Hepatitis A is a virus that infects the liver and is commonly spread through contaminated food or water. It is most prevalent in Central and South America, Asia, and Mexico. The virus reproduces in human cells and is able to spread to others if infected individuals come into contact with objects before symptoms appear. The hepatitis A virus can be prevented through vaccination which proved effective during a 2013 outbreak in California. Infected individuals may experience jaundice, fever, and stomach pains as the immune system works to eliminate the virus with the help of B and T cells.