Magnitude, kinetics, and duration of vibriocidal antibody responses in north americans after ingestion of vibrio cholerae

Sera from 147 volunteers were examined for vibriocidal antibody by the tube-dilution method before and after they ingested 103-106 Vibrio cholerae organisms. Titers increased significantly after challenge in 97070 of 110 persons who excreted V. cholerae. In 12070 of the bacteriologically confirmed infections, the titer increased significantly only to the homologous (Inaba or Ogawa) serotype. Levels of vibriocidal antibody decreased substantially between one and six months after challenge, but they usually remained elevated over base-line values. Levels of antitoxin to V. cholerae were measured by IgG enzyme-linked immunosorbent assay (ELISA), rabbit skin permeability tests, and adrenal cell techniques in 73 pairs of prechallenge and postchallenge sera. Results of thevibriocidal assay agreed most closely with those of the ELISA, the most sensitive antitoxin assay, in serologically detecting clinical and subclinical infections. Recent infection could be accurately serodiagnosed by levels of vibriocidal antibody and antitoxin (by IgG ELISA) in a convalescent-phase serum.