam inhalation. Of the drugs, corticosteroids and chlorpromazine in the form of an injection solution are shown.
Isolation of the patient is recommended. It should be in a separate room, which must be ventilated daily and wet cleaned in it. In case of outbreaks of parainfluenza in children's institutions, inhalation of interferon twice a day is recommended throughout the entire period of the rise in incidence. Interferon solution can also be instilled into the nose 3-4 times a day. For prophylaxis, adults can use oxolinic ointment for intranasal administration 1-2 times a day.
Article author: Mochalov Pavel Alexandrovich | d. m. n. therapist
Education: Moscow Medical Institute. IM Sechenov, specialty - "General Medicine" in 1991, in 1993 "Occupational Diseases", in 1996 "Therapy".
