Pertussis is an acute respiratory infection caused by the bacterium Bordetella pertussis. It is common in infants and young children. It is characterized clinically by paroxysmal spasmodic cough and cockle-like inspiratory roar. The course of the disease can be as long as 2 to 3 months, hence the name pertussis. The incubation period is 2 to 20 days, usually 7 to 10 days. The typical course is divided into three phases: (a) Catarrhal phase (prodromal phase) From the onset of the disease to the appearance of spasmodic cough, about 7 to 10 days. The initial symptoms are similar to those of general upper respiratory tract infections, including low fever, cough, runny nose, sneezing, etc. Other symptoms improve after 3 to 4 days, while the cough worsens. This period is the most contagious and has the best treatment effect. (B) Spasmodic coughing stage The cough changes from a mono-cough to a paroxysmal cough, with more than ten to dozens of short coughs in a row, followed by a deep and long inhalation, followed by a chicken-like roar because the vocal cords are still contracted, followed by a series of paroxysmal coughs, and so on, until the cough produces sticky sputum or spits out stomach contents. Each paroxysmal cough can last for several minutes and can be as many as ten to dozens of times a day, with lighter days and heavier nights. This period is as short as 1 to 2 weeks. The longer period can be up to 2 months. (C) Recovery period: The paroxysmal spasmodic cough gradually decreases to stop, and the chicken-like roar disappears. This period is usually 2 to 3 weeks. If there are complications, it can take up to several months. Treatment (a) General and symptomatic treatment. For heavy cough, dormant or non-natural root can be used at bedtime to facilitate sleep and reduce paroxysmal cough. For thick sputum, expectorants or nebulized inhalation can be given. In severe cases, adrenal corticosteroids may be given to reduce inflammation. (ii) Antibiotic treatment. Antibiotics applied within 4 days of the khat phase can shorten the coughing period or block the occurrence of spasmodic cough. after 4 days or during the spasmodic coughing period can shorten the elimination period and prevent secondary infection, but cannot shorten the course of the disease. Prefer erythromycin 30-50mg/kg/day for 7-10 days. Chloramphenicol (same dose as above), or cotrimoxazole, ampicillin, etc. are also available.