Abstract Introduction Transanal total mesorectal excision (TaTME) has revolutionized the surgical techniques for lower-third rectal cancer. The aim of the present study was to analyze the outcomes of quality indicators of TaTME for rectal cancer compared with laparoscopic TME (LaTME). Methods A cohort prospective study with 50 (14 female and 36male) patients, with a mean age of 67 (range: 55.75 to 75.25) years, who underwent surgery for rectal cancer. In total, 20 patients underwent TaTME, and 30, LaTME. Every TaTME procedure was performed by experienced colorectal surgeons. The sample was divided into two groups (TaTME and LaTME), and the quality indicators of the surgery for rectal cancer were analyzed. Results There were no statistically significant differences regarding the patients and the main characteristics of the tumor (age, gender, American Society of Anesthesiologists [ASA] score, body mass index [BMI], tumoral stage, neoadjuvant therapy, and distance from the tumor to the external anal margin) between the two groups. The rates of: postoperativemorbidity (TaTME: 35%; LaTME: 30%; p=0.763);mortality (0%); anastomotic leak (TaTME: 10%; LaTME: 13%; p=0.722); wound infection (TaTME: 0%; LaTME: 3.3%; p=0.409); reoperation (TaTME: 5%; LaTME: 6.6%; p=0.808); and readmission (TaTME: 5%; LaTME: 0%; p=0.400), as well as the length of the hospital stay (TaTME: 13.5 days; LaTME: 11 days; p=0.538), were similar in both groups. There were no statistically significant differences in the rates of positive circumferential resection margin (TaTME: 5%; LaTME: 3.3%; p=0.989) and positive distal resection margin (TaTME: 0%; LaTME: 3.3%; p=0.400), the completeness of the TME (TaTME: 100%; LaTME: 100%), and the number of lymph nodes harvested (TaTME: 15; LaTME: 15.5; p=0.882) between two groups. Conclusion Transanal total mesorectal excision is a safe and feasible surgical procedure for middle/lower-third rectal cancer.

Abstract Introduction The Covid-19 pandemic has had an important impact on colorectal cancer surgery, for hospital resources had to be redistributed in favour of Covid-19 patients. The aim of the present study is to analyze our results in colorectal oncologic surgery during the Covid-19 pandemic in patients with and without perioperative SARSCoV- 2 infection. Methods In total, 32 patients (19 male and 13 female patients), with a mean age of 64 years (range: 57.2 to 69.5 years) with colorectal cancer underwent surgery under the recommendations of surgical societies included in a protocol. Data collection included clinical characteristics (gender, age, body mass index, American Society of Anesthesiologists score, tumor location, preoperative staging, lymphopenia), data related to SARS-CoV-2 infection (postoperative symptoms, diagnostic tests), operative details (surgical procedure, approach, duration, stoma), pathological outcomes (tumor stage, number of lymph nodes harvested, distal and circumferential radial margins, quality of the total mesorectal excision), and surgical outcomes (morbidity, mortality, hospital stay, and the rates of reoperation and readmission). Results A total of 3 (9.4%) patients who underwent colorectal surgery during the Covid-19 pandemic were infected by SARS-CoV-2 in the postoperative period. Chronic obstructive pulmonary disease was associated with Covid-19 (6.2% versus 33.3%; p=0.042), and surgical morbidity was higher among Covid-19 patients (100% versus 37.9%; p=0.039). There were not significant differences between COVID-19 patients and non-COVID-19 patients in relation to the rest of the analyzed outcomes. Conclusion During the Covid-19 pandemic, colorectal cancer surgery should be performed according to the recommendations of surgical societies. However, Covid- 19 patients could present a higher morbidity rate.

RESUMO Objetivo: Investigar como os sintomas variam de acordo com a posição do apêndice em pacientes pediátricos e demonstrar que a laparoscopia é segura e eficaz em qualquer posição do apêndice, comparando-as. Métodos: Os prontuários de 1.736 pacientes pediátricos com idade ≤14 anos submetidos à apendicectomia laparoscópica em um período de 14 anos foram analisados retrospectivamente. Os pacientes foram divididos de acordo com a posição do apêndice: anterior, pélvica, retrocecal e sub-hepático. Os testes de Kruskal-Wallis e do qui-quadrado foram usados com a correção de Bonferroni, sendo significante p<0,05. Resultados: A posição do apêndice era anterior em 1.366 casos, retrocecal em 248 casos, pélvica em 66 casos e sub-hepática em 56 casos. Não houve diferenças significativas entre os grupos quanto às variáveis idade e sexo. A dor abdominal foi a única variável com diferenças estatisticamente significantes entre os grupos. A taxa de apêndice perfurado foi superior nas posições sub-hepática e pélvica. As complicações intraoperatórias e a taxa de conversão não foram estatisticamente significativas. As dificuldades técnicas e o tempo cirúrgico foram superiores em posição sub-hepática. A taxa de complicações pós-operatórias foi semelhante entre as diferentes posições, exceto a obstrução intestinal, que foi superior em posição pélvica. Conclusões: Os sintomas da apendicite dificilmente variam com a posição do apêndice. A laparoscopia é segura e eficaz, independentemente da posição do apêndice.

ABSTRACT Objective: To investigate how symptoms vary according to the appendiceal position in pediatric patients and to demonstrate that the laparoscopic approach is safe and effective in any appendiceal location by comparing each location to another. Methods: The medical records of 1,736 children aged 14 or younger who underwent laparoscopic appendectomy over a period of 14 years were analyzed retrospectively. Patients were divided according to the position of the appendiceal tip into four groups: anterior, pelvic, retrocecal and subhepatic. The Kruskal-Wallis and chi-square tests were used with the Bonferroni correction, with a significant p<0.05. Results: The appendiceal location was anterior in 1,366 cases, retrocecal in 248 cases, pelvic in 66 cases and subhepatic in 56 cases. There were no significant differences between the groups in terms of patient age and gender. Abdominal pain was the only symptom with statistically significant differences between the groups. The rate of perforated appendicitis was higher in the subhepatic and pelvic positions. Intraoperative complications and conversions were not statistically significant. Technical difficulties and operative time were higher in subhepatic position. The rate of postoperative complications was similar between the different locations, except for bowel obstruction, which was higher in pelvic appendicitis. Conclusions: The clinical symptoms of appendicitis hardly ever change with the position of the appendix. The laparoscopic approach is safe and effective, regardless the appendiceal location.

Introduction Sclerosing encapsulating peritonitis is a chronic inflammation of the peritoneum characterized by the progressive accumulation of collagen. This leads to a thickening of the peritoneum, encapsulating loops of small bowel and causing intestinal obstruction. Case report 83 year old male, carrying a ventriculoperitoneal low pressure shunt for 8 years. The patient was admitted for emergency surgery after presentation for possible intestinal obstruction with radiological findings consistent with small bowel obstruction, probably related to the catheter of the ventriculoperitoneal shunt. Surgery confirmed bowel obstruction and a change of gauge of the terminal ileum. The small bowel was dilated into a ball, encased by a small fibrous capsule. Adhesiolysis and right hemicolectomy was performed with resection of the affected bowel segment. The pathology was consistent with sclerosing encapsulating peritonitis. Conclusions Sclerosing encapsulating peritonitis is a rare and potentially serious cause of bowel obstruction and its secondary form is usually associated with chronic peritoneal dialysis. The radiological diagnosis is difficult and the treatment of choice is surgical. We must consider it in cases of intestinal obstruction in patients with ventriculoperitoneal shunt.

Resumen Introducción La peritonitis esclerosante encapsulada es una inflamación crónica del peritoneo caracterizada por la formación progresiva de colágeno que produce un engrosamiento peritoneal que encapsula las asas del intestino delgado, produciendo una obstrucción intestinal. Caso clínico Varón de 83 años portador de catéter de derivación ventriculoperitoneal de baja presión desde hacía 8 años. Acude a Urgencias por clínica de obstrucción intestinal, con hallazgos radiológicos en relación con obstrucción de intestino delgado en probable relación con catéter de derivación ventriculoperitoneal, por lo que se decide realizar intervención quirúrgica urgente. Se confirmó la obstrucción intestinal y un cambio de calibre del íleon terminal. El intestino delgado estaba dilatado formando un ovillo, englobado por una pequeña cápsula fibrosa. Se realizó adhesiólisis y hemicolectomía derecha con resección del segmento intestinal afectado. La anatomía patológica fue compatible con peritonitis esclerosante encapsulada. Conclusiones La peritonitis esclerosante encapsulada es una causa poco frecuente y potencialmente grave de obstrucción intestinal y su forma secundaria está habitualmente asociada a la diálisis peritoneal crónica. Su diagnóstico radiológico es difícil y el tratamiento de elección es quirúrgico. Debemos considerarla en casos de obstrucción intestinal en pacientes portadores de derivación ventriculoperitoneal.

Objective: To present the second case described in the literature of biliscrotum secondary to spontaneous retroperitoneal biloma and show a sequential treatment that we provided until complete resolution. Clinical case: We report the case of a man 69 years old, who debuted with right scrotal pain related to biliscrotum secondary to spontaneous retroperitoneal biloma. Discussion: The retroperitoneal biloma is a rare event, usually due to surgical or invasive procedures complications (radiological interventionism, ERCP and endoscopic sphincterotomy), although it may be the result of spontaneous rupture of the gallbladder or bile duct. Bile in the retroperitoneum may extend into the scrotum, causing the rare condition known as biliscrotum. Usually it occurs simulating an incarcerated inguinal hernia. Does not exist a standardized management of this condition because is poorly described.

Objetivo. Presentar el segundo caso descrito en la bibliografía de bilioescroto secundario a bilioma retroperitoneal espontáneo y mostrar a su vez de manera escalonada el tratamiento que se le suministró hasta la resolución completa del cuadro. Caso clínico: Varón de 69 años que debutó con dolor escrotal derecho en relación con bilioescroto secundario a bilioma retroperitoneal espontáneo. Discusión: El bilioma retroperitoneal es un hecho poco habitual; generalmente se debe a complicaciones quirúrgicas o de procedimientos invasivos (intervencionismo radiológico, CPRE y esfinterotomía endoscópica), aunque puede ser consecuencia de roturas espontáneas de la vesícula o la vía biliar principal. La bilis en el retroperitoneo puede discurrir hasta el escroto, originando la rara entidad conocida como bilioescroto. Generalmente se presenta simulando una hernia inguinal incarcerada. No existe un manejo estandarizado de esta patología ya que está escasamente descrita.

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.

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.

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.

La equinococosis quística (EQ) es una enfermedad endémica en la provincia de Río Negro, Argentina. El programa de control de esta afección desarrolla sistemas de vigilancia epidemiológica basados en las técnicas de coproELISA/Western blot (WB) en muestras de heces de perros recolectadas del suelo, a fin de determinar establecimientos ganaderos (unidades epidemiológicas o UE) con transmisión presente. El objetivo de esta investigación fue evaluar la prevalencia de EQ en establecimientos ganaderos y su relación con la presencia de casos de EQ en niños de 0 a 14 años. Se seleccionaron aleatoriamente UE donde se obtuvieron muestras de materia fecal canina, las que fueron procesadas mediante coproELISA/WB. Asimismo, se identificaron casos nuevos ocurridos en niños del rango etario señalado. Se obtuvieron 571 muestras de 278 UE; 37 (6,5 %) fueron positivas a coproELISA/WB de 37 (13,3 %) UE con transmisión presente. Las diferencias con el relevamiento efectuado en el período 2003-2004 resultaron no significativas (p = 0,9), mientras que las diferencias con el relevamiento efectuado en UE de poblaciones originarias en 2009-2010 resultaron significativas (p = 0,02). Con relación a la densidad animal en el área de trabajo, las UE que dieron un resultado negativo tuvieron un promedio de 2 (DE: 2,1) perros por UE, en las UE con infección presente el promedio fue de 3 (DE 4,2), esta diferencia fue estadísticamente significativa (p = 0,02). Se diagnosticaron 12 casos en niños menores de 15 años. Se estableció que los casos de hidatidosis, en promedio, se situaron a menor distancia de los campos positivos a coproELISA/WB que de los campos negativos (p= 0,00307). La prueba de coproELISA/WB permitió identificar la dispersión de EQ en establecimientos ganaderos y analizar su relación con la ocurrencia de casos en niños.

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.

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.

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.

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.

Se describen 39 brotes de enfermedades transmitidas por alimentos que afectaron a 958 personas en la provincia de Río Negro, Argentina, en el período 1993- 2001. Se identifican los agentes causales, los alimentos involucrados, los sitios de ocurrencia, los factores de riesgo involucrados y los mecanismos de notificación empleados. Salmonella spp (38%), Trichinella spiralis (15%), Escherichia coli (13%) y Staphylococcus aureus (15%) resultaron los agentes más frecuentes en los brotes. Salmonella spp. también produjo el mayor número de casos (52%). Los principales alimentos involucrados resultaron cárneos (36%), quesos (10%), fiambres y sándwiches (10%), postres (10%) y helados (8%). El mayor número de casos, por su parte, fue causado por la ingestión de helados (37%). Con relación al origen de los alimentos, 41% de los brotes fueron causados por comidas elaboradas en los domicilios, 23% en establecimientos comerciales, 13% en fiestas familiares, 8% en fiestas comunitarias y 8% en restaurantes de hoteles. En el 28% de los brotes fue identificado el agente etiológico por análisis epidemiológico exclusivamente, en el 64% se logró el aislamiento del agente, mientras que en el 8% de los casos no se logró el diagnóstico definitivo. Se analiza el valor de la encuesta epidemiológica en los estudios de enfermedades transmitidas por alimentos, la necesidad de fortalecer el sistema de notificación médica de casos y brotes y la importancia de las buenas prácticas en la manipulación de alimentos.

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.

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.

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.

La hidatidosis constituye un serio problema de Salud Pública en la Provincia de Río Negro, Argentina. Los factores que han motivado esta situación incluyen una economía rural basada en la ganadería ovina extensiva, bajas condiciones socioculturales en una porción importante de la población rural, hábitos de faenamiento domiciliario de ovinos adultos para consumo humano con entrega de las vísceras resultantes del acto para consumo de los perros e infraestructura de faena en pequeñas comunidades rurales altamente deficiente. Esta situación ha promovido la instrumentación de un programa de control basado en la desparasitación canina sistemática con praziquantel, la vigilancia con arecolina, la educación sanitaria, el control de faena, la legislación y la atención de las personas. El programa, puesto en marcha en 1980, cubrió inicialmente con acciones sistemáticas 51.479 km², alcanzándose 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 dosificación con bromhidrato de arecolina, (control anual del 11,2% de los canes bajo programa). La prevalencia equinococcósica inicial era de 41,5%, siendo en 1996 del 2,9%. La hidatidosis ovina, por su parte, presenta una disminución acentuada de la prevalencia, ubicándose en 1996 en el 5,5%. En relación a hidatidosis humana, 1,720 casos nuevos fueron diagnosticados en toda la provincia en el período 1980/1996, el 31,4% de los cuales correspondieron a infectados asintomáticos, mediante encuestas serológicas o ecográficas (48.826 encuestas serológicas a población escolar y a pobladores rurales adultos y 2.762 encuestas ultrasonográficas). El número de casos humanos nuevos en el grupo de edad 0-10 años presenta una disminución del 77% desde la puesta en marcha del programa. Por el contrario, zonas no tratadas muestran una tendencia estable en la aparición de casos humanos nuevos. En el período 1980/1986 se produjeron 581 casos nuevos en las áreas bajo programa, mientras que en el período 1990/1996 el número de casos nuevos fue de 275. Las encuestas ultrasonográficas en población asintomática, 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 ejecución descentralizada, con activa participación comunitaria, selección de tecnologías sencillas y enfoque de riesgo; sustentado en el tiempo sobre la base de una firme decisión política de continuidad programática y a su bajo costo operativo habría en tal sentido, modificado la capacidad de reproducción del parásito.

Em 1995, o primeiro caso de Síndrome Pulmonar pelo Hantavírus (HPS) foi sorologicamente confirmado em El Bolsón (Província de Rio Negro, Argentina), correspondendo ao terceiro surto relatado na Argentina. Um total de 26 casos de HPS relacionados com a região Andina, Província de Rio Negro, foram relatados de 1993 a 1996, 17 em El Bolsón, 4 em São Carlos de Bariloche e 5 em Buenos Aires. O índice de incidência foi de 5,03 x 100.000 com índice de mortalidade de 51,85 x 100. A ocorrência de casos foi principalmente sasonal, com números significativamente maiores na primavera, e as pessoas afetadas viviam principalmente nas áreas urbanas e periurbanas. Em 4 casos, os indivíduos afetados eram membros de um casal, esposas ou viviam em contato. Sete casos eram trabalhadores da Saúde (médicos, enfermeiras e pessoal administrativo). Doze casos estavam relacionados entre si, devidos a um surto de 80 dias. Dois deles não visitaram a região Andina. Um total de 139 roedores foram capturados e sete deles, Olygoryzomys longicaudatus, foram sorologicamente positivos. A possibilidade de infecção por contato com roedores ou fezes está sendo analisada e também a hipótese de transmissão interhumana

Early in 1995 the first case of Hantavirus Pulmonary Syndrome was serologically confirmed in El Bolsón (Province of Río Negro, Argentina), corresponding to the third outbreak reported in Argentina. A total of 26 cases of HPS related to the Andean region of Rio Negro Province, were reported from 1993 to 1996, 17 in El Bolsón, 4 in San Carlos de Bariloche, and 5 in Buenos Aires. The incidence rate was 5.03 x 100000 with a mortality rate of 51.85 x 100. The occurrence of cases was mainly seasonal, with a significantly greater number in the spring, and the persons affected mainly lived in urban or periurban areas. In four cases, the affected individuals were members of a couple, spouses or live-in contacts. Seven cases were Health workers (physicians, nurses or administrative staff). Twelve cases were related among them, due to an outbreak of 80 days. Two of them did not visit the Andean region. A total of 139 rodents were captured and seven of them, Olygoryzomys longicaudatus, were found to be serologically positive. The possibility of infection by contact with rodents or fecal matter is being analyzed and also hypothesis related with interhuman transmission