Campylobacter is the second most common cause of foodborne illness in the United States after Salmonella. Over 3,000 cases were reported to the Centers for Disease Control and Prevention in 2003, or 12.6 cases for each 100,000 persons in the population. Many more cases go undiagnosed and unreported, with estimates as high as 2 to 4 million cases per year. It is estimated that each case costs $920 on average due to medical and productivity (lost wages) expenses with an annual total cost of $1.2 billion.