What does RIBA stand for?

Although adopting an S/CO ratio as a criterion for referring for further testing by recombinant immunoblot assay (RIBA) has been advocated by some groups (3), our data show that this criterion may be misleading and would deny a confirmatory diagnosis by giving false-negative results for many persons.

For this investigation, a person was defined as having health-care-associated acute hepatitis C if he or she 1) had symptoms of acute hepatitis within 6 months of having a procedure performed at clinic A during July-December 2007; 2) had laboratory-confirmed HCV infection (antibodies to HCV [anti-HCV]) by enzyme immunoassay (EIA) and recombinant immunoblot assay (RIBA) or EIA with an appropriate signal-to-cutoff ratio for a given assay, or presence of HCV RNA by polymerase chain reaction (PCR) in the absence of acute hepatitis A virus (HAV); and 3) did not have other risks for HCV infection.

1) Positive screens that have a low signal-to-cutoff ratio will be automatically reflexed to a recombinant immunoblot assay, or RIBA, confirmatory test before reporting the antibody screen.