I. Symptoms The incubation period is generally 10 days, and can be as short as 6 days for severe infections or infections obtained through blood transfusions, and up to 3-4 weeks for those who have received immunization preparations (whole blood, serum, immunoglobulin, etc.) or have been vaccinated against measles. The main clinical manifestations of this period are: measles virus can be excreted from upper respiratory secretions at the end of the incubation period for 1 to 2 days. Some patients may have temporary mild upper respiratory symptoms and low-grade fever, or even a transient rash, a few hours after exposure to measles patients, but this is rare. Second, the typical course of measles can be divided into three stages: prodromal period, rash period and recovery period 1, prodromal period: generally lasts 3 to 5 days, while those who have been vaccinated against measles or have passive immunity can be as short as 1 day. Clinical manifestations during this period: physical examination reveals marked mucosal congestion in the oral cavity and pharynx, khat symptoms of inflammation of the upper respiratory tract (including ocular conjunctiva), often accompanied by gastrointestinal symptoms such as decreased appetite and even vomiting and diarrhea. There is fever, cough, runny nose, watery eyes, photophobia, etc., accompanied by varying degrees of general discomfort. Fever is often low day and high night, rising day by day to 39-40℃. Older children or adults often complain of headache, dizziness, weakness and drowsiness. Younger children even have shortness of breath and difficulty. Two to three days after the onset of the disease can appear on the buccal mucosa opposite the first molar Koch’s spot, a characteristic sign of the prodromal phase of measles, has early diagnostic value of measles. This tiny intraoral rash, white, pinpoint size, scattered on the bright red moist buccal mucosa. Initially only a few, soon increased, and can fuse, spreading to the entire buccal mucosa, as well as the inner lips, gums and other places, but also occasionally seen on the eyelid conjunctiva, rarely occurring in the hard and soft palate. When the number of spots is small, it is easy to see tiny white spots in sunlight with a surrounding red halo. Individual patients see a rubella-like or scarlet fever-like or urticaria-like rash on the neck, chest and abdomen at the beginning of the prodromal phase, which subsides within a few hours and is called a prodromal rash. Sometimes brownish-red spots can be found on the palatal lobe (also known as the uvula), tonsils, posterior pharyngeal wall, and soft palate, which quickly fade away at the beginning of the rash period. 2.Rash phase: Rash: The rash begins to appear 3 to 5 days after the onset of the disease when it reaches its peak, often 1 to 2 days after seeing the Koch’s spot. The rash first appears from the hairline behind the ear, then gradually spreads to the forehead, face and neck of the head, and from top to bottom to the chest, abdomen and back, and finally to the extremities and the soles of the hands and feet, spreading to the whole body in 2-3 days. The rash is mainly a maculopapular rash, which is bright red at the beginning and fades when pressed, varying in size, with an average diameter of 2 to 5 mm and sparse distribution. Symptoms of other organ lesions: When the disease is severe, especially when accompanied by cardiopulmonary failure, the color of the rash may suddenly turn dark and fade quickly. With the peak of the rash, the symptoms of systemic toxicity are aggravated, the body temperature is further increased, up to 40℃ or more, mental depression, drowsiness and lethargy, or restlessness all day long, cough with increased sputum, dry lips and tongue, extreme congestion of the pharynx, puffy eyelids, and more secretions. The lymph nodes in the neck and the liver and spleen are enlarged, and the lungs often smell dry and wet woven grass. The rash period is often more severe in adults than in children, and the rash is also dense, but the number of concurrent bacterial infections seems to be less than in infants. 3, the recovery period: If there are no complications, simple measles from the onset of the rash to the general course of the rash is 10 to 14 days. 3, transmission and vaccination: currently in the season of influenza, measles and other respiratory infectious diseases, measles is transmitted through the respiratory tract, to maintain good personal hygiene habits, keep the indoor air circulation; school public places should be regularly open windows and ventilation, free measles vaccination can effectively prevent measles disease. Measles immunization program: three doses for 8 months, 18 months and 6 weeks of age; those with less than three doses should be replanted to complete three doses.