Common causes of chills include bacterial or viral gastroenteritis, influenza, meningitis, sinusitis and pneumonia. Other causes of chills are strep throat, malaria and urinary tract infections, according to Healthline.
Viral gastroenteritis is more commonly known as the stomach flu. In addition to sudden chills, symptoms of this condition include watery diarrhea, abdominal cramps, nausea or vomiting, states Mayo Clinic. This stomach flu is caused by noroviruses and rotavirus. Noroviruses are the most common cause of food-borne sickness as of 2015. Children and adults are susceptible to this sickness, and it is especially contagious among people who share small spaces.
Rotavirus is more common among children and young infants. This virus is known to infect children when they put something in their mouths that was contaminated by the virus, explains Mayo Clinic. Adults who have this virus may not exhibit any symptoms, but it is still contagious. Vaccines for this virus are available in the United States and several other countries.
Bacterial gastroenteritis is caused by a bacterial infection in the gut. Causes of this type of infection include bad hygiene and contaminated food or water, says Healthline. People with weak immune systems are more susceptible to this kind of infection. The incorrect handling of food also increases the risk factor for bacterial gastroenteritis.