How long is bronchitis contagious? coworker has it, was sick monday and i saw her today (saturday.) still infectious? she is also a smoker (im not)

Varies: Acute bronchitis is very common and is generally caused by a contagious virus. The symptoms usually improve in about a week to 10 days but sometimes last 3 weeks or longer. Chronic bronchitis, which is a more serious condition, is a constant irritation or inflammation of the lining of the bronchial tubes, which is often due to smoking. However, coughing at anytime could spread infectious agents.