Bronchitis itself is not contagious, but the viruses and bacteria that cause bronchitis are contagious. Acute bronchitis is most often caused by viruses such as those causing colds, flu, COVID-19, or RSV. These viruses spread mainly through respiratory droplets when an infected person coughs, sneezes, or talks, and sometimes by touching contaminated surfaces and then touching the face. People with acute bronchitis can be contagious for a few days to about a week, especially at the onset of symptoms. Chronic bronchitis, which is a longer-term inflammation usually caused by irritants like smoking, is generally not contagious.
