Surveillance for rotavirus in Argentina.

Group A rotaviruses are the major cause of severe gastroenteritis in young children worldwide. Because rotavirus vaccination appeared imminent, a nationwide surveillance program was organized between October 1996 and October 1998 in the largest Argentine cities. Surveillance for disease burden, rotavirus detection, and rotavirus typing was undertaken at nine locations. Results showed rotavirus to be associated with 42% of diarrhea admissions. Although the prevalent G types changed from year to year, common G types were found in 96% of the cases and were usually associated with common P types. Uncommon G types, G9 and G5, were found at low prevalence and uncommon G/P combinations occurred at almost every study site. These data suggest that a rotavirus vaccine could substantially decrease the rotavirus disease burden in Argentina, but that introduction of a vaccine should be accompanied by a concurrent surveillance system.

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

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.

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

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.

[Sewage sludges: application of a technique for recovering Enterovirus]. / Barros cloacales: aplicación de una técnica para recuperar Enterovirus.

The aim of this work was to develop a technique to recover viruses from sewage sludges and to set a microbiological reliable index to control the efficiency of waste-water disinfection methods. Twelve samples were collected at San Felipe treatment plant, where the waste-water from Tucumán, Argentina, is received. To free virus from solids, sludges were shaken during 20 h at 4 degrees C and supernatants were obtained by centrifugation. Penicillin, streptomycin, neomycin and amphotericin B were added to avoid the development of contaminating flora. Samples were inoculated in Vero and HeLa cells and Enterovirus (Echo 7, Echo 11 and Echo 21) were isolated from five samples.

Barros cloacales: aplicación de una técnica para recuperar Enterovirus / A recovery technique for enteroviruses in sewage sludges

El objetivo de este trabajo es aplicar una técnica para recuperar virus en barros cloacales y disponer de una metodología microbiológica confiable, que permita controlar la eficacia de métodos de desinfección de aguas residuales. Se recogieron 12 muestras de barros cloacales en la Planta de Tratamiento de San Felipe, que recibe las aguas residuales de la ciudad de San Miguel de Tucumán, Argentina. Para liberar los virus asociados a sólidos, los barros se agitaron durante 20 h a 4§C, con agitador magnético a 150-200 rpm y se centrifugaron a 2500 g 10 min. Los sobrenadantes obtenidos se descontaminaron con mezcla de penicilina, estreptomicina, neomicina y anfotericina B. Las muestras se inocularon sin concentrar en células HeLa y Vero, resultando 5 aislamientos positivos y tipificándose 3 Enterovirus: Echo 7, Echo 11 y Echo 21. Los resultados indican la necesidad de un seguimiento de contaminación viral, en caso de aplicar los barros en agricultura

Barros cloacales: aplicación de una técnica para recuperar Enterovirus / A recovery technique for enteroviruses in sewage sludges

El objetivo de este trabajo es aplicar una técnica para recuperar virus en barros cloacales y disponer de una metodología microbiológica confiable, que permita controlar la eficacia de métodos de desinfección de aguas residuales. Se recogieron 12 muestras de barros cloacales en la Planta de Tratamiento de San Felipe, que recibe las aguas residuales de la ciudad de San Miguel de Tucumán, Argentina. Para liberar los virus asociados a sólidos, los barros se agitaron durante 20 h a 4ºC, con agitador magnético a 150-200 rpm y se centrifugaron a 2500 g 10 min. Los sobrenadantes obtenidos se descontaminaron con mezcla de penicilina, estreptomicina, neomicina y anfotericina B. Las muestras se inocularon sin concentrar en células HeLa y Ve

Anticipating rotavirus vaccines: review of epidemiologic studies of rotavirus diarrhea in Argentina.

Rotavirus is the most common cause of severe diarrhea in children worldwide, and vaccines currently being field-tested could be available for childhood immunization in several years. To assess the rotavirus disease burden in Argentina and the value of future national surveillance for the disease, we reviewed available data on rotavirus detections reported by published and unpublished studies conducted in nine Argentine cities and by a multicenter study. Data from these studies indicated that rotavirus was detected in 20% of 5,226 specimens (within a range of 6% to 54% for different studies) from children hospitalized for diarrhea and in 9% of 6,587 specimens (within a range of 5% to 22% for different studies) from children who were outpatients, members of mixed populations (hospitalized patients and outpatients), or survey subjects in community-based studies. The hospital data showed that while rotavirus was detected throughout the year, a peak occurred during the winter months (May-July) when up to half of the children with diarrhea were found positive for rotavirus. Attempted serotyping of 294 rotavirus-positive specimens for G-protein by three laboratories was successful in 230 cases (78%); the resulting data indicated that serotype G1 was the most common (being present in 60% of the successfully serotyped specimens), followed by G2 (in 20%), G4 (in 14%), and G3 (in 5%). Based on national data for Argentina, we estimate that in 1991 there were roughly 84,500 rotavirus-associated outpatient visits (1 for every 8 births) and 21,000 hospitalizations averaging 4 days in length (1 for every 31 births), all of which entailed direct medical costs estimated at US$ 27.7 million. These preliminary data show that the rotavirus disease burden in Argentine children is extensive and could be decreased by a safe and effective vaccine. Further surveillance is needed to improve our understanding of the epidemiology and distribution of rotavirus strains in Argentina, to more accurately assess the cost-effectiveness of a rotavirus vaccine program, and to indicate what methods might best be used to monitor such a program's impact.

Detección de rotavirus no-A en Tucumán / Detection of non-A rotavirus in Tucumán

Se informa un caso de gastroenteritis infecciosa (GEI) causada por un Rotavirus (RV) no-A en la provincia de Tucumán. La muestra de materia fecal resultó negativa en la prueba de enzimoinmunoensayo (ELISA) para RV del grupo A y por electroforesis en gel de poliacrilamida del RNA viral presentó un bandeo genómico coincidente con el descripto por Pedley para los RV clasificados en el grupo C. Esta sería la primera comunicación sobre detección de RV no-A causante de GEI humana en la República Argentina

Detección de rotavirus no-A en Tucumán / Detection of non-A rotavirus in Tucumán

Se informa un caso de gastroenteritis infecciosa (GEI) causada por un Rotavirus (RV) no-A en la provincia de Tucumán. La muestra de materia fecal resultó negativa en la prueba de enzimoinmunoensayo (ELISA) para RV del grupo A y por electroforesis en gel de poliacrilamida del RNA viral presentó un bandeo genómico coincidente con el descripto por Pedley para los RV clasificados en el grupo C. Esta sería la primera comunicación sobre detección de RV no-A causante de GEI humana en la República Argentina (AU)

[Detection of non-A rotavirus in Tucumán]. / Detección de rotavirus no-A en Tucumán.

A case of infectious gastroenteritis (GEI) caused by a non-A Rotavirus (RV) in the province of Tucumán is reported. Fecal sample analysis for group A RV by enzyme immunoassay (ELISA) gave a negative result. Polyacrylamide gel electrophoresis (PAGE) of the viral RNA showed a genomic pattern coincident with that described by Pedley for RV belonging to group C. To our knowledge, this is the first communication on the detection of non-A RV as an etiological agent of human GEI in Argentina.

Detección de rotavirus no-A en Tucumán. / [Detection of non-A rotavirus in Tucumán]

A case of infectious gastroenteritis (GEI) caused by a non-A Rotavirus (RV) in the province of Tucumán is reported. Fecal sample analysis for group A RV by enzyme immunoassay (ELISA) gave a negative result. Polyacrylamide gel electrophoresis (PAGE) of the viral RNA showed a genomic pattern coincident with that described by Pedley for RV belonging to group C. To our knowledge, this is the first communication on the detection of non-A RV as an etiological agent of human GEI in Argentina.

[Electrophoretic types of rotavirus RNA during a 4-yr study of gastroenteritis in Tucumán]. / Electroferotipos del ARN de rotavirus durante cuatro años de estudio de gastroenteritis en Tucumán.

Between May 1986 and November 1989 a total of 796 faecal samples obtained from children with symptoms of acute diarrhea were analyzed. Rotavirus (RV) was detected in 166 cases by polyacrylamide gel electrophoresis of the viral RNA (PAGE) (Fig. 1). This technique allowed us to identify 19 different electropherotypes (EPT) eleven with a long pattern and 8 with a short one (Fig. 2). Two EPT's were dominant during this study; one detected in 1986 only and the other one in 1987, 1988 and 1989. During the last months of 1989 a new EPT was detected. The 8 EPT's with short patterns were the causative organisms of an outbreak during the cold season of 1987 (Table 2). These results show that the rotaviral infection is endemic in the province of Tucumán, as well as its prevalence during the winter season (Table 1).

Electroferotipos del ARN de rotavirus durante cuatro años de estudio de gastroenteritis en Tucumán. / [Electrophoretic types of rotavirus RNA during a 4-yr study of gastroenteritis in Tucumán]

Between May 1986 and November 1989 a total of 796 faecal samples obtained from children with symptoms of acute diarrhea were analyzed. Rotavirus (RV) was detected in 166 cases by polyacrylamide gel electrophoresis of the viral RNA (PAGE) (Fig. 1). This technique allowed us to identify 19 different electropherotypes (EPT) eleven with a long pattern and 8 with a short one (Fig. 2). Two EPTs were dominant during this study; one detected in 1986 only and the other one in 1987, 1988 and 1989. During the last months of 1989 a new EPT was detected. The 8 EPTs with short patterns were the causative organisms of an outbreak during the cold season of 1987 (Table 2). These results show that the rotaviral infection is endemic in the province of Tucumán, as well as its prevalence during the winter season (Table 1).

[Enzyme immunoassay for rotavirus using nylon as the solid phase]. / Enzimoinmunoanálisis para rotavirus con nylon como fase sólida.

An enzyme-linked immunoassay (EIA) to detect Rotavirus in stools is described. Antibodies prepared in rabbits were immobilized on small nylon cubes as capture phase and enzyme conjugated antibodies were used to reveal the reaction. The conjugate was prepared with horseradish peroxidase by the Nakane periodate oxidation method. The solid phase consisted of 3 mm nylon cubes (66 CNL Du-cilo) previously submitted to partial acid hydrolysis to liberate amino-reactive groups. Glutaraldehyde was employed to couple the capturing antibody to the solid phase resulting in a covalent linkage between the gamma-globulin and the nylon. Phenylenediamine in citrate buffer pH 5.0 with 0.5% hydrogen peroxide was used as revealing substrate. EIA was performed as follows: stools watery extracts were incubated 1 h at 37 degrees C with antibody-treated nylon cubes, and then with enzyme conjugate, rinsed with distilled water and substrate-added. Samples developing colour, with optical density of at least 0.350 at 492 nm, were considered positive. The method showed good correlation with a commercial kit.

Enzimoinmunoanálisis para rotavirus con nylon como fase sólida. / [Enzyme immunoassay for rotavirus using nylon as the solid phase]

An enzyme-linked immunoassay (EIA) to detect Rotavirus in stools is described. Antibodies prepared in rabbits were immobilized on small nylon cubes as capture phase and enzyme conjugated antibodies were used to reveal the reaction. The conjugate was prepared with horseradish peroxidase by the Nakane periodate oxidation method. The solid phase consisted of 3 mm nylon cubes (66 CNL Du-cilo) previously submitted to partial acid hydrolysis to liberate amino-reactive groups. Glutaraldehyde was employed to couple the capturing antibody to the solid phase resulting in a covalent linkage between the gamma-globulin and the nylon. Phenylenediamine in citrate buffer pH 5.0 with 0.5

hydrogen peroxide was used as revealing substrate. EIA was performed as follows: stools watery extracts were incubated 1 h at 37 degrees C with antibody-treated nylon cubes, and then with enzyme conjugate, rinsed with distilled water and substrate-added. Samples developing colour, with optical density of at least 0.350 at 492 nm, were considered positive. The method showed good correlation with a commercial kit.