Viral Hepatitis A, 2005

In 2005, 36 cases of hepatitis A (0.7 per 100,000 population) were reported. Twenty-seven (75%) case-patients were residents of the Twin Cities metropolitan area, including 15 (56%) residents of Hennepin or Ramsey Counties. Thirty-one (86%) of the cases were male. Case-patients ranged in age from 3 to 66 years (median age, 25 years). Race was reported for 25 (69%) cases, of whom 20 (80%) were white, 4 (16%) were black, and one (4%) was of unknown race. No cases have been reported in American Indians since 2002. The incidence rate of hepatitis A in American Indians declined steadily from 10.4 per 100,000 population in 1999 to 6.0, 3.7, and 2.5 per 100,000, respectively, in 2000, 2001, and 2002 demonstrating the success of targeted immunization efforts initiated in 1999. Hispanic ethnicity was reported for eight cases (5.6 per 100,000).

One (3%) case-patient was an employee of a food-serving establishment. No community transmission of hepatitis A was identified.

Of the 36 cases, a risk factor was identified for 27 (75%). Seven (26%) had known exposure to a confirmed hepatitis A case. Four of these persons, in two separate households, became infected following exposure to a close contact, representing missed opportunities to administer immune globulin. Two cases were household contacts of two children in the same household who were adopted from Liberia. One case was a close contact of a foreign-born, adopted child.

Of the remaining 20 (74%) cases with a risk factor identified, 19 (95%) were associated with travel. Of these 19, 13 (68%) traveled to Mexico or South America, two of whom reported consuming raw shellfish. One additional case with no travel history reported consuming raw shellfish. Nine (25%) cases did not report any known exposure or risk factors; however, two had contact with a household member enrolled in a childcare center. Young children infected with hepatitis A are often asymptomatic or have mild illness, but are efficient transmitters of disease.

• For up to date information see>> Hepatitis A
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2005