Swine Backyard Production Systems in Central Chile: Characterizing Farm Structure, Animal Management, and Production Value Chain.

Backyard production systems (BPS) are highly distributed in central Chile. While poultry BPS have been extensively characterized, there remains a notable gap in the characterization of swine BPS in central Chile. In addition, there is evidence that zoonotic pathogens, such as influenza A virus and Salmonella spp., are circulating in backyard poultry and pigs. A total of 358 BPS located in central Chile were evaluated between 2013 and 2015 by interviewing farm owners. Severe deficiencies in biosecurity measures were observed. The value chain of swine backyard production identified food, veterinary care (visits and products), and replacement or breeding animals as the primary inputs to the backyard. The most common origin of swine replacements was from outside the BPS (63%). The main outputs of the system were identified as meat and live animals, including piglets and breeding animals. In 16% of BPS, breeding animals were lent to other BPS, indicating the existence of animals and animal product movement in and out of backyard farms. Results from this study indicate that swine BPS in central Chile represents an animal-human interface that demands special attention for implementing targeted preventive measures to prevent the introduction and spread of animal pathogens and the emergence of zoonotic pathogens.

Remote Sensing and Ecological Variables Related to Influenza A Prevalence and Subtype Diversity in Wild Birds in the Lluta Wetland of Northern Chile.

The Lluta River is the northernmost coastal wetland in Chile, representing a unique ecosystem and an important source of water in the extremely arid Atacama Desert. During peak season, the wetland is home to more than 150 species of wild birds and is the first stopover point for many migratory species that arrive in the country along the Pacific migratory route, thereby representing a priority site for avian influenza virus (AIV) surveillance in Chile. The aim of this study was to determine the prevalence of influenza A virus (IAV) in the Lluta River wetland, identify subtype diversity, and evaluate ecological and environmental factors that drive the prevalence at the study site. The wetland was studied and sampled from September 2015 to October 2020. In each visit, fresh fecal samples of wild birds were collected for IAV detection by real-time RT-PCR. Furthermore, a count of wild birds present at the site was performed and environmental variables, such as temperature, rainfall, vegetation coverage (Normalized Difference Vegetation Index-NDVI), and water body size were determined. A generalized linear mixed model (GLMM) was built to assess the association between AIV prevalence and explanatory variables. Influenza positive samples were sequenced, and the host species was determined by barcoding. Of the 4349 samples screened during the study period, overall prevalence in the wetland was 2.07% (95% CI: 1.68 to 2.55) and monthly prevalence of AIV ranged widely from 0% to 8.6%. Several hemagglutinin (HA) and neuraminidase (NA) subtypes were identified, and 10 viruses were isolated and sequenced, including low pathogenic H5, H7, and H9 strains. In addition, several reservoir species were recognized (both migratory and resident birds), including the newly identified host Chilean flamingo (Phoenicopterus chilensis). Regarding environmental variables, prevalence of AIV was positively associated with NDVI (OR = 3.65, p < 0.05) and with the abundance of migratory birds (OR = 3.57, p < 0.05). These results emphasize the importance of the Lluta wetland as a gateway to Chile for viruses that come from the Northern Hemisphere and contribute to the understanding of AIV ecological drivers.

Nicotinamide protected first-phase insulin response (FPIR) and prevented clinical disease in first-degree relatives of type-1 diabetics.

BACKGROUND: After a study of ICA prevalence among relatives of Type-1 diabetics (DM1) in Santiago, Chile, parents of those who tested positive asked us to go on forward with an intervention study. METHODS: We had screened 1021 relatives, of which 30 had shown ICA > or = 20 JDF units (2.9%). Among the 26/30 who participated in the intervention study, the baseline screening showed normal glucose tolerance in all, and the first-phase insulin response (FPIR) was normal in 24/26 individuals, which were randomized into Nicotinamide (n = 12; oral Nicotinamide, 1200 mg m(-2) day(-1)) and Placebo (n = 12) groups. The FPIRs and ICAs were monitored yearly. Compliance was monitored by urine Nicotinamide. RESULTS: The 1.5, 3.0 and 5-year life-table estimates of keeping the FPIR > or = 10th centile were, for Nicotinamide group 100% in all time points, and for Placebo these were 90.0% (c.i. = 100-71.4), 72.0% (c.i. = 100-37.1) and 0.0% (c.i. = 0.0-0.0) (p = 0.0091). The 5-year life-table estimates of remaining diabetes-free were 100% for Nicotinamide and 62.5% for Placebo (p = 0.0483). No adverse effects were observed. CONCLUSIONS: Oral Nicotinamide protected beta-cell function and prevented clinical disease in ICA-positive first-degree relatives of type-1 diabetes.

Análisis uni y multivariado de los factores pronósticos en cáncer de colon / Uni and multivariate analysis of pronostic factors in colon cancer

El objetivo de esta comunicación es evaluar la importancia de distintas variables clínicas e histopatológicas involucradas en el pronóstico de pacientes con CC. Este estudio retrospectivo incluye 308 pacientes operados con intención curativa en el período Enero 1975 a Diciembre 1996. La información fue obtenida de la base de datos computarizada y la sobrevida certificada a través de registros clínicos, entrevista telefónica y certificados de defunción. Se realizó un análisis uni y multivariado (regresión logística-Cox) para predictores de recidiva tumoral. La sobrevida fue estimada a través del método de Kaplan-Meier. La edad promedio fue de 63 (23-94) años, un 48 por ciento (149) fueron sexo masculino. La distribución de las lesiones en el colon derecho, colon transverso, colon izquierdo y sigmoides, fue de 37 por ciento (114), 8 por ciento (23), 15 por ciento (46) y 40 por ciento (124) respectivamente. Según la clasificación TNM, un 10 por ciento, 58 por ciento, 27 por ciento y 5 por ciento correspondieron a etapas I, II, III y IV respectivamente. El tiempo de seguimiento medio fue de 108 meses. La sobrevida libre de enfermedad a 5 años fue de un 73 por ciento. En el análisis univariado no se encontró significancia estadística para la edad, localización tumoral y grado de diferenciación tumoral. La invasión de la pared más allá de la muscular propia y el compromiso ganglionar, fueron los únicos factores independientes para recidiva de la enfermedad en el análisis multivariado (OR=2.9, OR=2.4 respectivamente). En conclusión, el compromiso ganglionar y la invasión de la pared son variables que predicen la recidiva de la enfermedad, por lo que se deben considerar para el uso de la terapia adyuvante.