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.

Molecular medicine: the present and the future.

In the recent past, major achievements have been obtained in the understanding of the molecular defects at the basis of several different diseases. The field of 'Molecular Medicine' has thus become more solid, and several reports have been published linking the basic molecular investigation to the clinical practice. In line with this new approach to medicine a Symposium was organized where the linkage between investigations in basic science could be explored in view of clinical disorders, and vice versa. in Rosario, Argentina, September 9-11, 1999, molecular biologists, molecular pathologists and clinicians discussed the molecular defects possibly at the basis of some common diseases. This report summarizes the presentations and discussions during the symposium.

Epidemiology of gallstone disease in Argentina: prevalences in the general population and European descendants.

To assess gallstone disease prevalence in Argentina, a random sample of the Rosario City population was studied, considering already known associated factors, and analyzing ethnic groups living in the city. A total of 1,173 participants (69% response), both sexes, 20 years and older were studied. Each subject underwent an abdominal ultrasound examination, a blood test, and a standardized questionnaire. It was seen that gallstone disease prevalence (gallstones or cholecystectomy), overall was 20.5% (23.8% in women and 15.5% in men; (P = 0.0005), and was associated with age and body mass index in both sexes, and with pregnancy number and hypertriglyceridemia in women. As regards ancestors' nationalities, Italian and Spanish descendants presented higher prevalence rates for all age groups than those described in Italy and Spain. Thus far, in a subsample of 78% of nonparticipants submitted to a new home visit, presence of cholecystectomy or symptoms did not differ from participants, supporting the validity of our results.

[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(AU)

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

Hepatitis B seroprevalence in Latin America.

The seroprevalence of hepatitis B was investigated in over 12,000 subjects in six countries of Latin America: Argentina, Brazil, Chile, the Dominican Republic, Mexico, and Venezuela. Each study population was stratified according to age, gender, and socioeconomic status. Antibodies against hepatitis B core antigen (anti-HBc) were measured in order to determine hepatitis B infection. The highest overall seroprevalence was found in the Dominican Republic (21.4%), followed by Brazil (7.9%), Venezuela (3.2%), Argentina (2.1%), Mexico (1.4%), and Chile (0.6%). In all the countries an increase in seroprevalence was found among persons 16 years old and older, suggesting sexual transmission as the major route of infection. In addition, comparatively high seroprevalence levels were seen at an early age in the Dominican Republic and Brazil, implicating a vertical route of transmission.

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.

[Hepatitis A virus infection in children in Argentina: a pilot study]. / Infección por virus de hepatitis A (HAV) en niños en Argentina. Ensáyo piloto.

UNLABELLED: The severity and/or the prognostic of infections with the hepatitis A virus (HAV) is related to the age at which the infection occurs. Since transmission of the virus occurs by the fecal-oral route, the prevalence and age-relate incidence of infection is determined by the adequacy of sanitation hygienic measures and the socio economic level of exposed populations. Thus, the disease is having an increasing impact in developing countries with improving sanitary standards whereas inhabitants of industrialized countries are particularly at risk while visiting under-developed countries. We have established a cooperative group for the serologic study of children range between six months to ten years old, without sintomatology of acute hepatitis. The patients live in Buenos Aires, San Justo, Trelew, Rosario and Tucumán cities. We studied 3699 children. The specific Ab-antiHAV IgG were measured by enzyme immunoassay with commercial available kits (Organon and-or Abbott). The variable of study were age, sex and water quality. RESULTS: 45.19% were of San Justo, 26.15% of Rosario, 13% of Buenos Aires, 8.37% of Trelew and 7.29% of Tucumán. We observed the highest of possibility percentage (%POS) in Tucumán (81.4%), followed by San Justo (57.8%), Rosario (46.5%), Trelew (41.99%) and Buenos Aires (29.4%). In all the cities the lowest %POS was found in children under three years old. Between three and six years old the results were variable and an increase in %POS was observed related to the growth. The global %POS was 51.56%. CONCLUSIONS: This study confirms Argentina as a high endemic country for HAV infection. A global vaccination program is the only strategy that has the potential to prevent recurrent epidemics of hepatitis A and its erradication.

Infeccion por virus de hepatitis A (HAV) en ninos en Argentina: ensayo piloto / Hepatitis A virus infection in children in Argentina: a pilot study

Objetivos: Determinar la curva de infección del HAV en niños menores de diez años. Establecer estrategias de vacunación en la Argentina. Material y Métodos: se etableció un grupo cooperativo para el rastreo serológico de niños entre los seis meses y los diez años de edad, sin sintomatología y/o cuadro clínico de hepatitis aguda, tomando como grupo inicial de trabajo a Centros de las ciudades de Bs. As., San Justo (Pcia, de Bs. As.), Trelew (Chubut), Rosario (Santa Fe) y Tucumán. Se estudiaran 3699 niños para Anti-HAV-IgG por ELISA (Oragnon y Abbott). Las variables de inclusión fueron: edad, sexo y calidad de agua. Resultados: 45.19 por ciento de las muestras fueron de San Justo, 26.15 por ciento de Rosario, 13 por ciento de Buenos Aires, 7.29 por ciento de Tucumán y 8.37 por ciento de Trelew. 1) Se observó el mayor porcentaje de positividad (porcentajePOS) en Tucuman (81.4 por ciento) seguido por San Justo (57.8 por ciento) y Rosario (44.3 por ciento). 2) En todas las ciudades los menores porcentajePOS correspondieron a menores de tres años. 3) La mayor dispersión del porcentajePOS ocurre entre los tres y seis años de edad. 4) en todo el muestreo se observó un valor creciente de porcentajePOS con pendientes similares, excepto para Trelew, donde aparece un pico a los cuatro años atribuíble a las características de la muestra. 5) El porcentajePOS global para la muestra fue de 51.56 por ciento. Conclusiones: 1) Este trabajo demuestra que nuestro país es de alta endemicidad para la infección por HAV. 2) La vacunación a corta edad sería la estrategia más adecuada para el control de la hepatitis A y la erradicación de la infección por el HAV. (AU)

Infeccion por virus de hepatitis A (HAV) en ninos en Argentina: ensayo piloto / Hepatitis A virus infection in children in Argentina: a pilot study

Objetivos: Determinar la curva de infección del HAV en niños menores de diez años. Establecer estrategias de vacunación en la Argentina. Material y Métodos: se etableció un grupo cooperativo para el rastreo serológico de niños entre los seis meses y los diez años de edad, sin sintomatología y/o cuadro clínico de hepatitis aguda, tomando como grupo inicial de trabajo a Centros de las ciudades de Bs. As., San Justo (Pcia, de Bs. As.), Trelew (Chubut), Rosario (Santa Fe) y Tucumán. Se estudiaran 3699 niños para Anti-HAV-IgG por ELISA (Oragnon y Abbott). Las variables de inclusión fueron: edad, sexo y calidad de agua. Resultados: 45.19 por ciento de las muestras fueron de San Justo, 26.15 por ciento de Rosario, 13 por ciento de Buenos Aires, 7.29 por ciento de Tucumán y 8.37 por ciento de Trelew. 1) Se observó el mayor porcentaje de positividad (porcentajePOS) en Tucuman (81.4 por ciento) seguido por San Justo (57.8 por ciento) y Rosario (44.3 por ciento). 2) En todas las ciudades los menores porcentajePOS correspondieron a menores de tres años. 3) La mayor dispersión del porcentajePOS ocurre entre los tres y seis años de edad. 4) en todo el muestreo se observó un valor creciente de porcentajePOS con pendientes similares, excepto para Trelew, donde aparece un pico a los cuatro años atribuíble a las características de la muestra. 5) El porcentajePOS global para la muestra fue de 51.56 por ciento. Conclusiones: 1) Este trabajo demuestra que nuestro país es de alta endemicidad para la infección por HAV. 2) La vacunación a corta edad sería la estrategia más adecuada para el control de la hepatitis A y la erradicación de la infección por el HAV.

Hepatitis B in Latin America: epidemiological patterns and eradication strategy. The Latin American Regional Study Group.

A comprehensive epidemiological analysis of hepatitis B virus (HBV) endemicity and transmission in Latin America was carried out to suggest policies and strategies for the use of hepatitis B vaccine in the region. The pattern of HBV endemicity based on available data from blood bank screening programmes and clinical and epidemiological studies varied widely: it was low in temperate South America, Mexico and some Caribbean islands; moderate in Brazil, Andean countries, part of central America and the Caribbean; and high in Hispaniola, St. Kitts/Nevis and in the Amazon basin (parts of Brazil, Peru, Venezuela, Colombia). Statistical estimates of HBV-related morbidity showed that greater than 150,000 acute HBV cases occur per year. As the endemicity of HBV varies considerably, different prevention strategies should be applied in this area. The highest priority should be the prevention of perinatal and early childhood transmission, but vaccination of adults belonging to high-risk groups should also be recommended.

Recombinant interferon alfa-2b following prednisone withdrawal in the treatment of chronic type B hepatitis.

The aim of the study was to evaluate the safety and effectiveness of interferon alfa-2b, alone and following prednisone withdrawal, in patients with chronic type B hepatitis. Thirty-five patients (27 men and eight women) were randomly allocated to two treatment groups. Group I (n = 17) received 6 weeks of prednisone followed by interferon alfa-2b (INTRON A, Schering-Plough Corporation) 10 million units subcutaneously, three times a week for 16 weeks. Group II (n = 18) was used as an untreated control group for 24 weeks, after which they received 16 weeks of treatment with the same dose of interferon as Group I. Both groups were followed up for 24 weeks after treatment. In Group I, 10/17 patients (58.8%) eliminated hepatitis B e antigen; 8/17 (47.1%) developed antibodies to hepatitis B e antigen; 9/17 (52.9%) became hepatitis B virus DNA negative and 1/17 (5.9%) was hepatitis B surface antigen negative at the end of follow up. In Group II, during the control phase, 1/18 (5.5%) became hepatitis B e antigen negative. When treated with interferon, 7/15 (46.7%) eliminated the e antigen, and 6/15 (40%) developed antibodies to hepatitis B e antigen and were hepatitis B virus DNA negative at the end of follow up. Serum alanine aminotransferase reached normal levels in all seroconverted patients. Liver biopsies showed a marked reduction of inflammation and disappearance of hepatitis B core antigen in liver cell nuclei in almost all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

HBeAg/anti-HBe seroconversion during and after protracted immunosuppressive treatment in type B chronic hepatitis.

Seventy-seven consecutive HBeAg-positive chronic hepatitis patients were studied from 1971 to 1983 to establish the seroconversion rate in the e system. Patients with less than a year of follow-up were not included in the study. Fifty-six patients with chronic active hepatitis (CAH) received immunosuppressive treatment (corticosteroids combined with azathioprine). The remaining twenty-one patients received no treatment, nine of them with chronic persistent hepatitis (CPH) and 12 with CAH. A retrospective study was performed with stored sera samples: HBeAg and anti-HBe were determined by RIA, and results were correlated with alanine aminotransferase (ALAT) levels in the same samples. The linearized seroconversion rate from HBeAg to anti-HBe was expressed as percent per patient-year. It was 9.6% in CPH patients and 8.8% in CAH patients without treatment. In CAH patients under immunosuppressive drugs it was as low as 1.1% and increased to 28.7% when treatment was withdrawn. ALAT levels were significantly lower in total seroconverted patients when compared with nonseroconverted (NS) patients, but no difference was found between partial seroconverted (PS) and NS patients. The results suggest that although immunosuppressive drug withdrawal may enhance seroconversion rate in type B CAH, delayed seroconversion and reported side effects during treatment stand against protracted usage of these drugs.