Viral Hepatitis C, 2001
In 2001, 31 cases of acute hepatitis C virus (HCV) infection were reported. Twenty of these cases had clinical symptoms, and eleven were asymptomatic seroconversions. Eleven (35%) case-patients were residents of the seven-county Twin Cities metropolitan area, and 20 (65%) case-patients resided in greater Minnesota. The median age among case-patients was 30 years (range, 18 to 53 years). Fifty-two percent of case-patients were female. Eighteen (58%) case-patients were white, eight (26%) were American Indian, three (10%) were black, and race was unreported for two (6%) case-patients of Hispanic ethnicity. Although the majority of case-patients were white, incidence rates were higher among American Indians (9.9 per 100,000 population), blacks (1.5 per 100,000 population) and Hispanics (1.4 per 100,000 population) than among whites (0.4 per 100,000 population).
Among the 31 case-patients, 17 (55%) reported using needles to inject drugs. A cluster investigation of eight cases among injecting drug users was initiated after three cases were identified through routine testing of plasma donors. Initiation of injecting drug use had occurred within 6 months of symptom onset or asymptomatic seroconversion. These eight cases occurred among young adults 18 to 32 years of age residing in Hennepin County or northern Minnesota.
Four (13%) of the remaining case-patients had sexual contact with a known anti-HCV positive partner within 6 months prior to onset of symptoms, and two (6%) case-patients identified occupational exposures. No risk factor was determined for eight (26%) cases.
More than 2,600 reports of newly identified anti-HCV positive persons, most of whom are chronically infected, were reported to MDH in 2001. The 31 acute cases represent 1% of those recently diagnosed. Since most cases are asymptomatic, medical providers are encouraged to review patients' risk factors for HCV infection to determine the need for testing. Persons who test positive for HCV should be screened for susceptibility to hepatitis A and hepatitis B and immunized appropriately.