The spinal fluid of acute hepatitis B patients--an occupational hazard?

Spinal fluid and serum samples from 19 patients, with acute viral hepatitis, type B, already known to have HBs antigenemia, were tested for the detection of HBsAg by two techniques; Hemagglutination Inhibition (H.I.) and Enzyme Linked Immuno Sorbent assay (ELISA). HBsAg was detected in all serum samples by both techniques while all spinal fluid samples were free of that antigen except one sample that was found to contain HBsAg by the ELISA technique only. This sample was also proved to contain occult blood as shown by the positive benzidine reaction.