Arboviral neutralizing (N) substances appearing in avian plasmas after shooting and cardiac puncture were found sometimes to be nonspecific and at other times to be specific antibody. N substances which selectively neutralized western encephalitis (WE) and not St. Louis (SLE) or Japanese encephalitis (JE) viruses, and possibly also those that coexisted with HI substances in acetone-precipitated plasmas could be interpreted as being viral antibodies. N substances neutralizing both WE and SLE viruses were considered to be nonspecific. Neutralization of SLE or JE but not WE virus was an uninterpretable finding because this result could readily be produced by bile in plasma as well as by specific antibodies. Trauma to abdominal and thoracic viscera from shooting was probably more important in the appearance of N substances in avian plasmas than was cardiac puncture per se, since cardiac puncture of living, netted birds failed to engender appearance of N substances. Nevertheless, in birds dying or dead after shooting, it seemed likely that probing of the chest and abdominal cavities during cardiac puncture sometimes resulted in contamination of blood with bile or other body fluids containing nonspecific N substances. These findings make qualitative interpretations of results of serologic surveys of shot birds for arboviral N antibodies impossible unless each plasma with N substance is studied for specificity for the neutralized virus.
Present address: Division of Epidemiology, School of Public Health, University of California, Berkeley. This investigation was done in part during tenures of predoctoral fellowships (EF-9015, -C1 and -C2 and GPM-9015-C3) from NIAID and DGMS, and postdoctoral fellowships (EPD-9015-C4 and 5F2 A1-9015-02) from NIAID, USPHS.
Present address: Department of Microbiology, Cornell University Medical College, New York 21, N. Y. Please use this address for reprint requests.