Viral Hepatitis B, 2005
In 2005, 42 cases of acute hepatitis B virus (HBV) infection (0.8 per 100,000) were reported, with no deaths. The age of case-patients ranged from 19 to 60 years (median, 39 years). All 42 cases were laboratory-confirmed. Thirty-six (86%) of these case-patients had clinical symptoms, and two (5%) had documented asymptomatic seroconversions. Twenty-five (60%) were residents of the Twin Cities metropolitan area, including 16 (64%) in Hennepin County and five (20%) in Ramsey County. Twenty-eight (67%) cases were male, and 21 (50%) were adolescents or young adults between 13 and 39 years of age. Twenty (48%) were white, 13 (31%) were black, four (10%) were Asian, and one (2%) was American Indian; race was unknown for four (10%) cases. One (2%) case-patient was of Hispanic ethnicity. Although the majority of cases were white, incidence rates were higher among blacks (7.6 per 100,000), Asians (2.8 per 100,000), and Hispanics (0.7 per 100,000) than among non-Hispanic whites (0.3 per 100,000).
Twenty-six (62%) of the 42 case-patients were interviewed regarding possible modes of transmission. Nineteen (73%) reported having sexual contact with one or more partners within 6 months prior to onset of symptoms, four (21%) of whom reported sexual contact with two or more partners. Of those reporting sexual activity, eight (42%) females reported only male partners, seven (37%) males reported only female partners, three (16%) males reported only male partners, and one (5%) male reported both male and female partners. Eleven (26%) case-patients reported having contact with a known carrier of hepatitis B surface antigen (HBsAg), 10 (91%) of whom reported the contact as sexual. Three (7%) case-patients reported using needles to inject drugs, one (2%) received a body piercing within 6 months prior to onset of symptoms, and two (5%) case-patients reported a recent history of blood transfusion. (A case-patient may report more than one risk factor.)
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 42 hepatitis B cases, four perinatal infections were identified in infants who tested positive for HBsAg during post-vaccination screening performed between 9 and 15 months of age. All four 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 344 infants born to HBV-infected women during 2004 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, 2005