A smaller number, perhaps 1 to 2 percent of those infected, develop liver cancer. The rest die of something unrelated. People can contract HCV from microscopic flecks of blood left on a communal straw used for snorting cocaine. The virus can linger on razors and toothbrushes. The only treatments available are the drug interferon, which often has debilitating side effects, and an anti-viral called ribavirin, recently approved for use in combination with interferon.
Treatments often manage to quell the virus, but it returns in the majority of patients.
Nor is there any vaccine for hepatitis C, as there is for the other main viral culprits in liver disease, hepatitis A and B. Chiron scientists are in the early stages of testing one vaccine candidate, but Michael Houghton, the company's top HCV expert, and one of the discoverers of the virus, cautioned against getting hopes too high. Up to 90 percent of intravenous drug users, for example, test positive for the virus. HCV infects close to half of the California state prison population. In San Francisco, the AIDS virus is still a worse health problem by far. But deaths from hepatitis C are rising while AIDS deaths are in decline throughout the United States.