Hepatitis A infection is caused by the hepatitis A virus. Hepatitis A virus is passed in the stool of infected persons. Unlike many other viruses, it can survive for a long time at room temperature in food and on surfaces and objects. The virus is not affected by cold or by freezing, but it is inactivated by heating foods to >185o F (85o C) for one minute. Adequate chlorination of water also kills the hepatitis A virus.