Measles is an acute infectious disease of viral etiology with an airborne transmission mechanism, characterized by fever, catarrh of the mucous membranes of the eyes, nasopharynx and upper respiratory tract, enanthema and maculopapular rash.
The causative agent is an RNA-containing paramyxovirus, which quickly dies under the influence of sunlight, ultraviolet radiation.
The source of the causative agent of the infection is a person with measles. It is contagious to others from the last 1-2 days of the incubation period until the 4th day after the rash appears. Transmission of the causative agent occurs by airborne droplets. The virus enters the air with droplets of exudate from the patient's upper respiratory tract during a conversation, coughing, sneezing. Infection occurs both in direct contact with the patient, and at a considerable distance from him, since a virus with a current of air can penetrate into neighboring rooms and even to other floors. If a pregnant woman falls ill with measles before giving birth, a transplacental infection of the fetus is possible. In this case, the child born has symptoms of measles. Through a third party, the pathogen is not transmitted; cases of its transmission through household items due to the low resistance of the virus are very rare.
When the measles causative agent is introduced into certain areas where it has not been for many years, as well as into unvaccinated children's groups, almost everyone who has not had measles before, regardless of age, gets sick. In large settlements where migration processes are expressed, children aged 1 to 7 years are more likely to fall ill, in age groups older than 7 years, the incidence decreases rapidly and only 14 cases of measles occur after the age of 14 years. Measles, like all airborne infections, is characterized by seasonality. The maximum number of diseases is recorded from December to May, the minimum - in August-September. Due to mass measles vaccination, the incidence of measles decreased sharply.
The clinical picture . The incubation period is from 8 to 17 days with the introduction of gamma globulin. Its duration may increase to 21–28 days. In typical cases, during the disease, 3 periods are distinguished: catarrhal (initial, prodromal), period of rash and pigmentation. The catarrhal period begins acutely: a runny nose, cough , conjunctivitis , intoxication symptoms (fever up to 38 - 39 ° C, headache , malaise, lethargy, loss of appetite, etc.) appear. The cough is usually a rough, barking, hoarse voice. Croup syndrome may develop. The face becomes puffy, the eyelids and lips swell. Conjunctiva and sclera hyperemia, lacrimation and photophobia are noted. From the 2nd to 3rd day, red spots (enanthema) are found on the mucous membrane of the hard and soft palate. On the mucous membrane of the cheeks at the level of small molars, and sometimes on the mucous membrane of the lips and conjunctiva, small papules (0.5-1 mm in diameter) appear, which have a grayish-white color, rise above the surface of the mucous membrane, surrounded by a corolla of hyperemia. Papules do not merge with each other, firmly soldered to the underlying tissue (not removed with a spatula). These elements are a specific symptom of measles and are called Velsky — Filatov — Koplik spots. They persist for 2 to 4 days and disappear on the first, less often second day of the rash period. After their disappearance, the mucous membrane of the cheeks remains hyperemic and rough for several days. Sometimes in the catarrhal period on the skin, a mild, small-pointed scarlet-like or spotted rash is found on the skin, in some cases it is urticarial. With the appearance of a characteristic measles rash, prodromal rashes disappear. The catarrhal period usually lasts 3 to 4 days.
The rash period begins from the 4th to 5th day of illness and usually lasts 3 days. The stages of rashes are characteristic. The first elements of the rash occur behind the ears, on the back of the nose, then during the first day it quickly spreads to the face, neck, partially to the upper chest and back. On the 2nd day, the rash covers the entire body, and on the 3rd - the upper and lower limbs. The rash is usually plentiful, bright, spotty-papular, located on unchanged skin. Sometimes it happens with a hemorrhagic component. Continuous erythema fields are formed. The body temperature on the first day of the rash is higher than in the catarrhal period (sometimes 1 to 2 days before the rash, the temperature decreases slightly; a new rise on the first day of the rash gives the temperature curve a bumpy character). The temperature remains elevated throughout the rash period. Symptoms of damage to the upper respiratory tract, eyes, intoxication become more pronounced. Changes in the nervous, urinary, cardiovascular system, gastrointestinal tract and lungs are noted. Often there are nosebleeds.
From the 4th (sometimes from the 3rd) day from the beginning of the rash, a period of pigmentation begins: the rash begins to fade, becomes brown or light brown. Pigmentation occurs in the same sequence as the rash. At the same time, catarrhal phenomena regress and intoxication decreases, the temperature normalizes, in the absence of complications, usually decreasing lytically for a short period of time or critically. The disappearance of the rash may be accompanied by small, scaly skin peeling. Sometimes, during the period of pigmentation, croup syndrome occurs due to the attachment of a secondary infection. The period of pigmentation usually lasts 1 to 1.5 weeks.
With a mild form of measles, the catarrhal period is shortened to 1-2 days, the symptoms of intoxication are weak or absent, the body temperature is subfebrile, catarrhal phenomena are insignificant, there are no spots of Velsky-Filatov-Koplik, the rash is sparse, the rash is less clear.
Complications can occur in any measles period. The most common are laryngitis , tracheitis, bronchitis , pneumonia , pleurisy . In addition, measles can be complicated by otitis media, meningitis, encephalitis, enteritis, colitis.
The diagnosis is based on an assessment of clinical and epidemiological data. In the blood at the end of the incubation and the beginning of the catarrhal period, moderate leukocytosis with neutrophilia and a left shift, lymphopenia are noted; in the period of rash - leukopenia , often with relative neutrophilia. In case of doubt in the diagnosis, they sometimes resort to specific diagnostic methods (determining the increase in antiviral antibody titers in dynamics using hemagglutination inhibition reactions, complement binding and neutralization).
A differential diagnosis in the catarrhal period is carried out with acute respiratory viral diseases. During the rash, the differential diagnosis is often carried out with rubella, scarlet fever, yersiniosis, drug dermatitis.
Most patients are treated at home. Hospitalization is required for children of the first 2 years of life, patients with severe measles, with complications, as well as patients from closed child care facilities, dormitories (according to epidemiological indications). In addition, hospitalization is necessary if it is impossible to organize patient care at home, in poor living conditions.
In the catarrhal period and the rash period, bed rest is prescribed. Good ventilation should be provided. Drink plenty of water (e.g. fruit juices, compote, tea). At elevated body temperature, it is necessary to feed the patient more often, in small portions. Food should be easily digestible, dairy and vegetable. Skin care (hygienic baths, washing, wet rubbing), the oral mucosa (drinking, especially after eating, older children and adults - rinsing the mouth after eating boiled water) is very important. An instillation in a conjunctival sac of a 10-20% solution of sulfacyl sodium is indicated, 1-2 drops 1-2 times a day.
With a painful cough, infants are given pertussin (0.5 to 1 teaspoon 3 times a day), older children and adults are prescribed non-narcotic antitussives: glaucine hydrochloride (glauvent), libexin , tusuprex, etc. In case of complications, treatment is carried out in according to their nature. In these cases, antibiotics should be prescribed in a sufficient dose and at the earliest possible time (even if complications are suspected).
The prognosis is usually favorable. However, recovery is slow. For 2 to 8 weeks or more, convalescents may experience asthenia. The transferred infection exacerbates chronic diseases, sometimes endocrine disorders occur.
Prevention The main preventive measure is the active immunization of a live weakened measles vaccine in children without measles. Of great importance are the early detection and isolation of measles patients. Disinfection in the outbreak due to the instability of the virus is not carried out; it is replaced by airing and wet cleaning. In children's institutions, groups should be accommodated taking into account their possible isolation and separation.