The genus Salmonella has more than 2,600 serovars, and this trait is important when considering interventions for Salmonella control. Bacteriophages that are used for biocontrol must have an ...exclusively lytic cycle and the ability to lyse several Salmonella serovars under a wide range of environmental conditions. Salmonella phages were isolated and characterized from 34 backyard production systems (BPSs) with a history of Salmonella infections. BPSs were visited once, and cloacal or fecal samples were processed for phage isolation. Four hosts, Salmonella serovars Enteritidis, Heidelberg, Infantis, and Typhimurium, were used for phage isolation. The host range of the phages was later characterized with a panel of 23 Salmonella serovars (serovar diversity set) and 31 isolates obtained from the same farms (native set). Genetic relatedness for 10 phages with a wide host range was characterized by restriction fragment length polymorphism, and phages clustered based on the host range. We purified 63 phages, and 36 phage isolates were obtained on Salmonella Enteritidis, 16 on Salmonella Heidelberg, and 11 on Salmonella Infantis. Phages were classified in three clusters: (i) phages with a wide host range (cluster I), (ii) phages that lysed the most susceptible Salmonella serovars (serogroup D) and other isolates (cluster II), and (iii) phages that lysed only isolates of serogroup D (cluster III). The most susceptible Salmonella serovars were Enteritidis, Javiana, and Dublin. Seven of 34 farms yielded phages with a wide host range, and these phages had low levels of genetic relatedness. Our study showed an adaptation of the phages in the sampled BPSs to serogroup D Salmonella isolates and indicated that isolation of Salmonella phages with wide host range differs by farm. A better understanding of the factors driving the Salmonella phage host range could be useful when designing risk-based sampling strategies to obtain phages with a wide lytic host range for biocontrol purposes.
Eggs are the main product generated from backyard poultry production systems (BPS) because they can quickly be consumed and sold to meet essential family needs. Nevertheless, antimicrobial residues ...can accumulate in this product. The objective of this study was to evaluate the presence of antimicrobial residues in eggs produced by poultry kept in BPS in central Chile. To assess this, eggs were obtained from 83 BPS and analysed to evaluate the presence of antibiotic residues (families: tetracyclines, beta-lactams, aminoglycosides and macrolides), using a Four-Plate Test screening method for the detection, based on a bacterial growth inhibition method. Results show a lack of biosecurity procedures at BPS level, making these systems susceptible to the dissemination of antimicrobial residues. These include intensive animal production units in the proximity, and the presence of shared watercourses with other farms. Furthermore, 66% of the surveyed owners are indicated as giving pharmacological treatments to their chickens. Eggs from 61 BPS were positive for at least one antimicrobial. Fifty-three BPS were positive for more than one antimicrobial, and one BPS was positive for all four antimicrobials tested. Consequently, there is a risk that poultry eggs produced in BPS in central Chile carry residues of different families of antimicrobials.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Although wild birds are considered the main reservoir of the influenza A virus (IAV) in nature, empirical investigations exploring the interaction between the IAV prevalence in these populations and ...environmental drivers remain scarce. Chile has a coastline of more than 4000 kilometres with hundreds of wetlands, which are important habitats for both resident and inter‐hemispheric migratory species. The aim of this study was to characterize the temporal dynamics of IAV in main wetlands in central Chile and to assess the influence of environmental variables on AIV prevalence. For that purpose, four wetlands were studied from September 2015 to June 2018. Fresh faecal 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 was built to assess the association between IAV prevalence and explanatory variables. An overall prevalence of 4.28% ± 0.28% was detected with important fluctuations among seasons, being greater during summer (OR = 4.87, 95% CI 2.11 to 11.21) and fall (OR = 2.59, 95% CI 1.12 to 5.97). Prevalence was positively associated with minimum temperature for the month of sampling and negatively associated with water body size measured two months before sampling, and NDVI measured three months before sampling. These results contribute to the understanding of IAV ecological drivers in Chilean wetlands providing important considerations for the global surveillance of IAV.
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
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.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Little is known about the prevalence of avian influenza viruses (AIV) in wildlife and domestic animals in Polynesia. Here, we present the results of active AIV surveillance performed during two ...sampling seasons in 2019 on Easter Island (Rapa Nui). Tracheal and cloacal swabs as well as sera samples were obtained from domestic backyard poultry, while fresh faeces were collected from wild birds. In addition to detecting antibodies against AIV in 46% of the domestic chickens in backyard production systems tested, we isolated a novel low pathogenic H6N1 virus from a chicken. Phylogenetic analysis of all genetic segments revealed that the virus was closely related to AIV's circulating in South America. Our analysis showed different geographical origins of the genetic segments, with the PA, HA, NA, NP, and MP gene segments coming from central Chile and the PB2, PB1, and NS being closely related to viruses isolated in Argentina. While the route of introduction can only be speculated, our analysis shows the persistence and independent evolution of this strain in the island since its putative introduction between 2015 and 2016. The results of this research are the first evidence of AIV circulation in domestic birds on a Polynesian island and increase our understanding of AIV ecology in region, warranting further surveillance on Rapa Nui and beyond.
Considering the interconnections between human well-being, animal welfare, and the environment, this study aimed to investigate the impacts of drought and the COVID-19 pandemic on small-scale goat ...farmers’ well-being and their perception of goats’ welfare following the One Welfare framework. Using a telephone survey, close-ended questions, and Likert scales, we assessed the impacts of drought and the COVID-19 pandemic on human well-being and animal welfare in the Coquimbo region of Chile. The DASS-21 questionnaire was used to evaluate farmers’ mental health. Goat farmers perceived the scarcity of water and food for animals as factors that negatively affected animal productivity and welfare and caused an increase in farmers’ stress levels. Farmers who had not been visited by a veterinarian showed higher levels of stress than those who received one visit during the year (M = 10 vs. 2, p = 0.025). Additionally, farmers who perceived better welfare of their animals showed lower levels of depression (rs = −0.17, p = 0.048), anxiety (rs = −0.21, p = 0.016), and stress (rs = −0.33, p < 0.001). These findings emphasize the importance of addressing farmers’ mental health and veterinary support as crucial aspects to ensure both goat welfare and farm productivity.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
While the circulation of avian influenza viruses (IAV) in wild birds in the northern hemisphere has been well documented, data from South America remain sparse. To address this gap in knowledge, we ...undertook IAV surveillance in wild birds in parts of Central and Northern Chile between 2012 and 2015. A wide diversity of hemagglutinin (HA) and neuraminidase (NA) subtypes were identified and 16 viruses were isolated including low pathogenic H5 and H7 strains, making this the largest and most diverse collection of Chilean avian IAVs to date. Unlike IAVs isolated from wild birds in other South American countries where the genes were most like viruses isolated from wild birds in either North America or South America, the Chilean viruses were reassortants containing genes like viruses isolated from both continents. In summary, our studies demonstrate that genetically diverse avian IAVs are circulating in wild birds in Chile highlighting the need for further investigation in this understudied area of the world.
Backyard production systems (BPS) are a common form of poultry and swine production worldwide. The limited implementation of biosecurity standards in these operations makes BPS a potential source for ...the emergence of pathogens that have an impact on both animal and public health. Information regarding circulation of influenza A virus (IAV) in poultry and swine raised in BPS is scarce; particularly in South American countries. The objective of this study was to estimate prevalence and seroprevalence of IAV in BPS in central Chile, identify subtype diversity, evaluate risk factors and spatial relative risk for IAV. Samples were collected from 329 BPS from central Chile. Seroprevalence at BPS level was 34.7% (95% CI: 23.1%–46.2%), 19.7% (95% CI: 9.9%–30.6%) and 11.7% (95% CI: 7.2%–16.4%), whereas prevalence at BPS level was 4.2% (95% CI: 0.0%–8.8%), 8.2% (95% CI: 0.8%–14.0%) and 9.2% (95% CI: 4.8%–13.1%), for the Metropolitan, Valparaiso and LGB O’Higgins regions, respectively. Spatial analysis revealed that central‐western area of Metropolitan region and the southern province of Valparaiso region could be considered as high‐risk areas for IAV (spatial relative risk = 2.2, p < .05). Logistic regression models identified the practice of breeding both poultry and pigs at the BPS as a risk factor (95% CI 1.06–3.75). From 75 IAV ELISA‐positive sera, 20 chicken sera had haemagglutination inhibition titres ranging from 20 to 160, and of these, 11 had microneutralization titres ranging from 40 to 960 for one or more IAV subtypes. Identified subtypes were H1, H3, H4, H9, H10 and H12. Results from this study highlight the need for further IAV surveillance programmes in BPS in Chile. Early detection of IAV strains circulating in backyard animals, especially in regions with large human populations, could have an enormous impact on animal and public health.
The objective of this study was to estimate the prevalence and seroprevalence of influenza A virus (IAV) in poultry and swine in backyard production systems (BPS) in central Chile, identify subtype diversity, and evaluate risk factors and spatial relative risk for IAV. Prevalence of IAV in BPS was 34.7% (95% CI: 23.1%–46.2%), 21.3% (95% CI: 10.1%–31.7%) and 18.4% (95% CI: 13.3%–24.2%) for the Metropolitan, Valparaiso and LGB O’Higgins regions, respectively. The central and western area of the Metropolitan region and the southern province of Valparaiso region were identified as high‐risk areas for IAV (relative risk = 2.2, p < .05). The practice of breeding both poultry and pigs at the BPS was also identified as a risk factor. Early detection of IAV strains circulating in backyard animals, especially in regions with large human populations, could have an enormous impact on animal and public health.
During the last 5 years there has been an alarming number of reports of highly pathogenic avian influenza worldwide. However, little is known about the status of this disease in South America. Chile ...has been the only country in South America where an HPAI outbreak was reported. This outbreak occurred in 2002 and was due to an H7N3 HPAI, where the most plausible hypothesis that explained the entrance of the disease to the country, had relation to migratory wild birds. Commercial poultry farms in Chile are highly integrated and have high biosecurity standards. Nevertheless, poultry backyard production systems lack biosecurity measures and are widely distributed. Since 2002 outbreak, avian influenza viruses have been identified in wild birds and different animal species kept in backyard productive systems (BPS) in Chile. The aim of this study was to simulate the possible natural history of HPAI after its introduction to BPS in central Chile and to simulate different intervention strategies. To do so, the North American Animal Disease Spread Model version 3.3 was used. The results showed that a median of 15,930 BPS would be affected if HPAI spread among BPS in central Chile, representing 97.8% of the current amount of BPS existing in study zone. Movement restrictions, pre-emptive destruction, passive surveillance, tracing of infected premises and combinations of the three, where the intervention strategies tested in the simulation model. From all the interventions simulated, movement restrictions together with increasing surveillance (through increasing passive surveillance and good tracing of infected premises) had the biggest effect, reducing the median number of infected BPS in 90.8%. However, more studies are needed to more accurately estimate local contact rates. These results can guide the official veterinary services to consider potential mechanisms to control or prevent an HPAI emergency situation.
Objetivo. Verificar la presencia del virus de la enfermedad de Newcastle (ENC) en aves de sistemas productivos de traspatio (SPT) de parte de la zona central de Chile. Materiales y métodos. Entre ...2013 y 2015, un total de 1,579 hisopados orotraqueales fueron colectados de gallinas, pavos, patos y gansos pertenecientes a 328 SPT de la zona central de Chile. En cada SPT, los hisopos colectados de aves de la misma especie fueron agrupados en el mismo tubo con medio de transporte formando un pool compuesto por no más de 5 muestras. Los pooles fueron analizados por RT-PCR a tiempo real. Resultados. De un total de 364 pooles, 6 resultaron positivos al virus de la ENC. Los pooles positivos correspondieron a gallinas de las regiones de Valparaíso (n = 1) y Libertador General Bernardo O’Higgins (n=5). Ningún pool correspondiente a pavos, patos o gansos fue diagnosticado positivo. Conclusiones. Los resultados positivos demuestran la presencia del virus de la ENC en SPT en Chile. Esto podría deberse a la circulación de cepas lentogénicas del virus transmitidas por aves silvestres o bien al contacto con cepas vacunales administradas en los planteles industriales cuyas aves vacunadas pueden finalizar como SPT.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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