Viral Hepatitis B, 2004

In 2004, 69 cases of acute hepatitis B virus (HBV) infection (1.4 per 100,000) were reported, with no deaths. The age of case-patients ranged from 1 to 75 years (median, 35 years). Forty-two (61%) of these case-patients had clinical symptoms; the remaining 27 had documented asymptomatic seroconversions. Thirty-seven (54%) were residents of the Twin Cities metropolitan area, including 18 (26%) in Hennepin County and 13 (19%) in Ramsey County. Forty-eight (70%) cases were male, and 36 (52%) were adolescents or young adults between 13 and 39 years of age. Forty-one (59%) were white, 16 (23%) were black, and three (4%) were Asian; race was unknown for nine (13%). Two (3%) case-patients were of Hispanic ethnicity. Although the majority of cases were white, incidence rates were higher among blacks (9.3 per 100,000), Asians (2.1 per 100,000), and Hispanics (1.4 per 100,000) than among non-Hispanic whites (1 per 100,000).

Forty-three (62%) of the 69 case-patients were interviewed regarding possible modes of transmission. Thirty-five (81%) reported having sexual contact with one or more partners within 6 months prior to onset of symptoms; 17 (49%) of whom reported sexual contact with two or more partners. Of those reporting sexual activity, 27 (77%) reported their sexual preference as heterosexual, five (14%) reported their sexual preference as homosexual, and three (9%) reported their sexual preference as bisexual. Thirteen (30%) case-patients reported having contact with a known carrier of hepatitis B surface antigen (HbsAg); 10 (77%) of whom reported the contact as sexual. Two (5%) case-patients reported using needles to inject drugs, four (9%) received a tattoo within 6 months prior to onset of symptoms, and one (2%) case-patient reported a recent history of blood transfusion.

Hepatitis B vaccine has been available since 1982, yet it continues to be underutilized in persons at greatest risk of infection. A large proportion of hepatitis B case-patients identified risk factors for sexual transmission; therefore, health care providers should discuss the need for HBV testing and vaccination with at-risk patients, including all unvaccinated adolescents, young adults, and patients seen for other sexually transmitted diseases.

In addition to the 69 hepatitis B cases, five perinatal infections were identified in infants who tested positive for HBsAg during post-vaccination screening performed at 9 to 15 months of age. Four perinatal case-patients were born in 2003 and one was born in 2002. All five 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. The infants were born in the United States and had received hepatitis B immune globulin and three doses of hepatitis B vaccine in accordance with the recommended schedule (i.e., were treatment failures). Despite these treatment failures, the success of the public health prevention program is demonstrated by the fact that an additional 791 infants born to HBV-infected women during 2002-2003 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, 2004