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Se efectuo una busqueda bibliografica exhaustiva sobre epidemiologia, vigilancia epidemiologica y estrategias de control de Rabia variante 4 transmitida por murcielagos insectivoros. Asimismo, como estudio de caso se efectuo un estudio retrospectivo de murcielagos insectivoros capturados por vigilancia pasiva y analizados para determinar presencia de virus rabico en la Provincia de Rio Negro, Argentina. El objetivo fue actualizar la informacion sobre la epidemiologia de la rabia variante 4 y analizar la eficacia de las medidas de control habitualmente recomendadas por los servicios de salud. La revision efectuada muestra en Sudamerica solo 5 notificaciones correspondientes a caninos y felinos entre 2009 y 2019 y en relacion a las personas, se reportaron tres casos: en Chile en 1963 y 2013 y uno en Colombia en 2012. La identificacion de murcielagos insectivoros portadores de rabia varia del del 4% al 15%. Por su parte, el servicio de salud publica veterinaria del Ministerio de Salud de Rio Negro recogio murcielagos insectivoros a partir de actividades de vigilancia pasiva. Los murcielagos fueron remitidos al Laboratorio del Instituto Luis Pasteur de la ciudad de Buenos Aires para identificacion de virus rabico. Se analizaron un total de 294 quiropteros insectivoros en 26 localidades. La proporcion de infectados fue del 14,6% (IC95% 9,5-17,8) aunque sin casos en perros, gatos o personas. Los murcielagos insectivoros pueden ser un factor de riesgo para caninos, felinos y seres humanos, aunque las notificaciones de casos a variante 4 en estas especies es extremadamente bajo en America del Sur por lo que parece requerirse una evaluacion de la estrategia de control recomendada y aplicada hasta el momento por no ser costo - efectiva, e implicar crecientes costos operativos en recursos financieros y humanos, proponiendose alternativas mas eficientes de control de riesgos.

Cystic echinococcosis (CE) is a zoonosis caused by species of the complex Echinococcus granulosus, sensu lato in their larval stage. It is an endemic disease in the province of Río Negro, where small farmers generally have both sheep and goats. Lamb vaccination with EG95 was incorporated in 2009 with very good results: in fact, it contributed to a significant drop in prevalence of infection in both sheep and goats, when determined by necropsy and serology in 2018. In the design of the activity, it was decided not to vaccinate goats in order to minimize the operational requirements of vaccination and comments from producers about the rarity of observing hydatid cysts in goat viscera were considered.To identify causes which can still generate infection in dogs, and to detect species/genotypes in circulation in the province of Río Negro.In indigenous reserves comprised within the area of lamb vaccination with 3 doses of EG95, (dose 1 in December, dose 2 in January and dose 3 in December of the year following, at the time of application of dose 1 to the new lambs). Prevalence in adult goats and sheep was determined by necropsy and serology (ELISA). Infective species/genotypes present in the work area and in the rest of the province of Río Negro were identified by Cox1 mitochondrial gene sequencing. Epidemiological analysis was completed with surveys among farmers about slaughter habits for human consumption.Through serology and necropsy, infection rates in vaccinated and nonvaccinated sheep were significantly different (21% versus 66%). Non-vaccinated sheep and non-vaccinated goats were also significantly different in that there was less infection in goats compared to sheep (7% versus 66% for necropsy, 30% versus 61% for serology); After many years of sheep vaccination the infection positives were low, and differences between vaccinated sheep and non-vaccinated goats turned out non-significant (21% versus 7%). With reference to epidemiology and control along the period 2018-2022, PZQ dosing of dogs 4 times a year was maintained, and 2 extra deworming tasks were introduced together with dose 1 and 2 of EG95, performed by the veterinary vaccination team, ensuring the ingestion of PZQ by dogs. Assessment of animal slaughter for consumption in 41 producers showed that 21 of them slaughter a monthly average of 18 goats (an average of 0.43 goat per month per farm) and 36 in all slaughter 35 old sheep in a year (average of 0.85 sheep per month per farm). With respect to identification of species/genotypes as from 2010, genotypes G1 have been found in 11 sheep (out of which 6 belong to vaccination zone) and genotypes G7, in one pig. A goat cyst within vaccination zone turned out unfertile and it was not possible to sequence it.Design and implementation of a vaccine programme combined with the use of PZQ resulted as cost-effective, since it was possible to maintain the vaccine over time, with clear impact on prevalence decrease in sheep and goats.

Human and dog health are inextricably linked, and although our relationship with dogs brings numerous benefits for our well-being, it is known that they can transmit disease. Bariloche is a Patagonian tourist city with heterogeneous social composition. This cross-sectional study evaluates the population of free-roaming dogs and their intestinal parasites in relation to the socioeconomic level of the city's human population. Census areas were used as survey units, stratified in three levels according to socioeconomic status. The free-roaming dog population was estimated by walking around each census area. Eight fresh feces per census count area were collected and analyzed using coproparasitological flotation tests, and CoproELISA was used to detect Echinococcus sp. A total of 858 free-roaming dogs were registered along 40.9 km, with significant differences between socioeconomic strata: the highest numbers were found in the lowest income strata. Of the feces collected, 39.2% tested positive for parasites, those associated with a lower socioeconomic level having higher percentages of positive feces and a greater number of species. Eight species of helminths were found, some of which were zoonotic, such as Echinococcus sp., Toxocara canis, and Dibothriocephalus latus. The presence of parasites can be explained by the number of free-roaming dogs per census count area. The free-roaming dogs generally have owners, and their parasitic infection is strongly associated with the socioeconomic level of the population. The main problem is irresponsible pet care, which generates healthy conditions for both dogs and humans. Thus, both dogs and humans deserve effective ethical public policies.

Cystic echinococcosis (CE) is endemic in the Rio Negro province of Argentina. After 30 years of control using praziquantel in dogs the transmission rate to humans and sheep has decreased significantly, however transmission persists. The objective of the study was to assess the inclusion of the EG95 for sheep in the control program and to determine the vaccine's operative feasibility in field conditions. An intervention study was defined in Rio Negro Province in Argentina comprising, in total, an area of 5820 Km2. Lambs received two vaccinations with the EG95 vaccine followed by a single booster injection when the animals were 1-1.5 years of age. Vaccination of lambs born into one trial site was introduced and continued for 8 years. Evidence for Echinococcus granulosus transmission was monitored before and after vaccination by coproantigen ELISA in faecal samples of dog, purgation of dogs to detect E. granulosus worms, necropsy on adult sheep and by ultrasound screening in children of 6-14 years old. 29,323 doses of vaccine were applied between 2009 and 2017, which a vaccination coverage of 80.1%/85.7% (57.3% average for fully vaccinated). Before the introduction of the vaccine 56.3% of the 6-year-old sheep were infected with E. granulosus at necropsy and 84.2% of the farms had infected sheep; 4.3% of the dogs were positive for E. granulosus infection using the arecoline test, and with coproELISA 9.6% of dog fecal samples were positive and 20.3% of the farms had infected dog.After the vaccine was introduced, 21.6% of sheep older than 6 years were found to be infected at necropsy and 20.2% of the farms were found to be infected; in dogs, 4.5% were found positive for E. granulosus using arecoline purgation and with coproELISA 3.7% of samples were positive, with 8.9% of farms having a positive dog. In 2016 only one case of E. granulosus infection was diagnosed by US screening in a 6-14 years old child. Included in the analysis are discussions of difficulties experienced in the field which affected correct vaccine administration as well as social features and practices that may impact on echinococcosis control and the EG95 vaccination program in Rio Negro. Vaccination of sheep with the EG95 vaccine provides a valuable new tool which improves the effectiveness of CE control activities. Vaccination was effective even in a difficult, remote environment where only approximately half the lambs born into the communities were fully vaccinated.

Background Rio Negro Province is endemic for cystic echinococcosis (CE). A CE control program includes early diagnosis in humans. During 1980-1996, screening was done with serology and surgery was the unique choice of treatment. Since 1997, ultrasound (US) has been the method of choice for screening, and new choices of treatment for asymptomatic carriers are discussed in the CE guidelines. Methods Between 1997 and 2016, 42 734 abdominal USs were performed, 192 new asymptomatic cases were diagnosed and underwent a protocol according to the size, location and type of cyst. Treatment options included active surveillance (US monitoring, 83 [43.3%]), antiparasitic (albendazole, 92 [47.9%]) and surgery (17 [8.8%], including percutaneous treatment). Results After 7.7 y of follow-up, of the cases under active surveillance, 28 (33.7%) had to change treatment: 5 (6%) to surgery and 22 (26.5%) to albendazole. Of the patients treated with albendazole, 3 (3.2%) were operated on and 13 (14%) were treated with a second cycle of albendazole. Conclusion As a result of the present study, resolution of CE in a non-surgical way with albendazole is confirmed to be effective in asymptomatic carriers with CE1 or CE3a cysts. An update eliminates the strategy of active surveillance in type CE1 cysts

Mujer pionera en el estudio del gobierno de las organizaciones y precursora de enfoques de gestión aún en desarrollo

Cystic echinococcosis is endemic in the Rio Negro province of Argentina and, for this, a control program using praziquantel in dogs was developed from 1980. The transmission rate to humans and sheep has decreased significantly, however transmission persists. In 2009 the vaccination of sheep with EG95 was incorporated in some areas of the province. The objective of the study was to evaluate the humoral responses to the vaccine EG95. Lambs received two vaccinations with the EG95 vaccine followed by a single booster injection when the animals were 1-1.5 years of age. Blood samples from 6 vaccinated groups and 4 no vaccinated sheep were obtained for determination of antibody titles against EG95 protein. Anti-EG95 responses were determined as described by Heath and Koolaard, 2012. Responses were evaluated from 331 animals. Median ELISA absorbance values in vaccinated group was 0.828, and in non-vaccinated groups was 0.218. EG95 antibody responses in sheep from different cohorts of non-immunized control groups and vaccinated groups reveal the sustained increase in response seen in animals following the third immunization. (p< 0.0001). Significant differences are also evidenced in ANOVA test (p< 0.001). An anti-EG95 antibody response was induced in all groups of immunized sheep, 4 times higher (0.828) than the mean observed in the control groups (0.218). Data described here indicate that following a third vaccination with the EG95 vaccine at 1 year of age the specific IgG responses detected in the serum of sheep increased to a level greater than that seen following the second immunization and that this response was maintained longitudinally over time, for at least 5 years. Fil: Larrieu, Edmundo Juan. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; Argentina. Universidad Nacional de Río Negro; Argentina Fil: Poggio, Thelma Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología ; Argentina Fil: Mujica, Guillermo. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Gauci, Charles G.. University of Melbourne; Australia Fil: Labanchi, Jose Luis. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Herrero, Eduardo. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Araya, Daniel. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Grizmado, Claudia. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Calabro, Arnoldo. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Talmon, Gabriel. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Crowley, Pablo Ernesto. Universidad Nacional de Río Negro; Argentina Fil: Santillán, Graciela. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Departamento de Parasitología; Argentina Fil: Vizcaychipi, Katherina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Departamento de Parasitología; Argentina Fil: Seleiman, Marcos. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Sepulveda, Luis. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: Arezo, Marcos. Provincia de Río Negro. Ministerio de Salud; Argentina Fil: García Cachau, Mariela Alejandra. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; Argentina Fil: Lamberti, Roberto. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; Argentina Fil: Molina, Leonardo. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; Argentina Fil: Gino, Lilia Mabel. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; Argentina Fil: Donadeu, Meritxell. University of Melbourne; Australia Fil: Lightowlers, Marshall W.. University of Melbourne; Australia

Cystic echinococcosis (CE) is a parasitic zoonosis caused by Echinococcus granulosus. The control program of CE of Rio Negro province, Argentina, involves annual surveillance using ultrasound (US) screening in school children, and five-year cross-sectional surveys to detect livestock farms with parasitized dogs by coproELISA with confirmation tests (Western Blot or PCR). Control program is based on deworming of dogs with praziquantel and the aim is to identify areas at risk of Cystic echinococcosis transmission to humans, using all available data sources. The information was spatially distributed in 13 program areas and, at a smaller geographical scale, in 80 Primary Health Care Centers. CoproELISA surveys involved three randomized sampling periods (2003-05, 2009-10, 2017-18), with 1790 canine fecal samples. The US surveys were conducted in 2003-08, 2009-16 and 2017-18 in 34,515 children. Heat maps were created at the smallest geographic scale with QGIS 3.4.6. For the consecutive sampling periods, prevalence of positive canine fecal samples from livestock farms were 14.7, 12.1 and 7.8%, respectively, and children prevalence was 0.4, 0.2 and 0.1%, respectively. The study has been developed on a scale according to which the temporal-spatial distribution of CE allows to adjust control strategies in those areas of potential transmission of the zoonosis to humans.

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.

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.

Immunodiagnosis in sheep presents problems of sensitivity and specificity, limiting its applicability in surveillance systems. The objective of this study was to develop a sensitive, specific and accessible technique for diagnosing cystic echinococcosis in naturally infected sheep and to evaluate the validity of necropsy as a reference test. A total of 247 sheep were studied at slaughterhouses, confirming the parasitological diagnosis with histology. Serum was processed with enzyme immunoassay (EIA) using three antigen preparations: total hydatid liquid (LHT), purified fraction of LHT (S2B) and purified lipoprotein (B). Western Blot (WB) was used as a control. EIA proved effective for differentiating Echinococcus granulosus from larval stage of Taenia hydatigena and intestinal cestodes in all three antigen preparations. Serums from macroscopically negative sheep were reactive to EIA and positive with WB. In the whole flock, sensitivity was 89.2% for LHT, 80.0% for S2B and 86.4% for B. Sensitivity in lambs was 78.6% for LHT, 75.0% for S2B and 64.3% for B. Macroscopic diagnosis at the time of slaughter was found to have limitations as a reference test for immunodiagnosis of cystic equinococcosis in sheep, so it was necessary to include histology and WB as reference tests. LHT was the antigen preparation of greatest value and EIA proved to be a sensitive and specific technique, adequate for surveillance systems and for evaluating control programmes.

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. El área 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 coproantígenos fueron 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 con imágenes compatibles con hidatidosis, mientras en el área testigo se efectuaron 1732 ecografías con 9 (0.5%) casos positivos. El test de arecolina aportó información de la prevalencia individual mientras que la detección de coproantigenos permitió mejorar la calidad de la información identificándose establecimientos donde concentrar acciones de control. El estudio permitió identificar nuevas áreas de transmisión.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.

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.

La medecine fondee sur la preuve et la gestion des connaissances sont deux apports importants qui ont un fort impact sur la prise de decisions cliniques et l'enseignement de la medecine. L'A. presente un service de bibliotheque virtuelle ou electronique cree par la bibliotheque de l'Hopital Universitaire du 12 Octobre a Madrid, afin que les utilisateurs, professionnels de la sante, accedent facilement a l'information, et pour creer une voie de communication entre eux et les bibliothecaires de facon a faire circuler dans les deux sens informations, problemes et solutions. L'article decrit la structure, les fonctionnalites et les services du portail Biblioteca Virtual, qui contient toutes les activite propres a une bibliotheque et constitue un outil puissant de gestion des contenus.

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.

Cystic echinococcosis (CE) is an endemic disease in the province of Río Negro, Argentina. The control program against CE has developed monitoring surveillance systems. Currently, the coproELISA/Western blot (WB) test is used to determine transmission in livestock farms (epidemiological units or EU) from collected dry field-dispersed dog feces. The objective was to evaluate the prevalence of CE on livestock farms and its relationship with CE cases in children aged 0-14 years. Canine fecal samples were obtained from randomly selected livestock farms and processed by the coproELISA/WB test. Furthermore, new cases in children in the same age group mentioned above were identified. In 278 EU, 571 samples of canine feces were obtained. There were 37 positive samples for coproELISA/WB (6.5%) and the presence of transmission was demonstrated in 37 EU (13.3%). There were no significant differences (p=0.9) with the survey conducted in the period 2003-2004 while there were significant differences (p=0.02) with the EU survey of native populations conducted in 2009-2010. With respect to animal density in the work area, the EU yielding negative results had an average of 2 dogs (SD 2.1) per EU while in the EU having positive results the average was 3 dogs (SD 4.2), showing statistically significant differences (p=0.02). In children under 15 years of age, 12 cases were diagnosed. This study has identified, on average, that the cases of hydatid disease are closer in the positive fields than in the negative fields (p=0.00307).The coproELISA/WB test allowed to identify the dispersion of CE on livestock farms and its relationship with the occurrence of cases in children in 2009-2010.

In this work, the impact of a hydatidosis control programme for dogs on the intermediate ovine host was specifically analysed to determine the levels of prevalence achieved and the dynamics of parasite transmission, as well as to evaluate the quality of diagnostic systems in slaughterhouses. A field study was conducted in four slaughterhouses (Valcheta, Los Menucos, Jacobacci, Bariloche) that process animals coming from all the departments within the work area. The control programme for dogs entailed treating dogs with 5 mg/kg praziquantel at 2-month intervals for 20 years. Sample size was determined with a 10% error margin and a 95% significance level. Harvested viscera (liver, lungs, kidneys) were preserved in 5% formaldehyde and sent to the laboratory for diagnostic confirmation of both positive and negative specimens. The 61% initial prevalence dropped to 18.3% at the end of the 10-year period, observed differences proving significant (Chi-square=15.454, P=0.00). There were statistically significant increases in infection prevalence with age (Pearson’s Chi-square=133.61, P=0.00). Overall, 37.2% of hydatidosis cases diagnosed in slaughterhouses were considered non-hydatid by histological study. On the other hand, 1.1% of those diagnosed as healthy were found to be infected with hydatidosis. The number of hydatid cysts per animal increased with age: 0.04 in lambs and 1.22 in adults (linear regression equation, −0.0539+0.0127×age), whereas the average for the whole period was 3.7% in lambs and 20.5% in adults. Viability studies indicated that 63.8% of parasitised animals had viable cysts, out of which 53.3% were fertile. Diagnosis of infection in sheep made by means of an adjusted statistical design and with histological confirmation of the presumptive diagnosis made in slaughterhouses demonstrated the flaws of the official systems for epidemic surveillance of hydatidosis. However, there was no overall significant difference in slaughterhouse and laboratory data. Ro was 0.53 and could imply a decrease in reproductive capacity of the parasite and steady state extinction.

The isozymes CYP1A2, CYP2D6, and CYP3A4/5 are involved in the majority of all cytochrome P450-mediated drug biotransformations. In this study we investigated the inhibition profiles of CYP1A2 (substrate: caffeine) CYP2D6 (substrate: dextromethorphan), and CYP3A4/5 (substrate: dextrorphan) by cimetidine, ranitidine, and the novel H2-receptor antagonist ebrotidine in human liver microsomes. The inhibitory effect of the drugs on the enzymes activities were as follows: CYP1A2: cimetidine >> ranitidine = ebrotidine; CYP2D6: cimetidine >>> ranitidine = ebrotidine; CYP3A4/5: ebrotidine > cimetidine >>> ranitidine. The inhibition of CYP3A4/5 enzyme activity by ebrotidine was competitive. To test whether the inhibitory effect of ebrotidine in CYP3A activity was also found in vivo, we analyzed the biodisposition of midazolam in 8 healthy volunteers. Midazolam biodisposition was significantly reduced when administered together with cimetidine (P < .05), whereas no significant inhibition was observed with ebrotidine or ranitidine compared with placebo. Psychomotor performance analysis revealed no significant effect of the observed reduction on midazolam biodisposition. We concluded that patients who are receiving treatment with drugs metabolized through CYP3A may experience enhanced drug effects as a result of pharmacokinetic interaction when treated concomitantly with cimetidine. In contrast, the effect of ranitidine or ebrotidine on CYP3A activity in vivo seems to have little clinical significance.

Cystic echinococcosis is endemic in the Rio Negro province of Argentina. After 30 years of control using praziquantel in dogs the transmission rate to humans and sheep has decreased significantly, however transmission persists. The objective of the study is to assess the impact of the inclusion of the EG95 vaccine for sheep in the control programme, including analysis of the vaccine's operative feasibility in field conditions. The vaccine was applied in an area comprising four communities of native people including 79 farms with 3146 lambs and 311 dogs in total. Seventy one farms were designated as control areas where no vaccinations were undertaken while vaccinations of lambs undertaken on 91 farms. Lambs received two vaccinations with the EG95 vaccine followed by a single booster injection when the animals were 1-1.5 years of age. Farm locations were defined using GPS coordinates for the houses. Evidence for Echinococcus granulosus transmission was monitored by coproantigen ELISA on samples of dog faeces, by E. granulosus-specific PCR using soil samples, and anti-E. granulosus antibody assessments in sera from 2 to 4 teeth lambs, purgation of dogs to detect E. granulosus worms and necropsy on adult sheep. Before the vaccine was introduced, 26.2% of sheep with 2-4 teeth were positive using ELISA/WB, the prevalence decreased to 7.8% at the third year following use of the vaccine. Necropsy of animals older than 6 years (not vaccinated) showed that 66.1% of animals were infected with E. granulosus. In dogs, 4% was found positive for E. granulosus using arecoline purgation and 24.7% of the farms were infected using coproELISA/WB. During the first year of vaccination 2721 lambs received the first vaccine dose and 2448 received a booster. In the second year 2138 lambs were initially vaccinated and 1745 received a booster, and 1308 animals received the third dose. During the third year 1110 lambs received the first dose from which 539 received a booster and 723 animals received the third dose. An analysis of advantages and limitations of the diagnostic techniques used and the ability of the geospatial analysis to detect risk area are included. Based in the immunodiagnostic techniques, the EG95 vaccine has been able to prevent the infection in animals up to 3 years old. Also, the difficulties in the field for the correct vaccine administration and the social features and habits that may impact on echinococcosis control are included in the analysis.

Cystic echinococcosis (CE) is a chronic, complex and neglected disease caused by the larval stage of Echinococcus granulosus. The effects of this neglect have a stronger impact in remote rural areas whose inhabitants have no chances of being diagnosed and treated properly without leaving their jobs and travelling long distances, sometimes taking days to reach the closest referral center. Background In 1980 our group set up a control program in endemic regions with CE in rural sections of Rio Negro, Argentina. Since 1997, we have used abdominopelvic ultrasound (US) as a screening method of CE in school children and determined an algorithm of treatment. Objectives To describe the training system of general practitioners in early diagnosis and treatment of CE and to evaluate the impact of the implementation of the field program. Materials and Methods In 2000, to overcome the shortage of radiologists in the area, we set up a short training course on Focused Assessment with Sonography for Echinococcosis (FASE) for general practitioners with no previous experience with US. After the course, the trainees were able to carry out autonomous ultrasound surveys under the supervision of the course faculty. From 2000 to 2008, trainees carried out 22,793 ultrasound scans in children from 6 to 14 years of age, and diagnosed 87 (0.4%) new cases of CE. Forty-nine (56.4%) were treated with albendazole, 29 (33.3%) were monitored expectantly and 9 (10.3%) were treated with surgery. Discussion The introduction of a FASE course for general practitioners allowed for the screening of CE in a large population of individuals in remote endemic areas with persistent levels of transmission, thus overcoming the barrier of the great distance from tertiary care facilities. The ability of local practitioners to screen for CE using US saved the local residents costly travel time and missed work and proved to be an efficacious and least expensive intervention tool for both the community and health care system., Author Summary Cystic echinococcosis (CE) is an important and widespread disease that affects sheep, cattle, and humans living in areas where sheep and cattle are raised. CE is highly endemic in rural sections of Rio Negro, Argentina, where our group is based. However, it requires continuous monitoring of both populations with human disease best assessed by means of ultrasound (US) screening. This is challenging in remote rural areas due to the shortage of imaging specialists. To overcome this hurdle, we set up a two-day training program of Focused Assessment with Sonography for Echinococcosis (FASE) on CE for family medicine practitioners with no previous experience in US. After the course, they were equipped with portable US scanners and dispatched to remote rural areas in Rio Negro where they screened patients, located and staged the cysts and decided on the treatment with the help of surgeons and radiologists in local tertiary care centers. The need to travel to referral hospitals for traditional surgical interventions was therefore limited to a few cases. US was instead brought to rural areas thereby extending affordable healthcare to people who would otherwise not have access to it.

The rodent Oligoryzomys longicaudatus (Bennett, 1832) (Rodentia, Cricetidae) inhabits southern forests of Argentina and Chile, a region severely affected by glaciations during the Pleistocene–Holocene periods. We evaluate here the diversity of the mitochondrial control region to characterize the genetic structure of this species from forests and bushy areas of seven populations from Argentina and four populations from Chile. Statistical analyses showed shallow haplotype trees and mismatch distributions compatible with recent range expansions. The presence of “private” haplotypes indicates that current levels of gene flow among populations of each country would be low to moderate. Significant differences in haplotype frequencies were detected between eastern and western populations, indicating that the Andes mountains would be an effective geographic barrier for gene flow despite the existing valleys that could act as corridors for dispersion. A single clade containing all the haplotypes was recovered in the phylogenetic trees, suggesting postglacial dispersion from a single refugium during the Last Glacial Maximum. The higher effective size and levels of polymorphism in populations from Chile suggest that the refugium was located in this country. The asymmetric gene flow from Chile to Argentina may reflect a recent colonization of the eastern populations.

Cystic echinococcosis is an endemic disease in the Province of Rio Negro, Argentina. Ultrasound surveys carried out in 1984 found prevalence rates of 5.6% in children between 6 and 14 years of age. Objective To describe and to evaluate the results of the strategy applied in school children by hospital services of the Province of Rio Negro with regard to diagnosis, treatment and monitoring of cystic echinococcosis and to evaluate simultaneously the results of the control program against cystic echinococcosis. Materials and methods In 1997 ultrasound was chosen to carry out population surveys and the medical treatment criteria for the detected cases were standardized. The population under study involved 5745 students in the first survey and 22,793 in subsequent studies. The detected cases were classified according to Gharbi's scheme. A treatment algorithm was defined based only on monitoring (“watch and wait”), albendazole, surgery (open or laparoscopic) or mini-invasive procedures, according to type, location and size of the cyst. Information was also obtained on cases notified to the Health System between 1980 and 2008. Results In the first survey, 70 carriers (1.2%) were detected; of these, 25 started albendazole treatment (35.7%) and only 3 (4.3%) underwent surgery. Ten years after treatment, 60.1% of 42 cases, presented Types IV and V cysts and 14.5% presented total involution of their cysts. In subsequent studies, 87 (0.4%) cases were detected, 49 of which started albendazole treatment (56.3%) and 9 underwent surgery (10.3%). The incidence rate of cystic echinococcosis cases decreased from 38 × 100,000 in 1980 to 3.7 × 100,000 in 2008. Discussion A strong decrease in cystic echinococcosis was obtained although persistent levels of transmission were maintained. The cases produced under these conditions are diagnosed by means of ultrasound surveys and are treated using a plan based on albendazole and monitoring by the Health System during a period of 10 years.

Background Cystic echinococcosis (CE) is an important zoonotic disease caused by the cestode parasite Echinococcus granulosus. It occurs in many parts of the world where pastoral activities predominate, including the Rio Negro province of Argentina. Although CE control activities have been undertaken in the western regions of Rio Negro for more than two decades, the disease continues to remain prevalent in both the human and livestock animal populations. Vaccination of animal intermediate hosts of CE with the EG95 vaccine may provide a new opportunity to improve the effectiveness of CE control measures, although data are lacking about field application of the vaccine. Aims Evaluate the impact of EG95 vaccination in sheep on the transmission of Echinococcus granulosus in a field environment. Methodology Two trial sites were established in western Rio Negro province within indigenous communities. Vaccination of lambs born into one trial site was introduced and continued for 6 years. Prior to initiation of the trial, and at the end of the trial, the prevalence of CE in sheep was determined by necropsy. Weaned lambs received two injections of EG95 vaccine, approximately one month apart, and a single booster injection one year later. Vaccination was not implemented at the second trial site. A total of 2725 animals were vaccinated in the first year. Animals from this cohort as well as age-matched sheep from the control area were evaluated by necropsy. Key results Introduction of the vaccine led to a statistically significant in the number and size of hydatid cysts in comparison to the situation prior to the introduction of the vaccine, or compared to CE prevalence in the control area where the vaccine was not applied. The prevalence of infection in the vaccinated area was also significantly reduced by 62% compared to the re-intervention level, being lower than the prevalence seen in the control area, although the difference from the control area after the intervention was not significant possibly due to limitations in the numbers of animals available for necropsy. Conclusions Vaccination of sheep with the EG95 vaccine provides a valuable new tool which improves the effectiveness of CE control activities. Vaccination was effective even in a difficult, remote environment where only approximately half the lambs born into the communities were fully vaccinated., Author Summary Hydatid disease, otherwise known as cystic echinococcosis (CE), is caused by Echinococcus granulosus. The disease is common in many pastoral areas, including parts of the Rio Negro province of Argentina, and is formally recognised by the WHO as a Neglected Tropical Disease. We undertook the first scientific evaluation of the EG95 vaccine against transmission of hydatid disease in a field situation. Sheep in remote indigenous communities of Rio Negro were vaccinated over a six year period. Young lambs received two injections of vaccine and a single booster injection as one year old sheep. A similar region acted as a control where vaccination was not implemented. Evaluation of the outcomes of vaccination revealed a significant, 62% decrease in the prevalence of hydatid infection in 6 year old sheep. Our study provides a template for the application of vaccination in future efforts to control transmission of E. granulosus and reduce the burden of human disease caused by the parasite.

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.

Immunodiagnosis in sheep presents problems of sensitivity and specificity, limiting its applicability in surveillance systems. The objective of this study was to develop a sensitive, specific and accessible technique for diagnosing cystic echinococcosis in naturally infected sheep and to evaluate the validity of necropsy as a reference test. A total of 247 sheep were studied at slaughterhouses, confirming the parasitological diagnosis with histology. Serum was processed with enzyme immunoassay (EIA) using three antigen preparations: total hydatid liquid (LHT), purified fraction of LHT (S2B) and purified lipoprotein (B). Western Blot (WB) was used as a control. EIA proved effective for differentiating Echinococcus granulosus from larval stage of Taenia hydatigena and intestinal cestodes in all three antigen preparations. Serums from macroscopically negative sheep were reactive to EIA and positive with WB. In the whole flock, sensitivity was 89.2% for LHT, 80.0% for S2B and 86.4% for B. Sensitivity in lambs was 78.6% for LHT, 75.0% for S2B and 64.3% for B. Macroscopic diagnosis at the time of slaughter was found to have limitations as a reference test for immunodiagnosis of cystic equinococcosis in sheep, so it was necessary to include histology and WB as reference tests. LHT was the antigen preparation of greatest value and EIA proved to be a sensitive and specific technique, adequate for surveillance systems and for evaluating control programmes.

El tratamiento ortopédico prequirúrgico de la fisura palatina es un tema controvertido debido a que no está claro si los efectos estéticos son o no duraderos y a que tampoco están claros los efectos que este tratamiento produce sobre la futura oclusión. Existen diferentes modalidades de tratamiento. Se presentan dos casos clínicos tratados con la filosofía de Latham.

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.

En la Provincia de Río Negro, Argentina, se presentaron casos humanos de síndrome pulmonar por hantavirus (SPH) en la región de la cordillera andino patagónica. El virus Andes ha sido identificado en la región, tanto en el roedor Oligoryzomys longicaudatus 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 anticuerpos para hantavirus (período 1999-2001) y la relación del tamaño de las poblaciones de roedores y su seroprevalencia con 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 sangre de los roedores las que fueron procesadas mediante enzimoinmunoensayo con antígenos elaborados a partir de virus Andes. Una síntesis de los resultados indica 397 roedores capturados, con un éxito de trampeo del 10% y una prevalencia de anticuerpos contra hantavirus del 1.0%. Se observaron importantes diferencias en las especies capturadas en cada una de las regiones. Se capturaron O. longicaudatus y A. Olivaceus seropositivos y O. 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. In the Province of Río Negro, Argentina, human cases of hantavirus pulmonary syndrome (HPS) have occurred in the region of the Patagonian Andean range. The Andes virus has been identified in the region, both in the rodent Oligoryzomys longicaudatus and in human beings, demonstrating mainly transmission from rodents to human and the possibility of person-to-person transmission. The goal of this paper is to present new information on hantavirus rodent carrier species in Argentina, the prevalence of antibodies to hantavirus (1999-2001 period) and the relationship of the rodent population size and seroprevalence with the occurrence of human cases (1996-2001 period). To this end, a total of 3,973 Sherman type traps for capturing live rodents were placed in six campaigns from October 1999 to May 2001. Rodent blood samples were obtained and processed by means of enzymoimmunoassay with antigens developed from the Andes virus. A summary of results indicates 397 captured rodents, with a 10% trapping success rate and a 1.0% prevalence of antibodies to hantavirus. Considerable differences were observed in species captured in each region. Seropositive O. longicaudatus and A. olivaceus specimens, as well as potential hantavirus O. flavescens and C. laucha carriers, were captured. Six human cases were recorded during the 1993-1995 period (corresponding to retrospective studies), while 21 cases were reported in 1996-1998 and 6 in 1999-2001. The correlation between occurrence of human cases, seroprevalence in rodents and trapping success is analyzed. Fil: Larrieu, Edmundo. Secretaria de Estado de Salud, Provincia de Rio Negro; Argentina. Fil: Herrero, Eduardo. Universidad Nacional de la Pampa. Faculdad de Ciencias Veterinarias; Argentina. Fil: Cachau, Mariela Garcia. Secretaria de Estado de Salud, Provincia de Rio Negro; Argentina. Fil: Labanchi, Jose Luis. Secretaria de Estado de Salud, Provincia de Rio Negro; Argentina. Fil: Mancini, Sergio. Secretaria de Estado de Salud, Provincia de Rio Negro; Argentina. Fil: Padula, Paula. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina. Fil: Cantoni, Gustavo. Secretaria de Estado de Salud, Provincia de Rio Negro; Argentina. Fil: Cavagion, Laura. Universidad Nacional de la Pampa. Faculdad de Ciencias Veterinarias; Argentina. Fil: Alvarez, Emiliano. Universidad Nacional de la Pampa. Faculdad de Ciencias Veterinarias; Argentina. Fil: Bruni, Maria. Universidad Nacional de la Pampa. Faculdad de Ciencias Veterinarias; Argentina. Fil: Albarracin, Silvina. Secretaria de Estado de Salud, Provincia de Rio Negro; Argentina. Fil: Arellano, Odila. Secretaria de Estado de Salud, Provincia de Rio Negro; Argentina.

Hydatidosis or cystic echinococcosis (CE) caused by Echinococcus granulosus is endemic in the Province of Rio Negro, Argentina. The objective of this investigation was to evaluate the results of a program carried out in endemic areas of the Province of Rio 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.

La hidatidosis constituye un serio problema de Salud Publica en la Provincia de Rio Negro, Argentina. Los factores que han motivado esta situacion incluyen una economia rural basada en la ganaderia ovina extensiva, bajas condiciones socioculturales en una porcion importante de la poblacion rural, habitos de faenamiento domiciliario de ovinos adultos para consumo humano con entrega de las visceras resultantes del acto para consumo de los perros e infraestructura de faena en pequenas comunidades rurales altamente deficiente. Esta situacion ha promovido la instrumentacion de un programa de control basado en la desparasitacion canina sistematica con praziquantel, la vigilancia con arecolina, la educacion sanitaria, el control de faena, la legislacion y la atencion de las personas. El programa, puesto en marcha en 1980, cubrio inicialmente con acciones sistematicas 51.479 km2, alcanzandose en 1992 120,013 km2 bajo control. 11.915 canes rurales han recibido 1,870,423 comprimidos de praziquantel con coberturas que en promedio fueron del 65%. Se efectuaron 21.444 controles de materia fecal canina mediante la dosificacion con bromhidrato de arecolina, (control anual del 11,2% de los canes bajo programa). La prevalencia equinococcosica inicial era de 41,5%, siendo en 1996 del 2,9%. La hidatidosis ovina, por su parte, presenta una disminucion acentuada de la prevalencia, ubicandose en 1996 en el 5,5%. En relacion a hidatidosis humana, 1,720 casos nuevos fueron diagnosticados en toda la provincia en el periodo 1980/1996, el 31,4% de los cuales correspondieron a infectados asintomaticos, mediante encuestas serologicas o ecograficas (48.826 encuestas serologicas a poblacion escolar y a pobladores rurales adultos y 2.762 encuestas ultrasonograficas). El numero de casos humanos nuevos en el grupo de edad 0-10 anos presenta una disminucion del 77% desde la puesta en marcha del programa. Por el contrario, zonas no tratadas muestran una tendencia estable en la aparicion de casos humanos nuevos. En el periodo 1980/1986 se produjeron 581 casos nuevos en las areas bajo programa, mientras que en el periodo 1990/1996 el numero de casos nuevos fue de 275. Las encuestas ultrasonograficas en poblacion asintomatica, por su parte, arrojaron tasas de positividad del 5,5% (1984), 4,1% (1986) y 2,1% (1996). El modelo desarrollado, basado en una estructura de ejecucion descentralizada, con activa participacion comunitaria, seleccion de tecnologias sencillas y enfoque de riesgo; sustentado en el tiempo sobre la base de una firme decision politica de continuidad programatica y a su bajo costo operativo habria en tal sentido, modificado la capacidad de reproduccion del parasito.

Hydatidosis (cystic echinococcosis) constitutes a serious public health problem in the Province of Rio Negro, Argentina. In the present work it was intended to evaluate the prevalence of the canine echinococcosis in rural areas of the Province of Rio Negro and studied the reinfection rate in dogs after treatment with Praziquantel during the period 1980–1997. A total of 496 dogs were studied in 18 canine concentrations in order to establish the initial prevalence rate which was 42.3%. From 1980 onward dogs should have been systematically treated with anthelmintic every 2 months in rural areas and every 6 months in urban areas. We estimated that approximately 65% of dogs were treated. To determine the reinfection rate, 476 dogs (1984) and 598 dogs (1996) were studied after anthelmintic treatment during two sequential time periods (0–45; 46–90 days). In both cases treated animals were compared with untreated dogs. Prevalences were 3.5%, 6.7% and 21.3% in 1984 and 0.8%, 4.0% and 10.0% in 1996. For the purpose of surveillance a total number of 21,444 dogs were studied during 18 years. Prevalence of Echinococcus granulosus decreased significantly in the first year from 42.3% to 6.1%.

Person-to-person transmission should be suspected when Andes virus case-patients are linked., 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 hantavirus infection cases 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 >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.