Medical Health Encyclopedia

Some of these tests can pinpoint hepatitis antigens directly. These tests, however, have limitations:

• There may not be sufficient numbers of antibodies to be detectable by blood tests for up to weeks or months after hepatitis develops. Blood tests that are taken too early, then, may miss these signs of infection.
• Antibodies also persist after patients recover, so a positive antibody test can indicate a previous infection but does not necessarily determine if the infection is active.

The assays for individual hepatitis viruses may differ.

Polymerase Chain Reaction. In some cases of hepatitis C, a polymerase chain reaction (PCR), may be performed. A PCR is able to make multiple copies of the genetic material (the RNA) of the virus to the point where it is detectable.

Text Continues Below

---

Screening for HCV. In the March 16, 2004 issue of the Annals of Internal Medicine, the U.S. Preventive Services Task Force recommended against routine screening for the HCV infection in the general population due to low prevalence of the disease. In addition, it "found no evidence that screening for HCV infection in adults at high risk leads to improved long-term health outcomes" and found insufficient evidence to recommend for or against such screening. However, the Task Force did advise testing in those with signs or symptoms of liver disease. The failure to recommend testing in the high-risk population goes against current recommendations made by CDC, NIH and other professional organizations. In response to the study, The American Association for the Study of Liver Diseases issued a statement saying that halting such screening would be a "terrible mistake with grave consequences," pointing out that the study itself underscored some key infection-related data which strongly emphasizes the need for screening in high-risk populations.

Biopsy