ASK DR. BAUGHAN                                             November 27, 1998

HEPATITIS C UPDATE

There has been considerable publicity recently regarding Hepatitis C with some confusing and alarming stories.  The Centers for Disease Control (CDC) recently published an edition of its Morbidity and Mortality Weekly Report (MMWR, October 16, 1998, Vol.47, No. RR-19) entirely devoted to prevention and control of Hepatitis C Virus (HCV) infection.

Hepatitis C is the most common chronic bloodborne infection in the U.S.  The big epidemic of HCV actually occurred in the 1980s, when there averaged 230,000 new infections each year.  Once the tests were developed to detect HCV so blood products could be screened for it, the number of new cases per year began to decline, reaching 36,000 in 1996.  Since HCV persists as a chronic disease in 85% of untreated cases, there are now an estimated 3.9 million persons infected.

HOW DO YOU CATCH IT?  Presently 60% of the new cases occur in people who repeatedly use injected street drugs.  The CDC estimates 15-20% of cases are spread through sexual contact.  Another 10% contact from job related blood exposures, kidney dialysis, or babies born to mothers with HCV.  That leaves about 10% of new cases where we cannot identify a risk factor or likely cause of infection.  Since 1992, the risk of HCV from blood transfusions or transplants is almost zero.

The sexual transmission of HCV has some curious twists.  The more partners a  person has, the higher the risk.  In single partner relationships, if the woman had HCV, the man did not seem to have any higher risk of developing HCV than men with female partners without HCV.  However, if a man was positive for HCV, the woman had 3-4 times the chance of becoming positive herself. Surprisingly, in long-term, monogamous relationships with no other risk factors, the risk of the partner catching HCV was 1.5%.

HOW IS IT DETECTED?  There are three types of blood tests to consider.  First, there is a test to see if the body has made an antibody to HCV.  This can determine if the person was ever exposed to Hepatitis C, but not if the infection is active or cured.  Next are tests that check for the  virus itself, detecting parts of the virus’s RNA.  These tests are called the PCR assays.  They might be reported positive or negative, or they might try to estimate the number of viruses present.  These tests are still being refined and at present do not have FDA approval.  Blood tests of liver enzymes (ALT or SGOT) can determine if the liver is actively inflamed.  One sneaky aspect of this virus, though, is that liver damage can sometimes occur even when the liver enzymes are normal.  For that reason, a liver biopsy is sometimes recommended to determine if liver damage is occurring.

WHO SHOULD BE TREATED?  Much research is being directed at this question.  Since 15-20% of people will clear the virus without treatment, early treatment is not always necessary.  But how long should we wait before starting treatment?  Should we wait until there is some evidence of inflammation or damage?  When is the treatment worse than the disease?  Multiple research protocols are being conducted because definitive answers are not yet clear.  Interferon treatments have resulted in 15-25% remission rates.  Interferon combined with ribavirin has shown 40-50% prolonged response rates.

WHO SHOULD BE SCREENED?  The CDC did not recommend screening except for high-risk groups (IV drug users, multiple sexual partners, job related blood contact, transfusions or transplants before 1992, mother with HCV) and “anyone who wishes to know. . .”  The report also states, “HCV is not spread by sneezing, hugging, coughing, food or water, sharing eating utensils or drinking glasses, or casual contact.  Persons should not be excluded from work, school, play, childcare or other settings on the basis of their HCV infection status.”