Bronchitis itself isn’t contagious, but some of its causes are. If your bronchitis is caused by a virus, you can be contagious for a few days to a week. If your bronchitis is caused by bacteria, you usually stop being contagious 24 hours after starting antibiotics. Other causes of bronchitis aren’t contagious.
If you have acute bronchitis, whether it’s viral or bacterial, you should stay home from work because acute bronchitis is contagious and can transmit to others. Bronchitis is an inflammation and irritation of the bronchi in the lungs that causes a cough.