[Conditions for the transmission of Hantavirus in Rio Negro, Argentina]. / Condiciones para la transmision del hantavirus en zona andina de Río Negro, Argentina.

Hantavirus Pulmonary Syndrome (HPS) is a disease of viral etiology that affects humans causing severe acute respiratory symptoms. In Patagonia the disease is caused by the Andes Virus (AND) and transmitted by the rodent Oligoryzomys longicaudatus. The aim of this study was to identify those human activities that increase the risk of exposure to rodents, what we call "contagious scenarios". A retrospective study was performed with data obtained from cases in Rio Negro, which included clinic-epidemiological records and ecological/environmental assessment reports. The following variables were considered: age, sex, season, percentage of urbanization, geographic location, human settlements in rodent infested areas, probable source of exposure, type of activity and level of sanitary development. In total 32 cases were studied. Exposure was verified in 18 (56.2 %) cases in rural areas and 10 cases (31.3%) in small rural towns. In relation to anthropogenic environment, 24 (75%) cases were reported in developed settlements and 8 cases (25%) were related to slightly modified areas. Major exposition in El Bolson identified 8 cases of indoor activities of the total 18 reported in the area (44.5%), while in Bariloche 8 (57.1%) cases out of 14 were reported in outdoor surroundings. In general, activities that generated greater risk were work-related, accounting for 23 (71.9%) cases while 7 were related to recreational activities (28.1%). The identification of "contagious scenarios" at local level provided information for an effective application of available resources in terms of prevention and sanitary education.

Condiciones para la transmision del hantavirus en zona andina de Río negro, Argentina

El Síndrome Pulmonar por Hantavirus (SPH) es una enfermedad de etiología viral que causa en el hombre un cuadro respiratorio grave. En Patagonia, la enfermedad es causada por el virus Andes Sur (AND), transmitido por el roedor Oligoryzomys longicaudatus. El objetivo del presente trabajo fue identificar las actividades del hombre que favorecen su exposición a roedores, denominados escenarios de contagio. Se realizó un estudio retrospectivo a partir de información recolectada en investigaciones de casos ocurridos en Río Negro, mediante Fichas Clínico-Epidemiológicas e informes de evaluación ecológico/ambiental. Se definieron como variables a ser consideradas: edad, sexo, época del año, grado de urbanización, localización geográfica, integración del hombre al hábitat de roedores, fuente probable de exposición, actividad humana y nivel de saneamiento. Se estudiaron 32 casos. La exposición rural se verificó en 18 (56.2%) de los casos y 10 (31.3%) en paraje rural (grupo de viviendas en zona rural). En relación al ambiente antropogénico 24 (75%) resultaron en ambientes modificados por el hombre y 8 (25%) en áreas poco modificadas. El sitio de exposición de mayor importancia en El Bolsón fue el interior de edificaciones en 8 de los 18 casos allí registrados (44.5%), mientras que en Bariloche fueron ambientes de exterior con 8/14 (57.1%) casos. La actividad de riesgo fue laboral en 23 (71.9%) de los casos y recreacional en 7 (28.1%). Determinar los escenarios de contagio a nivel local ha aportado información para aplicar todos los recursos disponibles en materia de prevención y educación sanitaria.(AU)

Hantavirus Pulmonary Syndrome (HPS) is a disease of viral etiology that affects humans causing severe acute respiratory symptoms. In Patagonia the disease is caused by the Andes Virus (AND) and transmitted by the rodent Oligoryzomys longicaudatus. The aim of this study was to identify those human activities that increase the risk of exposure to rodents, what we call "contagious scenarios". A retrospective study was performed with data obtained from cases in Rio Negro, which included clinic-epidemiological records and ecological/environmental assessment reports. The following variables were considered: age, sex, season, percentage of urbanization, geographic location, human settlements in rodent infested areas, probable source of exposure, type of activity and level of sanitary development. In total 32 cases were studied. Exposure was verified in 18 (56.2 %) cases in rural areas and 10 cases (31.3%) in small rural towns. In relation to anthropogenic environment, 24 (75%) cases were reported in developed settlements and 8 cases (25%) were related to slightly modified areas. Major exposition in El Bolson identified 8 cases of indoor activities of the total 18 reported in the area (44.5%), while in Bariloche 8 (57.1%) cases out of 14 were reported in outdoor surroundings. In general, activities that generated greater risk were work-related, accounting for 23 (71.9%) cases while 7 were related to recreational activities (28.1%). The identification of "contagious scenarios" at local level provided information for an effective application of available resources in terms of prevention and sanitary education.(AU)

Condiciones para la transmision del hantavirus en zona andina de Río negro, Argentina

El Síndrome Pulmonar por Hantavirus (SPH) es una enfermedad de etiología viral que causa en el hombre un cuadro respiratorio grave. En Patagonia, la enfermedad es causada por el virus Andes Sur (AND), transmitido por el roedor Oligoryzomys longicaudatus. El objetivo del presente trabajo fue identificar las actividades del hombre que favorecen su exposición a roedores, denominados escenarios de contagio. Se realizó un estudio retrospectivo a partir de información recolectada en investigaciones de casos ocurridos en Río Negro, mediante Fichas Clínico-Epidemiológicas e informes de evaluación ecológico/ambiental. Se definieron como variables a ser consideradas: edad, sexo, época del año, grado de urbanización, localización geográfica, integración del hombre al hábitat de roedores, fuente probable de exposición, actividad humana y nivel de saneamiento. Se estudiaron 32 casos. La exposición rural se verificó en 18 (56.2%) de los casos y 10 (31.3%) en paraje rural (grupo de viviendas en zona rural). En relación al ambiente antropogénico 24 (75%) resultaron en ambientes modificados por el hombre y 8 (25%) en áreas poco modificadas. El sitio de exposición de mayor importancia en El Bolsón fue el interior de edificaciones en 8 de los 18 casos allí registrados (44.5%), mientras que en Bariloche fueron ambientes de exterior con 8/14 (57.1%) casos. La actividad de riesgo fue laboral en 23 (71.9%) de los casos y recreacional en 7 (28.1%). Determinar los escenarios de contagio a nivel local ha aportado información para aplicar todos los recursos disponibles en materia de prevención y educación sanitaria.

Hantavirus Pulmonary Syndrome (HPS) is a disease of viral etiology that affects humans causing severe acute respiratory symptoms. In Patagonia the disease is caused by the Andes Virus (AND) and transmitted by the rodent Oligoryzomys longicaudatus. The aim of this study was to identify those human activities that increase the risk of exposure to rodents, what we call "contagious scenarios". A retrospective study was performed with data obtained from cases in Rio Negro, which included clinic-epidemiological records and ecological/environmental assessment reports. The following variables were considered: age, sex, season, percentage of urbanization, geographic location, human settlements in rodent infested areas, probable source of exposure, type of activity and level of sanitary development. In total 32 cases were studied. Exposure was verified in 18 (56.2 %) cases in rural areas and 10 cases (31.3%) in small rural towns. In relation to anthropogenic environment, 24 (75%) cases were reported in developed settlements and 8 cases (25%) were related to slightly modified areas. Major exposition in El Bolson identified 8 cases of indoor activities of the total 18 reported in the area (44.5%), while in Bariloche 8 (57.1%) cases out of 14 were reported in outdoor surroundings. In general, activities that generated greater risk were work-related, accounting for 23 (71.9%) cases while 7 were related to recreational activities (28.1%). The identification of "contagious scenarios" at local level provided information for an effective application of available resources in terms of prevention and sanitary education.

Condiciones para la transmision del hantavirus en zona andina de Río Negro, Argentina. / [Conditions for the transmission of Hantavirus in Rio Negro, Argentina].

Hantavirus Pulmonary Syndrome (HPS) is a disease of viral etiology that affects humans causing severe acute respiratory symptoms. In Patagonia the disease is caused by the Andes Virus (AND) and transmitted by the rodent Oligoryzomys longicaudatus. The aim of this study was to identify those human activities that increase the risk of exposure to rodents, what we call "contagious scenarios". A retrospective study was performed with data obtained from cases in Rio Negro, which included clinic-epidemiological records and ecological/environmental assessment reports. The following variables were considered: age, sex, season, percentage of urbanization, geographic location, human settlements in rodent infested areas, probable source of exposure, type of activity and level of sanitary development. In total 32 cases were studied. Exposure was verified in 18 (56.2

) cases in rural areas and 10 cases (31.3

) in small rural towns. In relation to anthropogenic environment, 24 (75

) cases were reported in developed settlements and 8 cases (25

) were related to slightly modified areas. Major exposition in El Bolson identified 8 cases of indoor activities of the total 18 reported in the area (44.5

), while in Bariloche 8 (57.1

) cases out of 14 were reported in outdoor surroundings. In general, activities that generated greater risk were work-related, accounting for 23 (71.9

) cases while 7 were related to recreational activities (28.1

). The identification of "contagious scenarios" at local level provided information for an effective application of available resources in terms of prevention and sanitary education.

Expansión geográfica del síndrome pulmonar por hantavirus en la Argentina: Informe del caso más austral / Geographic expansion of hantavirus pulmonary syndrome in Argentina: The southernest case report

Desde 1995 se han informado más de 1000 casos de síndrome pulmonar por hantavirus (SPH) en la Argentina, enfermedad grave y muchas veces fatal para los humanos. La mayoría de los casos fueron asociados al virus Andes (AND) único hantavirus que ha sido informado como causante de transmisión persona a persona. Se han descrito varios linajes patogénicos del virus AND, de los cuales AND Sur, cuyo reservorio es el roedor Oligoryzomys longicaudatus, afecta a la región patagónica de Argentina y Chile. En el presente estudio se informan las manifestaciones clínicas y las características epidemiológicas de un caso de SPH. El objetivo fue describir la presentación clínica del caso, su entorno epidemiológico, el sitio probable de contagio, la variante viral implicada y su relación con los casos más cercanos notificados. Se realizó el seguimiento clínico, el diagnóstico serológico y molecular y la investigación epidemiológica, incluyendo un estudio de la población de roedores reservorios en las áreas involucradas. Se trató de una presentación clásica de SPH moderada, causada por el linaje viral AND sur y su secuencia nucleotídica se comparó con casos del sur argentino y chileno. El caso de hantavirus investigado resultó ser el más austral (48° 46´ 1.2´´ S; 70° 15´ 0´´ O) notificado hasta el momento e involucró a una nueva provincia argentina.

Since 1995 more than 1000 cases of hantavirus pulmonary syndrome (HPS) were reported in Argentina, a severe disease and often fatal to humans. Most cases were associated with Andes virus (AND) that caused few events of person-to-person transmission. Several lineages of pathogenic AND viruses have been described, including AND South, hosted by the rodent Oligoryzomys longicaudatus which affects the Patagonian region of Argentina and Chile. We studied the clinical and epidemiological characteristics of a HPS case. The objective was to describe the clinical presentation of the case, its epidemiology, the likely site of infection, the viral variant implicated and its relationship with the closest reported cases. We carried out the clinical follow up, serological and molecular diagnosis and the epidemiological research, including a rodent reservoir study. The clinical presentation of the case was the classical and moderate, caused by AND South virus. Its viral nucleotide sequence was compared with cases from Southern Argentina and Chile. This case was found to be the most Southern (48° 46´ 1.2´´ S; 70° 15´ O) case reported and involved a new Argentinean province.

[Geographic expansion of hantavirus pulmonary syndrome in Argentina. The southernest case report]. / Expansión geográfica del síndrome pulmonar por Hantavirus en la Argentina. Informe del caso más austral.

Since 1995 more than 1000 cases of hantavirus pulmonary syndrome (HPS) were reported in Argentina, a severe disease and often fatal to humans. Most cases were associated with Andes virus (AND) that caused few events of person-to-person transmission. Several lineages of pathogenic AND viruses have been described, including AND South, hosted by the rodent Oligoryzomys longicaudatus which affects the Patagonian region of Argentina and Chile. We studied the clinical and epidemiological characteristics of a HPS case. The objective was to describe the clinical presentation of the case, its epidemiology, the likely site of infection, the viral variant implicated and its relationship with the closest reported cases. We carried out the clinical follow up, serological and molecular diagnosis and the epidemiological research, including a rodent reservoir study. The clinical presentation of the case was the classical and moderate, caused by AND South virus. Its viral nucleotide sequence was compared with cases from Southern Argentina and Chile. This case was found to be the most Southern (48 degrees 46' 1.2'' S; 70 degrees 15' O) case reported and involved a new Argentinean province.

Hantavirus antibodies in rodents and human cases with pulmonary syndrome, Rio Negro, Argentina.

In Río Negro Province, Argentina, human cases of hantavirus pulmonary syndrome (HPS) appeared in the region of subantarctic forests. The Andes virus (ANDV) has been identified in the region both in Oligoryzomys longicaudatus rodents and in humans, with the main transmission being from rodents to humans but also showing the possibility of human to human transmission. Between 1996 and 2004, in 40 campaigns, 29.960 night-traps for capturing live rodents were set up. Blood samples were obtained from the rodents and processed using enzyme immunoassay with recombinant antigens made from ANDV. A total of 1767 rodents were captured, with a capture success of 5.9% and an antibody prevalence of 2.1%. Important differences were observed among the species captured from Andes and Steppe regions. Seropositive Oligoryzomys longicaudatus, Abrotrix olivaceus, Abrotrix xanhtothinus and Loxodontomus microtus were captured. During the 1993-2004 period, 40 HPS cases were registered.

Hantavirus antibodies in rodents and human cases with pulmonary syndrome, Río Negro, Argentina / Anticuerpos contra hantavirus en roedores y casos humanos con síndrome pulmonar, Río Negro, Argentina

In Río Negro Province, Argentina, human cases of hantavirus pulmonary syndrome (HPS) appeared in the region of subantartic forests. The Andes virus (ANDV) has been identified in the region both in Oligoryzomys longicaudatus rodents and in humans, with the main transmission being from rodents to humans but also showing the possibility of human to human transmission. Between 1996 and 2004, in 40 campaigns, 29.960 night-traps for capturing live rodents were set up. Blood samples were obtained from the rodents and processed using enzyme immunoassay with recombinant antigens made from ANDV. A total of 1767 rodents were captured, with a capture success of 5.9% and an antibody prevalence of 2.1%. Important differences were observed among the species captured from Andes and Steppe regions. Seropositive Oligoryzomys longicaudatus, Abrotrix olivaceus, Abrotrix xanhtothinus and Loxodontomus microtus were captured. During the 1993-2004 period, 40 HPS cases were registered.

En la Provincia de Río Negro, Argentina, se presentaron casos humanos de síndrome pulmonar por hantavirus (SPH) en la región de los bosques subantárticos. El virus Andes (AND) fue identificado en la región, tanto en el roedor Oligoryzomys longicaudatus como en seres humanos, demostrándose la transmisión principalmente del roedor al hombre y la posibilidad de la transmisión de persona a persona. Para ello, se procedió a la colocación de 29.960 trampas para captura viva de roedores, tipo Sherman, en 40 operativos efectuados desde 1996 hasta 2004. Se obtuvieron muestras de sangre de los roedores, las que fueron procesadas mediante enzimoinmunoensayo con antígenos recombinantes elaborados a partir de virus AND. Fueron capturados 1767 roedores, con un éxito de trampeo del 5.9% y una prevalencia de anticuerpos contra hantavirus del 2.1%. Se observaron importantes diferencias en las especies capturadas en cada una de las regiones. Se capturaron O. longicaudatus, Abrothrix olivaceus y Abrothrix xanhtothinus y Loxodontomys microtus seropositivos. Se registraron 40 casos humanos en el período 1993-2004.

Clusters of hantavirus infection, southern Argentina.

Person-to-person transmission of a hantavirus was first confirmed during a 1996 outbreak of hantavirus pulmonary syndrome in southern Argentina, where Andes virus is endemic. To identify other episodes of secondary transmission, we reviewed reports of 51 cases of hantavirus infection from this region (November 1993-June 2005). Nine clusters involving 20 cases (39.2%) were found. Two patients, who had symptoms 3 weeks after they shared risks for rodent exposure, were considered a cluster. The other 8 clusters each began with an index case, which was almost always fatal, followed 19-40 days later by the illness of at least 1 person who had close and prolonged contact with the index case-patient. Person-to-person transmission was considered the probable source of these 8 clusters. The probability of initiating secondary cases was 41% for patients who died versus 4% for those who survived (p = 0.005). Interpersonal transmission of Andes virus infection should be considered even when rodent exposure cannot be definitively excluded.

[Epidemiological surveillance of cystic echinococcosis in dogs, sheep farms and humans in the Rio Negro Province]. / Vigilancia epidemiológica de la equinococcosis quística en perros, establecimientos ganaderos y poblaciones humanas en la provincia de Río Negro.

The surveillance of infection for Echinococcus granulosus in the Province of Rio Negro during 1980-2002 included serological and ultrasonographic screening in humans and arecoline test in dogs. In lieu of the limitations of the arecoline test the proposal was to supplant that test for the copro ELISA-copro/Western Blot complex applied to feces collected from the environment. The objective was to compare the pros and cons of the two tests and to evaluate the human and the canine infection prevalence. The working area encompassed 7 Departments with systematic canine parasiticide activities (Program Area) and 4 Departments, not endemic, as Control Area. The arecoline test was applied to the dogs in assembled groups with the voluntary participation of their owners (not randomized sampling). Samples for the detection of coproantigens were obtained from sheep farms selected at random and analyzed by the complex copro-ELISA /Western Blot. Prevalence in man was determined by screening the school population (6 to 14 years old) by ultrasound, and by means of the compulsory notification of cases from the official system. Dogs (416) were tested with arecoline, 365 of which belonged to the Program Area. Of these 19 (5.2%) resulted positive, while none of 51 dogs from the Control Area were positive. Samples (748) of feces were tested to detect coproantigens, obtaining 37 positive samples within the Program Area and 4 within the Control Area. Farms (271) from the livestock estate unit were evaluated, out of which 236 belonged to the Program Area, gave 32 (13.6%) positive results, while 4 (11.4%) of 35 from the Control Area resulted positive. Sonography tests (7421) were done in the Program Area detecting 40 (0.5%) carriers, while in the Control Area, over 1732 tests, 9 (0.5%) resulted positive. The arecoline test provides information about the dog prevalence while the detection of coproantigens in feces collected from the environment allowed to enhance the quality of the information, and the identification of environments where specific control activities focusing on risk must be concentrated. Also the study allowed to recognize new transmission areas.

Vigilancia epidemiologica de la equinococcosis quistica en perros, establecimientos ganaderos y poblaciones humanas en la Provincia de Rio Negro / Vigilancia epidemiologica de la equinococcosis quistica en perros, establecimientos ganaderos y poblaciones humanas en la Provincia de Rio Negro

La vigilancia de la equinococcosis quística para detectar infestación por Echinococcus granulosus en la Provincia de Río Negro en el período 1980-2002 fue efectuada en el hombre mediante encuestas serológicas y ultrasonográficas en población joven, y en el perro por el test de arecolina. Dadas las limitaciones de esta técnica, se planteó suplantarla por el complejo copro ELISA Western Blot en heces caninas recolectadas del suelo. El objetivo del presente trabajo fue comparar las ventajas y limitaciones de las dos técnicas para medir la prevalencia de la infección en el perro, y evaluar la prevalencia actual de la infección en el hombre y en el perro. Elárea de trabajo comprendió 7 Departamentos endémicos con Programas de desparasitación canina sistemática (Area Programa) y 4 Departamentos no endémicos como Area Testigo. El test de arecolina se aplicó en los perros, con concurrencia voluntaria de sus propietarios (muestreo no aleatorizado). Las muestras para detección de coproantígenosfueron obtenidas de establecimientos ganaderos seleccionados en forma aleatorizada. En el hombre se determinó la prevalencia mediante tamizajes ultrasonográficos en escolares de 6 a 14 años y la incidencia por medio del sistema oficial de notificación de casos sintomáticos. Se dosificaron con arecolina 416 perros resultando 19 (5.2%) positivos en el Area Programa y ninguno positivo en el Area Testigo. Para la detección de coproantígenos se obtuvieron 748 muestras de materia fecal de 271 establecimientos ganaderos, resultando 37 muestras y 32 establecimientos (13.6%) positivos en el Area Programa y 4 muestras y 4 establecimientos (11.4%, IC: 0.3-32.3) positivos en el Área Testigo. En el Area Programa se efectuaron 7421 ecografías abdominales a escolares, detectándose 40 (0.5%) casos conimágenes compatibles con hidatidosis, mientras en el área testigo se efectuaron 1732 ecografías con 9 (0.5%) casos positivos...

The surveillance of infection for Echinococcus granulosus in the Provinceof Rio Negro during 1980-2002 included serological and ultrasonographic screening in humans and arecoline testin dogs. In lieu of the limitations of the arecoline test the proposal was to supplant that test for the copro Elisacopro/Western Blot complex applied to feces collected from the environment. The objective was to compare the pros and cons of the two tests and to evaluate the human and the canine infection prevalence. The working area encompassed 7 Departments with systematic canine parasiticide activities (Program Area) and 4 Departments, not endemic, as Control Area. The arecoline test was applied to the dogs in assembled groups with the voluntary participation of their owners (not randomized sampling). Samples for the detection of coproantigens were obtained from sheep farms selected at random and analyzed by the complex copro-LISA /Western Blot. Prevalence inman was determined by screening the school population (6 to 14 years old) by ultrasound, and by means of the compulsory notification of cases from the official system. Dogs (416) were tested with arecoline, 365 of whichbelonged to the Program Area. Of these 19 (5.2%) resulted positive, while none of 51 dogs from the Control Areawere positive. Samples (748) of feces were tested to detect coproantigens, obtaining 37 positive samples withinthe Program Area and 4 within the Control Area. Farms (271) from the livestock estate unit were evaluated, outof which 236 belonged to the Program Area, gave 32 (13.6%) positive results, while 4 (11.4%) of 35 from theControl Area resulted positive. Sonography tests (7421) were done in the Program Area detecting 40 (0.5%)carriers, while in the Control Area, over 1732 tests, 9 (0.5%) resulted positive...

Vigilancia epidemiologica de la equinococcosis quistica en perros, establecimientos ganaderos y poblaciones humanas en la Provincia de Rio Negro / Vigilancia epidemiologica de la equinococcosis quistica en perros, establecimientos ganaderos y poblaciones humanas en la Provincia de Rio Negro

La vigilancia de la equinococcosis quística para detectar infestación por Echinococcus granulosus en la Provincia de Río Negro en el período 1980-2002 fue efectuada en el hombre mediante encuestas serológicas y ultrasonográficas en población joven, y en el perro por el test de arecolina. Dadas las limitaciones de esta técnica, se planteó suplantarla por el complejo copro ELISA Western Blot en heces caninas recolectadas del suelo. El objetivo del presente trabajo fue comparar las ventajas y limitaciones de las dos técnicas para medir la prevalencia de la infección en el perro, y evaluar la prevalencia actual de la infección en el hombre y en el perro. Elárea de trabajo comprendió 7 Departamentos endémicos con Programas de desparasitación canina sistemática (Area Programa) y 4 Departamentos no endémicos como Area Testigo. El test de arecolina se aplicó en los perros, con concurrencia voluntaria de sus propietarios (muestreo no aleatorizado). Las muestras para detección de coproantígenosfueron obtenidas de establecimientos ganaderos seleccionados en forma aleatorizada. En el hombre se determinó la prevalencia mediante tamizajes ultrasonográficos en escolares de 6 a 14 años y la incidencia por medio del sistema oficial de notificación de casos sintomáticos. Se dosificaron con arecolina 416 perros resultando 19 (5.2%) positivos en el Area Programa y ninguno positivo en el Area Testigo. Para la detección de coproantígenos se obtuvieron 748 muestras de materia fecal de 271 establecimientos ganaderos, resultando 37 muestras y 32 establecimientos (13.6%) positivos en el Area Programa y 4 muestras y 4 establecimientos (11.4%, IC: 0.3-32.3) positivos en el Area Testigo. En el Area Programa se efectuaron 7421 ecografías abdominales a escolares, detectándose 40 (0.5%) casos conimágenes compatibles con hidatidosis, mientras en el área testigo se efectuaron 1732 ecografías con 9 (0.5%) casos positivos...(AU)

The surveillance of infection for Echinococcus granulosus in the Provinceof Rio Negro during 1980-2002 included serological and ultrasonographic screening in humans and arecoline testin dogs. In lieu of the limitations of the arecoline test the proposal was to supplant that test for the copro Elisacopro/Western Blot complex applied to feces collected from the environment. The objective was to compare the pros and cons of the two tests and to evaluate the human and the canine infection prevalence. The working area encompassed 7 Departments with systematic canine parasiticide activities (Program Area) and 4 Departments, not endemic, as Control Area. The arecoline test was applied to the dogs in assembled groups with the voluntary participation of their owners (not randomized sampling). Samples for the detection of coproantigens were obtained from sheep farms selected at random and analyzed by the complex copro-LISA /Western Blot. Prevalence inman was determined by screening the school population (6 to 14 years old) by ultrasound, and by means of the compulsory notification of cases from the official system. Dogs (416) were tested with arecoline, 365 of whichbelonged to the Program Area. Of these 19 (5.2%) resulted positive, while none of 51 dogs from the Control Areawere positive. Samples (748) of feces were tested to detect coproantigens, obtaining 37 positive samples withinthe Program Area and 4 within the Control Area. Farms (271) from the livestock estate unit were evaluated, outof which 236 belonged to the Program Area, gave 32 (13.6%) positive results, while 4 (11.4%) of 35 from theControl Area resulted positive. Sonography tests (7421) were done in the Program Area detecting 40 (0.5%)carriers, while in the Control Area, over 1732 tests, 9 (0.5%) resulted positive...(AU)

Vigilancia epidemiologica de la equinococcosis quistica en perros, establecimientos ganaderos y poblaciones humanas en la Provincia de Rio Negro / Vigilancia epidemiologica de la equinococcosis quistica en perros, establecimientos ganaderos y poblaciones humanas en la Provincia de Rio Negro

La vigilancia de la equinococcosis quística para detectar infestación por Echinococcus granulosus en la Provincia de Río Negro en el período 1980-2002 fue efectuada en el hombre mediante encuestas serológicas y ultrasonográficas en población joven, y en el perro por el test de arecolina. Dadas las limitaciones de esta técnica, se planteó suplantarla por el complejo copro ELISA Western Blot en heces caninas recolectadas del suelo. El objetivo del presente trabajo fue comparar las ventajas y limitaciones de las dos técnicas para medir la prevalencia de la infección en el perro, y evaluar la prevalencia actual de la infección en el hombre y en el perro. Elárea de trabajo comprendió 7 Departamentos endémicos con Programas de desparasitación canina sistemática (Area Programa) y 4 Departamentos no endémicos como Area Testigo. El test de arecolina se aplicó en los perros, con concurrencia voluntaria de sus propietarios (muestreo no aleatorizado). Las muestras para detección de coproantígenosfueron obtenidas de establecimientos ganaderos seleccionados en forma aleatorizada. En el hombre se determinó la prevalencia mediante tamizajes ultrasonográficos en escolares de 6 a 14 años y la incidencia por medio del sistema oficial de notificación de casos sintomáticos. Se dosificaron con arecolina 416 perros resultando 19 (5.2%) positivos en el Area Programa y ninguno positivo en el Area Testigo. Para la detección de coproantígenos se obtuvieron 748 muestras de materia fecal de 271 establecimientos ganaderos, resultando 37 muestras y 32 establecimientos (13.6%) positivos en el Area Programa y 4 muestras y 4 establecimientos (11.4%, IC: 0.3-32.3) positivos en el Area Testigo. En el Area Programa se efectuaron 7421 ecografías abdominales a escolares, detectándose 40 (0.5%) casos conimágenes compatibles con hidatidosis, mientras en el área testigo se efectuaron 1732 ecografías con 9 (0.5%) casos positivos...(AU)

The surveillance of infection for Echinococcus granulosus in the Provinceof Rio Negro during 1980-2002 included serological and ultrasonographic screening in humans and arecoline testin dogs. In lieu of the limitations of the arecoline test the proposal was to supplant that test for the copro Elisacopro/Western Blot complex applied to feces collected from the environment. The objective was to compare the pros and cons of the two tests and to evaluate the human and the canine infection prevalence. The working area encompassed 7 Departments with systematic canine parasiticide activities (Program Area) and 4 Departments, not endemic, as Control Area. The arecoline test was applied to the dogs in assembled groups with the voluntary participation of their owners (not randomized sampling). Samples for the detection of coproantigens were obtained from sheep farms selected at random and analyzed by the complex copro-LISA /Western Blot. Prevalence inman was determined by screening the school population (6 to 14 years old) by ultrasound, and by means of the compulsory notification of cases from the official system. Dogs (416) were tested with arecoline, 365 of whichbelonged to the Program Area. Of these 19 (5.2%) resulted positive, while none of 51 dogs from the Control Areawere positive. Samples (748) of feces were tested to detect coproantigens, obtaining 37 positive samples withinthe Program Area and 4 within the Control Area. Farms (271) from the livestock estate unit were evaluated, outof which 236 belonged to the Program Area, gave 32 (13.6%) positive results, while 4 (11.4%) of 35 from theControl Area resulted positive. Sonography tests (7421) were done in the Program Area detecting 40 (0.5%)carriers, while in the Control Area, over 1732 tests, 9 (0.5%) resulted positive...(AU)

Diagnosis of cystic echinococcosis on sheep farms in the south of Argentina: areas with a control program.

In 2000 Guarnera et al. proposed using ELISA in canine faeces collected from the ground to detect dogs infected with Echinococcus granulosus, thus determining sheep farms with active transmission. The objective was to evaluate the prevalence of E. granulosus infection in sheep farms of the Patagonia. Sheep farms were randomly selected in the Provinces of Río Negro, Chubut, Neuquén, Santa Cruz and Tierra del Fuego (areas with control programs) and La Pampa (comparison area). From one to three samples of fecal matter were obtained for each sheep farm, which were processed by means of copro-ELISA test with confirmation of positive samples by copro-Western blot. A total of 1042 samples were obtained from 352 sheep farms, 26 (7.3%) proving positive. Of these 5 (6.3%) were from La Pampa, 9 (13.8%) from Neuquén, 4 (4.7%) from Río Negro, 2 (2.9%) from Chubut, 1 (5.9%) from Santa Cruz and 5 (13.9%) from Tierra del Fuego. The identification of parasitized dogs is an essential activity upon which rests the strategy of control and surveillance. Arecoline tests or coproantigen test with fecal matter obtained directly from the dog contribute information on individual prevalence, while the use of coproantigens detected in ground-collected samples transfers the dog unit of observation to units of greater epidemiological value. In the present experience, the technique employed seems promising for its application in systems of epidemiological surveillance of cystic echinococcosis and in drawing a baseline on which to measure the progress of control programs in the Argentine Patagonia in subsequent years.

Ultrasonographic diagnosis and medical treatment of human cystic echinococcosis in asymptomatic school age carriers: 5 years of follow-up.

Hydatidosis or cystic echinococcosis (CE) caused by Echinococcus granulosus is endemic in the Province of Río Negro, Argentina. The objective of this investigation was to evaluate the results of a program carried out in endemic areas of the Province of Río Negro, Argentina, in the years 1997-2002. Abdominal ultrasonography was used, classifying the cases detected according to WHO guidelines. A treatment algorithm was defined which included observation, albendazol therapy, PAIR or surgery, according to cyst type and size. A total of 5745 schoolchildren were evaluated, detecting hydatid cyst carriers in 70 (1.2%). Of these; 40 (57.1%) were included in follow-up protocol, 25 (35.7%) in treatment protocol with albendazol, 2 (2.9%) with PAIR and 3 (4.3%) with conventional surgery. After a mean of 44 months, among 25 cases treated with albendazol, in 2 (8%) cysts underwent total involution, in 17 (68%) they presented positive changes, in one (4%) they remained unchanged and in 4 (16%) they progressed to type II, while 1 (4%) displayed negative evolutionary changes. Out of 39 cases under observation alone protocol, in 8 cases (21%) cysts underwent total involution, in 7 (18%) they presented positive changes, in 11 (28%) they remained unchanged, in 2 (5%) they progressed to Type II and in 11 (28%) they presented negative evolutionary changes and had to be included in the other protocol types. In this study, conventional surgery, was applied to 10% of detected cases. The combination of ultrasonographic screening and albendazol treatment showed promising results.

[Surveillance of foodborne diseases in the province of Rio Negro, Argentina, 1993-2001]. / Vigilancia epidemiológica de enfermedades transmitidas por alimentos en la Provincia de Río Negro, Argentina, 1993-2001.

A total of 39 outbreaks of foodborne diseases affecting 958 people in the province of Rio Negro, Argentina between 1993 and 2001 are described and evaluated. The main causal agents were identified involving food, sites of occurrence, risk factors and notification system used. Salmonella spp (38%), Trichinella spiralis (15%), Escherichia coli (13%) and Staphylococcus aureus (15%) were the most frequent agents present in outbreaks. Salmonella spp produced the largest number of cases (52%). Food involved were cooked meat (36%), cheese (10%), sandwiches (10%), deserts (10%) and ice cream (8%). Indeed, ice creams were involved in the largest number of cases and of people affected. In relation to the source of food, 41% of outbreaks were caused by homemade meals, 23% by catering or ice cream parlor, 13% in family parties, 8% in county fairs and 8% in hotel restaurants. In 28% of the outbreaks the etiological agent was identified exclusively by epidemiological analysis, in 64% isolation of the agent was carried out, and in 8% of the cases, a final diagnosis could not be obtained. Validity of epidemiological studies in foodborne disease, the necessity of strengthening the notification system of outbreaks, and the importance of good practices in food handling are analyzed.

Vigilancia epidemiológica de enfermedades transmitidas por alimentos en la Provincia de Río Negro, Argentina, 1993-2001. / [Surveillance of foodborne diseases in the province of Rio Negro, Argentina, 1993-2001]

A total of 39 outbreaks of foodborne diseases affecting 958 people in the province of Rio Negro, Argentina between 1993 and 2001 are described and evaluated. The main causal agents were identified involving food, sites of occurrence, risk factors and notification system used. Salmonella spp (38

), Trichinella spiralis (15

), Escherichia coli (13

) and Staphylococcus aureus (15

) were the most frequent agents present in outbreaks. Salmonella spp produced the largest number of cases (52

). Food involved were cooked meat (36

), cheese (10

), sandwiches (10

), deserts (10

) and ice cream (8

). Indeed, ice creams were involved in the largest number of cases and of people affected. In relation to the source of food, 41

of outbreaks were caused by homemade meals, 23

by catering or ice cream parlor, 13

in family parties, 8

in county fairs and 8

in hotel restaurants. In 28

of the outbreaks the etiological agent was identified exclusively by epidemiological analysis, in 64

isolation of the agent was carried out, and in 8

of the cases, a final diagnosis could not be obtained. Validity of epidemiological studies in foodborne disease, the necessity of strengthening the notification system of outbreaks, and the importance of good practices in food handling are analyzed.

Seroprevalencia de hantavirus en roedores y humanos en el sur de la Argentina / Hantavirus seroprevalence in rodents and human cases in southern Argentina

En la Provincia de Rio Negro, Argentina, se presentaron casos humanos de síndrome pulmonar por hantavírus (SPH) en la región de la cordillera andino paragónica. El virus Andes há sido identificado en la región, tanto en el roedor Oligoryzomys longícaudatus como en seres humanos, demostrándose la transmisión principalmente del roedor al hombre y la factibilidad de la transmisión de persona a persona. El objetivo del presente trabajo es presentar nueva información sobre especies de roedores portadores de hantavirus en Argentina, su prevalencia de anticuepos para hantavirus (período 1999-2001) y la relación del tamaño de las poblaciones de roedores y su seroprevalencia com la ocurrencia de casos humanos (período 1996-2001). Para ello, se procedió a la colocación de 3973 trampas para captura viva de roedores, tipo sherman en seis operativos efectuados entre octubre de 1999 y mayo de 2001. Se obtuvieron muestras de sangue de los roedores las que fueron procesadas mediante enzimoinmunoensayo com antígenos elaborados a partir de virus Andes. Una síntesis de los resultados indica 397 roedores capturados, com un éxito de trampeo del 10 por cento y una prevalencia de anticuerpos contra hantavirus del 1.0por cento. Se observaron importantes diferencias en las especies capturadas en cada una de las regiones. Se capturaron O longicaudatus y A Olivaceus seropositivos y A flavescens y C. Laucha potencialmente portadores de hantavirus. Se registraron 6 casos humanos en el período 1993-1995 (correspondientes a estudios retrospectivos), 21 casos se notificaron en el período 1996-1998 y 6 en el período 1999-2001. Se analiza la correlación entre ocurrencia de casos humanos, seroprevalencia en roedores y éxito de trampeo

Portadores asintomaticos de hidatidosis : epidemiologia, diagnostico y tratamiento / Asymptomatic carriers of hydatidosis : epidemiology, diagnosis and treatment

Hasta hace poco tiempo, la hidatidosis se consideraba un estado patologico de resolucion exclusivamente quirurgica. Sin embargo, en los ultimos anos se ha avanzado en los campos de la epidemiologia, el diagnostico y el tratamiento de la enfermedad y la nueva informacion aportada sobre la historia natural de la hidatidosis ha permitido definir nuevos criterios de atencion. Ahora se sabe que hasta 67 por ciento de los portadores no sintomaticos de quistes hepaticos mantienen esa condicion durante toda la vida. Esta situacion genera resultados especiales en el inmuno-diagnostico. Asi, la inmunoadsorcion enzimatica (ELISA) rinde una sensibilidad de 63 por ciento y una especificidad de 97 por ciento en portadores asintomaticos, mientras que la doble difusion cinco (DD5) tiene una sensibilidad de solo 31 por ciento en esos portadores. Por otra parte, los estudios por imagenes basados en la ecografia se han transformado en el metodo de eleccion para detectar a los portadores no sintomaticos. Son de 49 a 73 por ciento mas sensibles que la serologia e incluso pueden utilizarse como parte del sistema de vigilancia epidemiologica y del monitoreo de programas de control. Tambien se han modernizado los esquemas de intervencion. El tratamiento quimioterapico de portadores asintomaticos con albendazol produce hasta 69 por ciento de respuestas favorables mientras que los tratamientos quirurgicos minimamente invasores como la puncion-aspiracion-inyeccion-reaspiracion (PAIR) producen una reduccion del volumen medio del quiste de hasta 66 por ciento. Estos factores han permitido instaurar un protocolo de tratamiento para portadores asintomaticos en los servicios hospitalarios de la Provincia de Rio Negro, Argentina. Este se basa en el seguimiento de los quistes pequenos (tipo Ia de la escala de Gharbi modificada), tratamiento inicial con albendazol y con PAIR si no hay respuesta, en los quistes de mayor tamano o complejidad (tipos Ib, II y III), y seguimiento de los quistes no vitales o muertos (tipos IV y V)

Portadores asintomaticos de hidatidosis: epidemiologia, diagnostico y tratamiento / Asymptomatic carriers of hydatidosis: epidemiology, diagnosis and treatment

Hasta hace poco tiempo, la hidatidosis se consideraba un estado patologico de resolucion exclusivamente quirurgica. Sin embargo, en los ultimos anos se ha avanzado en los campos de la epidemiologia, el diagnostico y el tratamiento de la enfermedad y la nueva informacion aportada sobre la historia natural de la hidatidosis ha permitido definir nuevos criterios de atencion. Ahora se sabe que hasta 67 por ciento de los portadores no sintomaticos de quistes hepaticos mantienen esa condicion durante toda la vida. Esta situacion genera resultados especiales en el inmuno-diagnostico. Asi, la inmunoadsorcion enzimatica (ELISA) rinde una sensibilidad de 63 por ciento y una especificidad de 97 por ciento en portadores asintomaticos, mientras que la doble difusion cinco (DD5) tiene una sensibilidad de solo 31 por ciento en esos portadores. Por otra parte, los estudios por imagenes basados en la ecografia se han transformado en el metodo de eleccion para detectar a los portadores no sintomaticos. Son de 49 a 73 por ciento mas sensibles que la serologia e incluso pueden utilizarse como parte del sistema de vigilancia epidemiologica y del monitoreo de programas de control. Tambien se han modernizado los esquemas de intervencion. El tratamiento quimioterapico de portadores asintomaticos con albendazol produce hasta 69 por ciento de respuestas favorables mientras que los tratamientos quirurgicos minimamente invasores como la puncion-aspiracion-inyeccion-reaspiracion (PAIR) producen una reduccion del volumen medio del quiste de hasta 66 por ciento. Estos factores han permitido instaurar un protocolo de tratamiento para portadores asintomaticos en los servicios hospitalarios de la Provincia de Rio Negro, Argentina. Este se basa en el seguimiento de los quistes pequenos (tipo Ia de la escala de Gharbi modificada), tratamiento inicial con albendazol y con PAIR si no hay respuesta, en los quistes de mayor tamano o complejidad (tipos Ib, II y III), y seguimiento de los quistes no vitales o muertos (tipos IV y V)