Evaluation of the solid-phase radioimmunoassay for diagnosis of St. Louis encephalitis infection in humans.

Since the use of highly purified viral proteins in the solid-phase radioimmunoassay (SPRIA) procedure is not practical for routine diagnostic serology, the procedure was adapted for use with the crude antigens now commonly used to diagnose St. Louis encephalitis (SLE) virus infections. SLE and various other alpha- and flavivirus antigens were tested by both the SPRIA procedure and conventional serological methods. Standards were established for use of the crude antigens in the SPRIA procedure. Reproducibility of the procedure was similar to that of conventional tests. The SPRIA procedure specifically differentiated SLE from clinically similar alphaviruses, but did not differentiate SLE from related flaviviruses very well. SPRIA diagnosis of SLE infections by the immunoglobulin G response in paired sera was good. Generally, the crude antigen SPRIA procedure was as sensitive as the conventional serological tests, but not as specific.

Empleo de técnicas de radioinmunoensayo en fase sólida para el diagnóstico serológico de la peste infecciosa humana / The use of solid-phase radioimmunoassay techniques for serodiagnosis of human plague infection

Los resultados de las pruebas de radioinmunoensayo en fase sólida llevadas a cabo con sueros sanguíneos de casos confirmados y sospechosos de peste infecciosa humana indican que estos ensayos pueden aportar valiosos beneficios al diagnóstico de esa enfermedad (AU)

Empleo de tecnicas de raioinmunoensayo en fase solida para el diagnostico serologico de la peste infecciosa humana. / Use of solid-phase radioinmunoassay techinics for serodiagnosis of human plague infection

Se han empleado tecnicas de radioinmunoensayo en fase solida (RIEFS) para estudiar las concentraciones de los anticuerpos IgM e IgG contra la fraccion purificada 1A de Yersinia pestis en varios sueros sanguineos humanos.Los resultados se han comparado con los datos obtnidos al utilizar el ensayo normalizado de hemaglutinacion pasiva (HAP) que recomienda el Comite de Expertos en Peste de la Organizacion Mundial de la Salud. Estos resultados indican que el empleo del RIEFS puede ayudar a que se conserve la fraccion antigenica 1A, que no es posible obtener en el comercio.Ademas, es aparente que algunos casos de peste infecciosa humana, que no muestran titulaciones significativas de HAP ni aumentos en estas titulaciones, se pueden diagnosticar mediante el uso apropiado del RIEFS

Plague in Central Java, Indonesia.

Plague in man occurred from 1968 to 1970 in mountain villages of the Boyolali Regency in Central Java. Infected fleas, infected rats, and seropositive rats were collected in villages with human plague cases. Subsequent isolations of Yersinia pestis and seropositive rodents, detected during investigations of rodent plague undertaken by the Government of Indonesia and the WHO, attested to the persistence of plague in the region from 1972 to 1974.Since 1968, the incidence of both rodent and human plague has been greatest from December to May at elevations over 1000 m. Isolations of Y. pestis were obtained from the fleas Xenopsylla cheopis and Stivalius cognatus and the rats Rattus rattus diardii and R. exulans ephippium. The major risk to man has been fleas infected with Y. pestis of unique electrophoretic phenotype. Infected fleas were collected most often in houses.Introduced in 1920, rodent plague had persisted in the Boyolali Regency for at least 54 years. The recent data support specific requirements for continued plague surveillance.

Delayed-type hypersensitivity responses in mice infected with St. Louis encephalitis virus: kinetics of the response and effects of immunoregulatory agents.

Labeled monocyte infiltration techniques have been used to study delayed-type hypersensitivity responses in mice immunized with St. Louis encephalitis virus. A delayed 24- to 48-h inflammatory response occurred 6 to 7 days after immunization. This response can be potentiated by cyclophosphamide treatment, by BCG administration, or by splenectomy. Treatments known to selectivity inhibit T-cell function suppressed the response.

Use of glutaraldehyde-fixed goose erythrocytes in arbovirus serology.

Goose erythrocytes preserved with glutaraldehyde were compared with fresh cells in hemagglutination and hemagglutination-inhibition tests for arbovirus antigens and antibodies. The glutaraldehyde-fixed cells were as sensitive and specific as theresh erythrocytes and were stable at 4 degrees C for 6 months.

The serological response to Yersinia pestis infection.

Passive haemagglutination antibody titres to Fraction I antigen of Yersinia pestis were plotted against day of clinical illness in 82 patients in Viet Nam. A rise was evident by day 5 with a peak at day 14, after which a plateau occurred. In contrast to all other patients, 2 patients with recurrent infections had elevated titres at the time of admission which decreased significantly during convalescence.

Production of antibody in induced granulomas.

A method of producing antibodies in artificially induced granulomas with various microbial antigens is examined.

Serologic observations during an outbreak of rat borne plague in the San Francisco Bay area of California.

Results of a serologic study of a plaque outbreak among rats (Rattus norvegicus) and associated wild rodents are presented. Bacteriologic and serologic evidence points toward mutual exchange of fleas and plaque infection between the intermingled rat and wild rodent populations. Results emphasize the value of serologic methods for epizootiologic studies of plague in North American rat populations.

Paper-strip blood-sampling technique for the detection of antibody to the plague organism Yersinia pestis.

The paper-strip blood-sampling technique was evaluated for efficacy in plague passive hemagglutination tests. It is valuable for widespread serological surveys.