2002 Oregon CD Statistics: Hepatitis B (acute)

Hepatitis B is a vaccine-preventable viral disease of the liver that occurs when the virus of an infected person passes (through blood, semen, or saliva) into the blood stream of a non-immune person. Percutaneous or permucosal exposures take place when hypodermic needles are shared, when blood splashes into an eye, during sex, by biting, when improperly sterilized injection devices are used for tatooing, body piercing, and acupuncture, and when the baby of a hepatitis B carrier is being born. Acute hepatitis B virus infection (diagnosed by the seropresence of the IgM antibody to the hepatitis B surface antigen [IgM anti- HbsAg]) usually, but not always, causes jaundice. Some infections are mild, even asymptomatic, and may go undetected.

Acute hepatitis B in Oregon declined from 1993 through 1996 ? the very end of a decade-long, 72% decline that started here after the hepatitis B vaccine was liscensed in 1982 (hepatitis B declined 76% in the US as a whole over the same period of time). The number of cases leveled off in 1997, to about 125 cases per year, except for case-count spikes in 1998 and 2001. An excess number of cases in Lane County (Eugene) accounted for more than half of the case-count spike in 1998 ? most of the extra cases were IV drug users. In 2001, four counties (Jackson, Lane, Marion, and Multnomah) accounted for the case-count spike and, again, most of the extra cases were IV drug users. Other interesting details in the figures include high incidence among 30?39 year-old men and the fact that Oregon incidence rate of acute hepatitis B is higher than the incidence rate in the US as a whole (the reasons for this are unclear).