Viral Hepatitis B, 2011

In 2011, 20 cases of symptomatic acute hepatitis B virus (HBV) infection (0.4 per 100,000 population) were reported, with no deaths. In addition to these cases, 1 individual with documented asymptomatic seroconversion was reported.

We also received 689 reports of newly identified cases of confirmed chronic HBV infection in 2011. 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 20,216 persons are assumed to be alive and living in Minnesota with chronic HBV. The median age of chronic HBV cases in Minnesota is 42 years.

Acute cases ranged in age from 18 to 59 years (median, 45 years). Fourteen (70%) cases were residents of the metropolitan area, including 5 (25%) in Hennepin County and 5 (25%) in Ramsey County. Fifteen (75%) cases were male and 6 (30%) were adolescents or young adults between 13 and 39 years of age. Six (30%) were black, 4 (20%) were white, 1 (5%) was Asian, and 1 (5%) was multi-racial; race was unknown for 8 (40%) cases. No case was known to be of Hispanic ethnicity. Incidence rates were higher among blacks (2.0 per 100,000) and Asians (0.4 per 100,000) than among non-Hispanic whites (0.1 per 100,000).

In addition to the 20 hepatitis B cases, 1 perinatal infection was identified in an infant who tested positive for HBsAg during post-vaccination screening performed between 9 and 15 months of age. The perinatal case was born in 2010. The perinatal infection occurred in an infant identified through a public health program that works to ensure appropriate prophylactic treatment of infants born to HBV-infected mothers. The infected infant was 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 was therefore considered a treatment failure. Despite this failure, the success of the public health prevention program is demonstrated by the fact that an additional 357 infants born to HBV-infected women during 2010 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, 2011