Viral Hepatitis B, 2012

In 2012, 17 cases of acute hepatitis B virus (HBV) infection (0.3 per 100,000 population) were reported, with 1 death. In 2012, the case definition for acute hepatitis B was revised to include laboratory confirmed asymptomatic acute cases. Three (18%) of the 17 cases of acute hepatitis B were asymptomatic infections.

We also received 540 reports of newly identified cases of confirmed chronic HBV infection in 2012. 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 21,064 persons are estimated 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 27 to 62 years (median, 47 years). Fourteen (82%) cases were residents of the metropolitan area, including 6 (35%) in Hennepin County and 3 (18%) in Ramsey County. Thirteen (76%) cases were male and 4 (24%) were adolescents or young adults between 13 - 39 years of age. Nine (53%) were white, 5 (29%) were black, 1 (6%) was Asian, and 1 (6%) was Pacific Islander; race was unknown for 1 (6%) case. One (6%) case was known to be of Hispanic ethnicity. Incidence rates were higher among Pacific Islanders (131.1 per 100,000), blacks (1.8 per 100,000), Asians (0.5 per 100,000) and those with Hispanic ethnicity (0.4 per 100,000) than among non-Hispanic whites (0.2 per 100,000).

In addition to the 17 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 2011. 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 252 infants born to HBV-infected women during 2011 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, 2012