Características morfológicas de placas producidas por el virus rubeola en cultivos de células Vero. / [Morphologic characteristics of plaques produced by the rubella virus in cultures of Vero cells]

Under defined plaquing condition, Gilschrist strain of rubella virus showed different plaque morphology and plaque size when tested in Vero cell cultures. These differences were obtained by changing the fetal bovine serum (FBS) concentration. With 2 per cent of FBS rubella virus formed clear plaques that included a number of cells which retained the stain, while with 4 per cent of FBS it formed ring-shaped plaques. These characteristics were retained even after the Gilschrist strain was passaged several times in Vero cell cultures. The cytopathic effect in Vero cell cultures proved to be useful for the titration of rubella virus, giving infective titres in the same logarithmic order than the plaque assay.

Utilización de un método rápido para determinar infección primaria por virus rubéola. / [Use of a rapid method for determining primary infection by rubella virus]

The assay of specific immunoglobulin M (IgM) antibodies could aid in the diagnosis of early viral infection. Here we described the results obtained for IgG and IgM separation on a small column of Sephadex A-50 ion exchanger and the subsequent measure of hemagglutination inhibition antibodies for rubella virus. This diagnostic procedure combines the efficiency, rapidity and simplicity of a chromatography method with the detection of specific antibodies by reference method. The average immunoglobulin recuperation was 91

for the immunoglobulin G (IgG) and 70

for the IgM. Eighteen sera obtained from patients with presumptive diagnostic compatible with primary rubella infection, 10 from patients with known immune status for rubella virus, and 3 sera with specific IgM for BK virus, were comparatively studied by gel filtration. Sephadex G-200, enzyme immunoassay for rubella IgM antibody and Sephadex A-50 ion exchanger. The results indicated that the proposed method can be satisfactorily used for the diagnostic of primary rubella virus infection.

Estudio retrospectivo de la circulación de electroferotipos de rotavirus humanos en la ciudad de Córdoba, Argentina, 1979-1989 / Epidemiological survey of human rotavirus electropherotypes in young children in Cordoba city, Argentina, from 1979 to 1989

Con el objeto de determinar el perfil local de infección por rotavirus humanos (RVH), se llevó a cabo en la ciudad de Córdoba, Argentina, entre enero de 1979-dic. 1989, un estudio retrospectivo de la circulación de RVH. Se analizaron un total de 1839 muestras de materias fecales, obtenidas de niños menores de 4 años de edad, con diagnóstico clínico de gastroenteritis aguda. El análisis de la frecuencia y circulación de rotavirus se realizó a través de la detección y seguimiento de los diferentes electroferotipos virales utilizando presencia de rotavirus grupo A (frecuencia global: 13,9 por ciento). El análisis del ácido nucléico viral permitió identificar 16 variedades de electroferotipos: 11 de tipo largo (82,2 por ciento) y 5 del tipo corto (18,8 por ciento). Entre las variedades detectadas, las predominantes fueron: L79-5 (31,4 por ciento), L84-8 (22,1 por ciento), S79-7 (11,9 por ciento) y S86-10 (4,4 por ciento), persistiendo en la comunidad entre 4 y 6 años. Anualmente se observó la circulación de más de una variante electroferotípica. Los resultados obtenidos proveen información sobre los diferentes electroferotipos de RVH que han circulado en la ciudad de Córdoba, la aparición secuencial de estos electroferotipos y la persistencia de ellos dentro de la comunidad. La sistematización en la clasificación de los electroferotipos permite, de ahora en más, determinar la continuidad de la circulación de variantes electroferotípicas, las recombinaciones de segmentos del genoma viral entre cepas circulantes y la identificación de fuentes primarias de infección (AU)

Estudio retrospectivo de la circulación de electroferotipos de rotavirus humanos en la ciudad de Córdoba, Argentina, 1979-1989. / [Retrospective study of circulation of human rotavirus electropherotypes in the city of Córdoba, Argentina, 1979-1989]

A retrospective survey was carried out to determine the occurrence and circulation of different human rotavirus electropherotypes. Stool specimens were collected from children under four years old admitted to pediatric health services of Cordoba city, Argentina, from January 1979 to December 1989. Polyacrylamide gel electrophoresis followed by silver staining was employed for rotavirus detection. Of 1839 faecal samples 228 (13.9

) were positive for rotavirus. Examination of the electrophoretic patterns allowed us to identify 16 different electropherotypes (EPT), eleven with a long pattern (82.2

) and 5 with a short one (18.8

). The L 79-5 (31.4

), L 84-8 (22.1

), S 79-7 (11.9

) and S 86-10 (4.4

) were the predominant EPT, persisting between 4 and 6 years in the community. A cocirculation of more than one electropherotype was observed annually. The results provide information concerning the number of different electropherotypes of human rotavirus in the community, the sequential pattern of electropherotype appearance and the length of time for which an electropherotype may persist.

Resurgimiento de sarampión en ia provincia de Córdoba, Argentina, en 2000 / [Resurgence of measles in the province of Cordoba, Argentina, in 2000]

Since 1993, ministers of health of countries of America established as a goal the eradication of measles by the year 2000. As a consequence of measles eradication vaccination strategy there has been a reduction in the incidence of reported cases. Despite that, measles has continued occurring in epidemic outbreaks in many Argentinian provinces. This paper describes and analyzes the outbreak which occurred at Córdoba province, in 2000. Out of 46 serum samples analyzed from suspected cases, 6 (13.3

) were confirmed as measles by indirect immunofluorescence and enzyme immunoassays. All of them were detected in Cordoba city among both without vaccination data and unvaccinated individuals. The epidemiological links among the measles cases could be established although the geographic source of measles importation as well as the primary infection source remain unknown. The highest measles incidence was observed in the group > or = 20 year old (50

), followed by the pre-school age group (< or = 4 year old, 33.3

). The active vaccination data directed against the suspected case contacts along with a high measles population immunity probably contributed to restrict the 2000 outbreak.

Brote de sarampión en la provincia de Córdoba, Argentina, en 1998 / Measles outbreak in the province of Córdoba, Argentina, in 1998

The World Health Organization had the global target of reducing reported measles incidence from pre-vaccination era in American countries by 1995, to later eliminate indigenous measles transmission. The countries that have given priority to measles control have substantially reduced morbidity and mortality. Despite that, measles has continued occurring in epidemic outbreaks. This paper describes and analyses the outbreak occurred in Cordoba province, Argentina, in 1998. Out of 195 serum samples analysed from suspected cases, 28 (14.4) were confirmed as measles by laboratory diagnosis. Of them, 25.0 occurred among vaccinated persons, 39.3 among unvaccinated ones, and 35.7 in individuals without reported vaccine status. The highest measles incidence was in the group aged 20-29 years old (60.7), followed by the pre-school age group (1-4 years old) (21.4), the infants under one year of age (14.3) and finally 3.5 in the group older than 30 years old. These findings suggest a change in measles epidemiology with respect to the pre-vaccine era. The ability to prevent the next epidemic outbreaks will depend on the efficacy to prevent the accumulation of susceptible individuals and the maintenance of high measles vaccine coverage levels.(AU)

Brote de sarampión en la provincia de Córdoba, Argentina, en 1998. / [Measles outbreak in the province of Córdoba, Argentina, in 1998]

The World Health Organization had the global target of reducing reported measles incidence from pre-vaccination era in American countries by 1995, to later eliminate indigenous measles transmission. The countries that have given priority to measles control have substantially reduced morbidity and mortality. Despite that, measles has continued occurring in epidemic outbreaks. This paper describes and analyses the outbreak occurred in Cordoba province, Argentina, in 1998. Out of 195 serum samples analysed from suspected cases, 28 (14.4

) were confirmed as measles by laboratory diagnosis. Of them, 25.0

occurred among vaccinated persons, 39.3

among unvaccinated ones, and 35.7

in individuals without reported vaccine status. The highest measles incidence was in the group aged 20-29 years old (60.7

), followed by the pre-school age group (1-4 years old) (21.4

), the infants under one year of age (14.3

) and finally 3.5

in the group older than 30 years old. These findings suggest a change in measles epidemiology with respect to the pre-vaccine era. The ability to prevent the next epidemic outbreaks will depend on the efficacy to prevent the accumulation of susceptible individuals and the maintenance of high measles vaccine coverage levels.

Resurgimiento de sarampión en ia provincia de Córdoba, Argentina, en 2000. / [Resurgence of measles in the province of Cordoba, Argentina, in 2000]

Since 1993, ministers of health of countries of America established as a goal the eradication of measles by the year 2000. As a consequence of measles eradication vaccination strategy there has been a reduction in the incidence of reported cases. Despite that, measles has continued occurring in epidemic outbreaks in many Argentinian provinces. This paper describes and analyzes the outbreak which occurred at Córdoba province, in 2000. Out of 46 serum samples analyzed from suspected cases, 6 (13.3

) were confirmed as measles by indirect immunofluorescence and enzyme immunoassays. All of them were detected in Cordoba city among both without vaccination data and unvaccinated individuals. The epidemiological links among the measles cases could be established although the geographic source of measles importation as well as the primary infection source remain unknown. The highest measles incidence was observed in the group > or = 20 year old (50

), followed by the pre-school age group (< or = 4 year old, 33.3

). The active vaccination data directed against the suspected case contacts along with a high measles population immunity probably contributed to restrict the 2000 outbreak.

Agentes virales asociados al sindrome diarreico en pacientes trasplantados renales. / [Viral agents related to diarrheic syndrome in kidney transplanted patients]

The aim of this study was to report on the occurrence of conventional and emerging viral agents as well as their etiological link with diarrhea in kidney transplanted subjects from Cordoba, Argentina. A total of 42 stool samples were analysed. They were obtained from both ambulatory and hospitalized kidney transplanted patients with and without diarrhea after transplant. All patients were under immunosuppressive treatment with steroids, azatioprine and cyclosporine or tacrolimus. Results revealed the presence of group A rotavirus and picobimavirus in three patients suffering from severe diarrhea (33.33

). No enteric bacterial agent was isolated from these patients. The presence of viral agents was related to high levels of cyclosporine in blood (> 290 ng/ml) or prolonged immunosuppressive treatment. On the other hand, no virus was detected in any of the samples collected from asymptomatic individuals (p < 0.05). These findings suggest that viruses are implicated in the etiology of diarrheal disease in these patients.

Red de laboratorios de Rotavirus: resultados del primer año de vigilancia / Rotavirus laboratory network: results after one year experience

Rotavirus es el principal agente productor de diarrea infantil y se ha estimado que provoca en Argentina 21.000 hospitalizaciones, 85.000 atenciones ambulatorias, y un costo mayor a los 27 millones de dolares anuales. Ante la inminente aprobación de una vacuna contra este patógeno se organizó un Sistema de Vigilancia Epidemiológica en base a una Red de laboratorios. Se presentan los resultados obtenidos luego del primer año de funcionamiento de esta Red. Se encontró que el 9 por ciento de la internación pediátrica es debido a diarrea aguda, y rotavirus se halló en el 42,1 por ciento de los casos estudiados. Se estimó que rotavirus provoca el 3,8 por ciento de las internaciones pediátricas. La internación por diarrea y la internación asociada a diarrea por rotavirus fue mayor en el primer año de vida (62 por ciento y 71,3 por ciento respectivamente). En el semestre de diciembre a mayo el número de internaciones por diarrea fue significativamente mayor que en el semestre restante. Se detectó un pico de diarreas por rotavirus entre abril y junio en las distintas Unidades centinelas. Estos resultados señalan a los rotavirus como el principal agente etiológico de la gastroenteritis infantil aguda en nuestro país y avalan la necesidad de incorporar su diagnóstico en todos los hospitales pediátricos. Los costos adicionales serán ampliamente superados por los beneficios relacionados con elmejor manejo de las camas hospitalarias, los recursos del laboratorio, y el paciente internado por diarrea, el uso correcto de antibióticos, y el control de la diseminación intrahospitalaria de rotavirus(AU)

Red de laboratorios de Rotavirus: resultados del primer año de vigilancia. / [Rotavirus laboratory network: results after one year of observation]

Rotavirus is the most common cause of severe diarrhea in children and it has been estimated that in Argentina Rotavirus is responsible for 21,000 hospitalizations, 85,000 medical attentions and an annual medical cost of US$ 27 millions. Given that a Rotavirus vaccine is about to be approved, a laboratory network based surveillance system was organized. Herein, we present the results after one year of study. Severe diarrhea was responsible for 9

of pediatric hospitalizations and rotavirus was detected in 42.1

of the diarrhea cases. We estimated that Rotavirus causes 3.8

of pediatric hospitalizations. The number of diarrhea and Rotavirus diarrhea hospitalizations was greater during the first year of life (62

and 71.3

, respectively). The number of diarrhea hospitalizations during the December-May semester was significantly higher than the rest of the year. A Rotavirus diarrhea peak was detected between April and June. These results indicate that Rotavirus is the most important etiological agent of severe diarrhea in Argentine children and show the importance of performing Rotavirus diagnosis in every pediatric hospital. The additional costs will be compensated by many benefits such as better use of antibiotics, improved nosocomial spread control, better handling of hospital beds and of laboratory resources and of the hospitalized patient.