Chickenpox is contagious for about a week before and after the onset of the disease. This contagious period is about 10 days in immunocompetent people. The infectious period is determined by the route of transmission of chickenpox. The chickenpox virus is mainly found in the upper respiratory tract and herpes fluid of the patient, so its transmission is mainly through the upper respiratory tract, or direct contact with the vesicular fluid of herpes, as well as the clothing and utensils contaminated by herpes fluid to spread. Therefore, before the rash comes out, the transmission of chickenpox mainly relies on droplet transmission from the upper respiratory tract; after the herpes comes out, the herpes fluid contains a large amount of virus, which can be transmitted through direct contact. It takes about 10 days from the onset of the disease until the rash subsides, and the infection period can be longer in patients who are immunocompromised or have underlying diseases.