Hepatitis A is a viral infection of the liver transmitted most commonly by fecal-oral contact through contaminated food or water or from person-to-person via contaminated hands or oral-anal contact. Hepatitis A virus primarily infects humans.

There were 101 cases of hepatitis A reported in Indiana in 2001, for a rate of 1.7 cases per 100,000 population. This represents a 31% decrease over the previous year. In addition, the incidence remained below the average incidence of the years 1997-2000 of 180 cases (Figure HpA1). The number of reported cases was highest during the late winter and summer months (Figure HpA2).

Age-specific rates were highest among adults ages 50-59 (2.4), adults ages 30-39 years (2.3) and children ages 5-9 (2.3) (Figure HpA3). The sex-specific rate for males (2.2) is twice as high as that for females (1.1). Race-specific rates were higher for whites (1.5) than for blacks (0.8).  Of those counties that had five or more cases reported, Hamilton County had the highest incidence rate (7.1).  The number of reported cases for Indiana counties can be found in Table HpA1.

The most commonly reported risk factor for hepatitis A infection was contact with a known case. Approximately 35% of the interviewed cases reported prior contact with a case, most commonly through household or sexual contact. Other common risk factors included male homosexual/bisexual contact (22%) and international travel (22%). Eight (8%) of the interviewed cases were employed as foodhandlers during their infections. The reported risk factor data are summarized in Table HpA2.

There were no outbreaks of hepatitis A infection reported in Indiana in 2001. Two cases (1.0%) were linked to an outbreak in Michigan.