Clinical evaluation of oral fluid samples for diagnosis of viral hepatitis

Oral fluid samples were compared with serum samples as a specimen source for hepatitis A, B, and C virus markers. Oral fluid was obtained with a treated absorbent pad and tested by using existing commercial enzyme immunoassays with only minor modifications. Compared with serum sampling the sensitivity and specificity of oral sampling were 100% (51 of 51 samples) and 98% (46 of 47 samples) for hepatitis A virus immunoglobulin M, 100% (29 of 29 samples) and 100% (29 of 29 samples) for hepatitis B virus surface antigen, and 100% (13 of 13 samples) and 100% (13 of 13 samples) for hepatitis C virus antibody, respectively. The decline of hepatitis A virus immunoglobulin M in oral samples was parallel to, though somewhat more rapid than, that of hepatitis A virus immunoglobulin M in serum samples. It is proposed that oral sampling represents a safer and more convenient procedure for reliable hepatitis virus testing than blood sampling and that it has wide application in patient and outbreak management.