Viral Hepatitis A, 2001
In 2001, 47 cases of hepatitis A (1.0 per 100,000 population) were reported. Thirty (64%) case-patients were residents of the seven-county Twin Cities metropolitan area, with 14 (30%) residing in Hennepin or Ramsey counties. Thirty-four (72%) case-patients were male. Of 46 cases for whom race was known, 39 (85%) were white, two (4%) were black, two (4%) were Asian, and three (7%) were American Indian. Although the majority of case-patients was white, incidence rates were higher among American Indians (3.7 per 100,000 population), Asians (1.2 per 100,000 population), and blacks (1 per 100,000 population) than among whites (0.9 per 100,000 population). Three case-patients (2.1 per 100,000 population) reported Hispanic ethnicity (which can be of any race). Case-patients ranged in age from 1 to 76 years; 21 (45%) cases occurred among adults 25 to 44 years of age.
In 2001, seven (15%) cases of hepatitis A were associated with a single outbreak. The outbreak which involved residents of Carver, Sibley, and Nicollet counties, began with the infection of two family members and resulted in five additional cases. Three case-patients from the index family reported recent travel to Central America. The second-generation cases were linked to either a dinner party hosted by the index family or a summer gathering that the index family attended. The third-generation cases were not linked to a specific event, but were contacts of second-generation cases.
Two (4%) cases of hepatitis A were associated with a restaurant in Kewaunee County, Wisconsin. The index case (a Wisconsin resident) was a food-handler at the restaurant who reported recent travel to Mexico. Immune globulin prophylaxis was given to 94 people, including 33 restaurant employees. Only two documented cases of hepatitis A were linked to the food-handler; both case-patients were Minnesota residents.
Of the remaining 38 sporadic cases of hepatitis A reported in 2001, a risk factor for infection was identified for 23 (61%). Thirteen (34%) cases were associated with travel, eight (62%) of whom traveled to South America or Mexico. Six (16%) case-patients had known contact with another case; six (16%) case-patients were men who had sex with men, and one (3%) case-patient had consumed raw shellfish. Four (11%) cases (all adults) were associated with child daycare settings but were not related to any known outbreaks. Young children infected with hepatitis A often are asymptomatic or experience mild illness, yet are efficient transmitters of disease. Twenty (53%) of the sporadic cases occurred among persons for whom hepatitis A vaccine is indicated; one case-patient reported both travel history and being a man who had sex with men. Persons who travel to hepatitis A endemic countries and men who have sex with men should be educated about their risk of hepatitis A and offered hepatitis A vaccine.