A salivary gland infection occurs when a bacterial or viral infection affects your salivary gland or duct. The infection can result from reduced saliva flow, which can be due to a blockage or inflammation of your salivary duct. The condition is called sialadenitis.
Saliva aids digestion, breaks down food, and works to keep your mouth clean. It washes away bacteria and food particles. It also helps control the amount of good and bad bacteria in your mouth.