RESUMEN
Thirty-three persons infected with West Nile fever were detected in 2002 in the Astrakhan Region; the diagnosis was confirmed serologically and the maximal number of the infected was registered in August, same year. The indices of the specific humoral immunity varied from 3.3% to 27.1%. A monitoring determined the highest infection risk among the residents of the Volga middle delta.
Asunto(s)
Vigilancia de la Población , Fiebre del Nilo Occidental/epidemiología , Virus del Nilo Occidental/aislamiento & purificación , Anticuerpos Antivirales/sangre , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Federación de Rusia/epidemiología , Estaciones del Año , Estudios Seroepidemiológicos , Población Urbana , Fiebre del Nilo Occidental/sangre , Fiebre del Nilo Occidental/diagnósticoRESUMEN
Pronounced transformation of cells in mesenteric lymph nodes, mainly in the thymus-independent zone and sinuses, was detected in albino mice experimentally infected with West Nile fever (strain 986). Maximum antigen-presenting activity was exhibited by activated macrophages, minimum activity--by dendritic cells of lymphoid follicles.
Asunto(s)
Células Presentadoras de Antígenos/metabolismo , Ganglios Linfáticos/citología , Fiebre del Nilo Occidental/inmunología , Fiebre del Nilo Occidental/patología , Animales , Células Presentadoras de Antígenos/inmunología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Activación de Linfocitos , Macrófagos/citología , Macrófagos/metabolismo , Ratones , Virus del Nilo Occidental/metabolismoRESUMEN
Immunostructure of the Astrakhan Region population to West Nile fever (WNF) was studied in the preepidemic period (1998) and after the outbreak (1999). Among the sera obtained in 1998, 63 (26.3%) were positive in neutralization reaction, 84 (27.1%) in enzyme immunoassay IgG and 20 (7.8%) in HAIR. IgM-antibodies were found in none of 142 samples. Overall number of donors having antibodies to WNF virus by three reactions reached 97 (31.6%). In the sera obtained in 1999, virus neutralizing antibodies were detected in 72(44.4%) cases, specific IgM antibodies detected by EIA_in 5(3.1%), IgG_in 44(27.1%), antihemagglutinins_in 11 (6.9%). The number of positive findings in 4 reactions in 1999 was 81(50.0%). The results of examination of the sera collected for two years (1998 and 1999) were the following: of 402 samples examined in NR positive were 135(33.6%), of 304 five (1.6%) were IgM positive, 128(27.1%) of 472 were IgG positive, and 31(7.4%) of 417 responded in HAIR. Overall index of humoral immunity for 2 years was 37.9% (in males and females 39.8 and 32.8%, respectively. In persons aged 20-29 years_36.9%, 50-59 years_42.9%. Thus, by 2-year results, antibodies to WNF virus occurred in 51.9% rural citizens and 35.0% city population.
Asunto(s)
Anticuerpos Antivirales/sangre , Brotes de Enfermedades , Fiebre del Nilo Occidental/epidemiología , Virus del Nilo Occidental/inmunología , Adulto , Donantes de Sangre , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Técnicas para Inmunoenzimas , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , Población Rural , Federación de Rusia/epidemiología , Estudios Seroepidemiológicos , Población Urbana , Fiebre del Nilo Occidental/sangreRESUMEN
Blood serum samples were obtained from patients with West Nile fever (WNF) from the city of Volgograd and its region within the disease weeks 1-3 (July-October 1999), month 6-7 (May_June 2000) and month 12-18 (May-June 2001) after the disease onset. In the sera of 40 patients examined 6-7 months after the disease onset IgM-antibodies to WNF virus were absent (dilution 1:50), IgG ones were detected in 35 patients (87.5%). 18 months after the disease IgG-antibodies were identified in 23 of 26 convalescents (88.5%). The serum samples obtained in autumn 1999 and May-June 2000 contained antihemagglutinins to WNF virus for 6-7 months in all 18 patients. In May-June 2000 the sera were positive in 38 convalescents who had WNF in 1999.
Asunto(s)
Anticuerpos Antivirales/sangre , Convalecencia , Fiebre del Nilo Occidental/inmunología , Virus del Nilo Occidental/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Pruebas de Inhibición de Hemaglutinación , Humanos , Técnicas para Inmunoenzimas , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Persona de Mediana Edad , Federación de Rusia/epidemiología , Estudios Seroepidemiológicos , Factores de Tiempo , Población Urbana , Fiebre del Nilo Occidental/sangre , Fiebre del Nilo Occidental/epidemiologíaRESUMEN
From July to September 1999, a widespread outbreak of meningoencephalitis associated with West Nile virus (Flavivirus, Flaviviridae) occurred in southern Russia, with hundreds of cases and dozens of deaths. Two strains of West Nile virus isolated from patient serum and brain-tissue samples reacted in hemagglutination-inhibition and neutralization tests with patients' convalescent-phase sera and immune ascites fluid from other strains of West Nile virus.
Asunto(s)
Encéfalo/virología , Brotes de Enfermedades , Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/aislamiento & purificación , Adolescente , Anciano , Animales , ADN Viral/sangre , Pruebas de Inhibición de Hemaglutinación , Humanos , Ratones , Persona de Mediana Edad , Pruebas de Neutralización , Federación de Rusia/epidemiología , Viremia/virología , Virus del Nilo Occidental/clasificaciónRESUMEN
Two strains of West Nile virus LEIV 27889 Vig and Ast 986 were isolated from the brain of a dead subject and from the blood of a patient, respectively, during an outbreak of serous meningitis and meningoencephalitis in July-September, 1999, in the Volgograd region, Krasnodar territory, and Astrakhan region. These strains reacted with convalescent sera in hemagglutination inhibition test, which proves their etiological role in this outbreak.