The measles is an acute infectious disease of viral etiology with an airborne mechanism of transmission characterized by fever, catarrhal inflammation 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 and ultraviolet radiation.
The source of the pathogen is measles sick person. It is contagious to others from the last 1-2 days of the incubation period to the 4th day after the appearance of the rash. Transmission of the pathogen occurs through airborne droplets. The virus enters the air with droplets of exudate from the patient’s upper respiratory tract during a conversation, cough, sneeze. Infection occurs both during direct communication with the patient and at a considerable distance from him, since the virus with air flow can penetrate into neighboring rooms and even into other floors. If a pregnant woman gets measles before giving birth, a transplacental infection of the fetus is possible. In this case, the newborn has symptoms of measles. The pathogen is not transmitted through a third party; cases of its transmission through household items due to the low persistence of the virus are very rare.
When the causative agent of measles is brought to certain areas where it has not been for many years, as well as to unvaccinated children's groups, almost everyone who has not had measles, regardless of age, gets sick. In large settlements, where migratory processes are expressed, children at the age of 1–7 years more often become ill, in the age groups older than 7 years, the incidence decreases rapidly and after the age of 14 years there are only individual cases of measles. For measles, as for all airborne infections, seasonality is characteristic. The maximum number of diseases is recorded from December to May, the minimum - in August — September. Due to mass vaccination against measles, the incidence of it has dropped dramatically.
Clinical picture . The incubation period ranges 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 there are 3 periods: catarrhal (initial, prodromal), period of rash and pigmentation. The catarrhal period begins acutely: a runny nose, cough , conjunctivitis , symptoms of intoxication appear (increase in body temperature to 38 - 39 ° C, headache , indisposition, lethargy, loss of appetite, etc.). Cough usually rough, barking, hoarse voice. Croup syndrome may develop. Face becomes puffy, eyelids and lips swell. Conjunctival hyperemia and sclera, tearing and photophobia are noted. From the 2nd — 3rd day on the mucous membrane of the hard and soft palate red spots (enanthema) are found. 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 appear (0.5-1 mm in diameter), which have a grayish-white color, rise above the surface of the mucous membrane, surrounded by a rim of hyperemia. Papules do not merge with each other, are firmly soldered to the underlying tissue (not removed with a spatula). These elements are a specific symptom of measles and are called the spots of Velsky — Filatov — Koplik. They persist 2 - 4 days and disappear on the first, less often the second day of the rash period. After their disappearance, the buccal mucosa remains hyperemic and rough for several days. Sometimes in the catarrhal period, a mild punctate scarlet-like or spotted rash is found on the skin, in some cases it can be urtikarny. With the appearance of the characteristic measles rash, the prodromal eruptions disappear. Catarrhal period usually lasts 3 - 4 days.
The period of rash starts from the 4-5th day of the disease and usually lasts 3 days. Characteristic phased eruptions. The first elements of the rash appear behind the ears, on the back of the nose, then during the first days it quickly spreads to the face, neck, and partly to the upper chest and back. On the 2nd day, the rash covers the entire body, and on the 3rd - upper and lower extremities. The rash is usually profuse, bright, maculopapular, located on the unchanged skin. Sometimes it happens with a hemorrhagic component. Mostly formed solid fields of erythema. The body temperature on the first day of the rash is higher than in the catarrhal period (sometimes the temperature drops a little 1 to 2 days before the rash; a new rise on the first day of the rash gives the temperature a two-humped character). The temperature remains elevated during the entire period of the rash. Symptoms of lesions of 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 onset 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 in the absence of complications normalizes, decreasing usually lytically for a short period of time or critically. The disappearance of the rash may be accompanied by a small, scaly, flaky skin. Sometimes in the pigmentation period, croup syndrome occurs, due to the addition of a secondary infection. The pigmentation period usually lasts 1 to 1.5 weeks.
In the light form of measles, the catarrhal period is shortened to 1-2 days, intoxication symptoms are mild or absent, body temperature is low-grade, minor catarrhal phenomena, Velsky — Filatov — Koplika spots may not be present, the rash is scant, the eruption stage is less distinct.
Complications can occur in any period of measles. The most common laryngitis , tracheitis, bronchitis , pneumonia , pleurisy . In addition, measles can be complicated by otitis, meningitis, encephalitis, enteritis, colitis.
The diagnosis is based on the 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 shift to the left, lymphopenia; in the period of rash - leukopenia , often with relative neutrophilia. When in doubt, a diagnosis is sometimes resorted to specific diagnostic methods (determination of an increase in antiviral antibody titres over time using hemagglutination inhibition reactions, complement fixation and neutralization).
Differential diagnosis in the catarrhal period is carried out with acute respiratory viral diseases. In the period of rash differential diagnosis is often carried out with rubella, scarlet fever, yersiniosis, medical dermatitis.
Most patients are treated at home. Children of the first 2 years of life, patients with severe measles, with complications, as well as patients from closed children's institutions, hostels (according to epidemiological indications) are subject to hospitalization. In addition, hospitalization is necessary if it is impossible to organize the care of the patient at home, and in poor living conditions.
In the catarrhal period and the period of rash prescribed bed rest. Ensure good ventilation of the room. Recommend abundant drinking (for example, 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, milk-vegetable. Skin care (hygienic baths, washing, wet wiping), oral mucosa (drinking, especially after eating, older children and adults - rinsing the mouth after eating boiled water) is very important. Shown instillation into the conjunctival sac of a 10–20% solution of sulfacyl-sodium, 1-2 drops, 1–2 times a day.
With a painful cough, young children are given pertussin (0.5-1 teaspoon 3 times a day), older children and adults are prescribed non-narcotic antitussives: glaucine hydrochloride (glaulent), libexin , tusuprex, etc. For complications, the treatment is carried out according to their character. In these cases, it is necessary to prescribe antibiotics 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, asthenia may be observed in convalescents. The transferred infection contributes to the exacerbation of chronic diseases, sometimes endocrine disorders occur.
Prevention. The main preventive measure is active immunization of live measles vaccine, which has been weakened by measles vaccine. Early detection and isolation of patients with measles are of great importance. 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 placed taking into account their possible isolation and separation.