Viral Hepatitis B, 2010

In 2010, 24 cases of symptomatic acute hepatitis B virus (HBV) infection (0.5 per 100,000 population) were reported, with no deaths. In addition to these cases, 5 individuals with documented asymptomatic seroconversion were reported. Prior to 2006, both symptomatic cases and asymptomatic seroconvertors were counted as incident cases. This change in case counting criteria should be considered when examining case incidence trends.

MDH also received 623 reports of newly identified cases of confirmed chronic HBV infection in 2009. Prior to 2009, confirmed and probable chronic cases were reported in the year in which they were first reported. Beginning in 2009, only confirmed cases are reported, and cases are reported in the year in which case-confirming data are available. A total of 19,420 persons are assumed to be alive and living in Minnesota with chronic HBV. The median age of chronic HBV cases in Minnesota is 42.

The 24 acute cases ranged in age from 28 to 79 years (median, 42 years). Twelve (50%) of the 24 cases were residents of the metropolitan area, including 8 (33%) in Hennepin County and 2 (8%) in Ramsey County. Sixteen (67%) cases were male and 9 (38%) were adolescents or young adults between 13 and 39 years of age. Thirteen (54%) were white, 3 (13%) were black, 2 (8%) were American Indian, 1 (4%) was Asian, and 1 (4%) was of other race; race was unknown for 4 (17%) cases. No case was known to be of Hispanic ethnicity. Although the majority of cases were white, incidence rates were higher among blacks (1.2 per 100,000) and American Indians (3.1 per 100,000) than among non-Hispanic whites (0.3 per 100,000).

In addition to the 24 hepatitis B cases, 5 perinatal infections were identified in infants who tested positive for HBsAg during post-vaccination screening performed between 9 and 15 months of age. The perinatal cases were born in 2009. The perinatal infections occurred in infants identified through a public health program that works to ensure appropriate prophylactic treatment of infants born to HBV-infected mothers. All four infants were born in the United States and had received hepatitis B immune globulin and 3 doses of hepatitis B vaccine in accordance with the recommended schedule and were therefore considered treatment failures. Despite these treatment failures, the success of the public health prevention program is demonstrated by the fact that an additional 406 infants born to HBV-infected women during 2009 had post-serologic testing demonstrating no infection.

• For up to date information see>> Hepatitis B
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2010