Evolution and Current Status of Influenza A Virus in Chile: A Review.

The influenza A virus (IAV) poses a significant global threat to public health and food security. Particularly concerning is the avian influenza virus (AIV) subtype H5N1, which has spread from Europe to North and Central/South America. This review presents recent developments in IAV evolution in birds, mammals, and humans in Chile. Chile's encounter with IAV began in 2002, with the highly pathogenic avian influenza (HPAI) H7N3 virus, derived from a unique South American low pathogenic avian influenza (LPAI) virus. In 2016-2017, LPAI H7N6 caused outbreaks in turkey, linked to wild birds in Chile and Bolivia. The pandemic influenza A (H1N1) 2009 (H1N1pdm09) virus in 2009 decreased egg production in turkeys. Since 2012, diverse IAV subtypes have emerged in backyard poultry and pigs. Reassortant AIVs, incorporating genes from both North and South American isolates, have been found in wild birds since 2007. Notably, from December 2022, HPAI H5N1 was detected in wild birds, sea lions, and a human, along Chile's north coast. It was introduced through Atlantic migratory flyways from North America. These findings emphasize the need for enhanced biosecurity on poultry farms and ongoing genomic surveillance to understand and manage AIVs in both wild and domestic bird populations in Chile.

Recent Evolution and Genomic Profile of Salmonella enterica Serovar Heidelberg Isolates from Poultry Flocks in Brazil.

Salmonella enterica serovar Heidelberg is isolated from poultry-producing regions around the world. In Brazil, S. Heidelberg has been frequently detected in poultry flocks, slaughterhouses, and chicken meat. The goal of the present study was to assess the population structure, recent temporal evolution, and some important genetic characteristics of S. Heidelberg isolated from Brazilian poultry farms. Phylogenetic analysis of 68 S. Heidelberg genomes sequenced here and additional whole-genome data from NCBI demonstrated that all isolates from the Brazilian poultry production chain clustered into a monophyletic group, here called S. Heidelberg Brazilian poultry lineage (SH-BPL). Bayesian analysis defined the time of the most recent common ancestor (tMRCA) as 2004, and the overall population size (Ne) was constant until 2008, when an ∼10-fold Ne increase was observed until circa 2013. SH-BPL presented at least two plasmids with replicons ColpVC (n = 68; 100%), IncX1 (n = 66; 97%), IncA/C2 (n = 65; 95.5%), ColRNAI (n = 43; 63.2%), IncI1 (n = 32; 47%), ColMG828, Col156, IncHI2A, IncHI2, IncQ1, IncX4, IncY, and TrfA (each with n < 4; <4% each). Antibiotic resistance genes were found, with high frequencies of fosA7 (n = 68; 100%), mdf(A) (n = 68; 100%), tet(34) (n = 68; 100%), sul2 (n = 64; 94.1%), and blaCMY-2 (n = 56; 82.3%), along with an overall multidrug resistance (MDR) profile. Ten Salmonella pathogenicity islands (SPI1 to SPI5, SPI9, and SPI11 to SPI14) and 139 virulence genes were also detected. The SH-BPL profile was like those of other previous S. Heidelberg isolates from poultry around the world in the 1990s. In conclusion, the present study demonstrates the recent introduction (2004) and high level of dissemination of an MDR S. Heidelberg lineage in Brazilian poultry operations. IMPORTANCES. Heidelberg is the most frequent serovar in several broiler farms from the main Brazilian poultry-producing regions. Therefore, avian-source foods (mainly chicken carcasses) commercialized in the country and exported to other continents are contaminated with this foodborne pathogen, generating several national and international economic losses. In addition, isolates of this serovar are usually resistant to antibiotics and can cause human invasive and septicemic infection, representing a public health concern. This study demonstrates the use of whole-genome sequencing (WGS) to obtain epidemiological information for one S. Heidelberg lineage highly spread among Brazilian poultry farms. This information will help to define biosecurity measures to control this important Salmonella serovar in Brazilian and worldwide poultry operations.

Multilocus sequence typing of multidrug-resistant Salmonella strains circulating in poultry farms of Bangladesh.

Salmonella is one of the most important foodborne zoonotic pathogens, and becoming multidrug-resistant (MDR), which represents a serious public health concern worldwide. This study aimed to identify the circulating MDR strains of Salmonella through cutting edge molecular techniques including gene specific PCR, RAPD-PCR, ribosomal gene sequencing, and multilocus sequence types (MLST) in the poultry industry of Bangladesh. Two hundred Salmonella isolates were retrieved from 154 samples comprising droppings (n = 60), cloacal swabs (n = 60), feeds (n = 14), feeding water (n = 14), and handler's swab (n = 6) from 14 commercial layer farms of Bangladesh. The isolates were confirmed as Salmonella through invA gene specific PCR, and further genotyping was done by RAPD-PCR, and 16S rRNA sequencing. The isolates were distributed into 18 different genotypes according to RAPD typing. The phylogenetic analysis identified three diverging phylogroups such as S. enterica Litchfield, S. enterica Enteritidis and S. enterica Kentucky with 11, 8, and 6 strains, respectively. The in vitro antibiogram profiling the Salmonella isolates through disc diffusion method using 13 commercially available antibiotics revealed highest resistance against doxycycline (91.5%) followed by tetracycline and ampicillin (86.0%, in each), and 72.0% isolates as MDR, being resistant to ≥ 5 antibiotics. The MLST typing was carried out based on the PCR amplification of seven housekeeping genes (aroC, hisD, hemD, purE, secA, thrA, and dnaN). MLST typing also revealed three sequence types (STs) such as ST11, ST198, and ST214 in these isolates, and eBURST analysis showed ST11 as the founder genotype. The three STs were highly resistant to tetracyclines and quinolone group of antibiotics, and all of the isolates harboring S. enterica Litchfield showed the highest resistance. Circulating common MLSTs with MDR properties in different farms confirmed the possibility of a common route of intra-farm transmission. We report for the first time of the association serovar Litchfield (ST11) in avian salmonellosis with MDR properties which is an urgent public health concern in Bangladesh.

Role of Mus musculus in the transmission of several pathogens in poultry farms.

This study aimed to analyze the role of Mus musculus as a host of Leptospira spp., lymphocytic choriomeningitis virus (LCMV) and Toxoplasma gondii, in poultry farms of Buenos Aires province, Argentina, and to assess the potential risk of transmission to humans and domestic or breeding animals. Samplings were performed between 2009 and 2011 (S1) and during 2016 (S2). In S1, we studied the prevalence of infection for Leptospira spp. and LCMV, whereas, in S2, we studied the prevalence of infection for Leptospira spp. and T. gondii. In S1, we found an overall Leptospira spp. prevalence in M. musculus of 18% (14/79) and no positive serum samples for LCMV (0/166). In S2, we detected no positive individuals for Leptospira spp. (0/56) and an overall T. gondii seroprevalence of 3.6% (2/56). The probability of Leptospira spp. infection in M. musculus was higher in reproductively active individuals and in samplings subsequent to months with high accumulated precipitation. Our results suggest that, in the poultry farms studied, the presence of M. musculus may be a risk factor in the transmission of Leptospira spp. and T. gondii to humans and domestic animals. The management of farms should include biosecurity measures for farm workers and more effective rodent control.

Outbreak of avian aspergillosis in colonial-bred chicks (Isa Brown) in southern Rio Grande do Sul - case report / [Surto de aspergilose aviária em pintainhas (Isa Brown) de criação colonial na região sul do Rio Grande do Sul - relato de caso]

In this study we describe the epidemiology, clinical signs, and pathology of an outbreak of avian aspergillosis in alternative breeding in the southern region of Rio Grande do Sul, Brazil. Between the fifth and tenth day of life, 360 chicks from a flock of 4000 developed unspecific clinical signs and died. The birds were housed in a reused aviary litter, without previous treatment. In 11 six-day-old female ISA Brown chicks (Gallus gallus domesticus), necropsy revealed firm, yellowish-white, multinodular lesions extending from the pleura to the lung parenchyma. Histologically, a granulomatous, multifocal to coalescent pneumonia was observed. Granulomas were characterized by central necrosis, with heterophil and epithelioid macrophage infiltration and presence of countless Y-shaped intralesional septate hyphae morphologically compatible with Aspergillus spp. The diagnosis through isolation confirmed Aspergillus fumigatus. We highlight the importance of aspergillosis as a primary cause of diseases in the respiratory tract of young birds in alternative breeding. Measures to prevent aspergillosis mainly regarding the reuse of aviary litter are essential in poultry husbandry to prevent economic losses, reduce environmental contamination and mitigate the potential risk to public health.(AU)

Descrevem-se os aspectos epidemiológicos e patológicos de um surto de aspergilose aviária em criação alternativa na região sul do Rio Grande do Sul, Brasil. De um lote de 4000 pintainhas, entre o quinto e o 10º dia de vida, 360 aves apresentaram sinais clínicos inespecíficos e morreram. As aves foram alojadas em cama reutilizada do aviário, sem tratamento prévio. Na necropsia de 11 pintainhas (Gallus gallus domesticus), fêmeas, seis dias de idade da linhagem Isa Brown, foram observadas no pulmão lesões multinodulares, branco-amareladas e firmes, que se estendiam da pleura ao parênquima. Histologicamente foi observada pneumonia granulomatosa, multifocal a coalescente. Os granulomas eram caracterizados por necrose central, com infiltrado inflamatório de heterófilos, macrófagos, células epitelioides com presença de inúmeras hifas septadas intralesionais, semelhantes à letra "Y", morfologicamente compatíveis com Aspergillus spp. O diagnóstico foi confirmado pelo isolamento de Aspergillus fumigatus. Alerta-se para a importância da aspergilose como causa primária de afecções no trato respiratório de aves jovens em criações alternativas. Medidas preventivas relacionadas ao manejo dessas aves são indispensáveis principalmente quanto à reutilização da cama dos aviários, a fim de evitar perdas econômicas, reduzir a contaminação ambiental e o potencial risco à saúde pública.(AU)

Outbreak of avian aspergillosis in colonial-bred chicks (Isa Brown) in southern Rio Grande do Sul - case report / [Surto de aspergilose aviária em pintainhas (Isa Brown) de criação colonial na região sul do Rio Grande do Sul - relato de caso]

In this study we describe the epidemiology, clinical signs, and pathology of an outbreak of avian aspergillosis in alternative breeding in the southern region of Rio Grande do Sul, Brazil. Between the fifth and tenth day of life, 360 chicks from a flock of 4000 developed unspecific clinical signs and died. The birds were housed in a reused aviary litter, without previous treatment. In 11 six-day-old female ISA Brown chicks (Gallus gallus domesticus), necropsy revealed firm, yellowish-white, multinodular lesions extending from the pleura to the lung parenchyma. Histologically, a granulomatous, multifocal to coalescent pneumonia was observed. Granulomas were characterized by central necrosis, with heterophil and epithelioid macrophage infiltration and presence of countless Y-shaped intralesional septate hyphae morphologically compatible with Aspergillus spp. The diagnosis through isolation confirmed Aspergillus fumigatus. We highlight the importance of aspergillosis as a primary cause of diseases in the respiratory tract of young birds in alternative breeding. Measures to prevent aspergillosis mainly regarding the reuse of aviary litter are essential in poultry husbandry to prevent economic losses, reduce environmental contamination and mitigate the potential risk to public health.(AU)

Descrevem-se os aspectos epidemiológicos e patológicos de um surto de aspergilose aviária em criação alternativa na região sul do Rio Grande do Sul, Brasil. De um lote de 4000 pintainhas, entre o quinto e o 10º dia de vida, 360 aves apresentaram sinais clínicos inespecíficos e morreram. As aves foram alojadas em cama reutilizada do aviário, sem tratamento prévio. Na necropsia de 11 pintainhas (Gallus gallus domesticus), fêmeas, seis dias de idade da linhagem Isa Brown, foram observadas no pulmão lesões multinodulares, branco-amareladas e firmes, que se estendiam da pleura ao parênquima. Histologicamente foi observada pneumonia granulomatosa, multifocal a coalescente. Os granulomas eram caracterizados por necrose central, com infiltrado inflamatório de heterófilos, macrófagos, células epitelioides com presença de inúmeras hifas septadas intralesionais, semelhantes à letra "Y", morfologicamente compatíveis com Aspergillus spp. O diagnóstico foi confirmado pelo isolamento de Aspergillus fumigatus. Alerta-se para a importância da aspergilose como causa primária de afecções no trato respiratório de aves jovens em criações alternativas. Medidas preventivas relacionadas ao manejo dessas aves são indispensáveis principalmente quanto à reutilização da cama dos aviários, a fim de evitar perdas econômicas, reduzir a contaminação ambiental e o potencial risco à saúde pública.(AU)

Sources of paratyphoid Salmonella in the production chain of broilers in the Northern mesoregion of Maranhão State, Brazil / Fontes de salmonelas paratíficas na cadeia produtiva de frangos de corte da mesorregião Norte do Estado do Maranhão, Brasil

Paratyphoid Salmonella significantly impacts modern poultry farming, because it is one of the main causes of foodborne diseases in the world. Efforts have been made by the government and poultry industry to reduce the existence of Salmonella in the entire poultry production chain through sanitary programs. The aim of this work was to investigate the occurrence of Salmonella spp. and its serovars in environmental sources of production, poultry, and carcasses slaughtered in an artisanal manner in the northern mesoregion of Maranhão State, Brazil. A total of 520 samples were collected, comprising drag swabs (n = 60), prope (n = 60), cecal feces (n = 60), feed of feeder (n = 60), and cloacal swabs (n = 100) of poultry sent for slaughter, and newly slaughtered carcasses (n = 180). The samples were subjected to culture and isolation of Salmonella spp. and serotyping. The occurrence of the genus Salmonella was 25.0% (15/60) in drag swabs, 16.6% (10/60) in prope, 1.7% (1/60) in cecal feces, absent (0/60) in the feed, 7% (7/100) in cloacal swabs, and 48.9% (88/180) in poultry carcasses. Fifteen Salmonella enterica serovars were identified in the samples, with the highest occurrence in the Schwarzengrund (28.09%; 34/121), Albany (19.83%; 24/121), Enteritidis (7.43%; 9/121), and Heidelberg (7.43%; 9/121). Salmonella ser. Schwarzengrund showed higher predominance in the poultry production chain, with greater isolation in carcass samples (34 isolates), while Salmonella ser. Enteritidis had the highest occurrence in the initial production chain. The results of our study indicate the need to implement sanitary control in farms for paratyphoid salmonella and that artisanal poultry slaughter can increase bacterial dissemination in the final product, representing a public health risk.(AU)

As salmonelas paratíficas causam grande impacto para avicultura moderna, por se tratar de uma das principais causas de doenças de origem alimentar no mundo. Há um esforço de órgãos governamentais e da indústria avícola em diminuir a presença da Salmonella em toda cadeia produtiva de aves, através de programas sanitários. O objetivo desse trabalho foi pesquisar a ocorrência da Salmonella spp. e seus sorovares em fontes ambientais de produção, em aves e em carcaças abatidas de forma artesanal na Mesorregião Norte do Estado do Maranhão, Brasil. Foram coletadas 240 amostras de suabe de arrasto, propé, fezes cecais e ração de comedouros, 100 amostras de suabes de cloaca de aves destinadas ao abate e 180 amostras de carcaças recém abatidas. As amostras foram submetidas a cultura e isolamento de Salmonella spp. e sorotipificação. A ocorrência do gênero Salmonella foi de 25,0% (15/60) em suabe de arrasto, 16,6% (10/60) de propé, 1,7% (1/60) em fezes cecais, ausência (0/60) em ração, 7% (7/100) de suabe cloacal e 48,9% (88/180) em carcaças de frango. Foram identificados 15 sorovares de Salmonella enterica nas amostras, sendo os de maior ocorrência: Schwarzengrund (28,09%; 34/121), Albany (19,83%; 24/121), Enteritidis (7,43%; 9/121) e Heidelberg (7,43%; 9/121). Salmonella ser. Schwarzengrund apresentou maior predominância na cadeia produtiva de aves, com maior isolamento em amostras de carcaça (34 isolados) enquanto Salmonella ser. Enteritidis teve maior ocorrência na cadeia inicial de produção. Os resultados encontrados indicam a necessidade de implementação do controle sanitário nas granjas para as salmonelas paratíficas e que o abate artesanal de aves pode aumentar a disseminação da bactéria no produto final, representando risco para saúde pública.(AU)

Sources of paratyphoid Salmonella in the production chain of broilers in the Northern mesoregion of Maranhão State, Brazil / Fontes de salmonelas paratíficas na cadeia produtiva de frangos de corte da mesorregião Norte do Estado do Maranhão, Brasil

Paratyphoid Salmonella significantly impacts modern poultry farming, because it is one of the main causes of foodborne diseases in the world. Efforts have been made by the government and poultry industry to reduce the existence of Salmonella in the entire poultry production chain through sanitary programs. The aim of this work was to investigate the occurrence of Salmonella spp. and its serovars in environmental sources of production, poultry, and carcasses slaughtered in an artisanal manner in the northern mesoregion of Maranhão State, Brazil. A total of 520 samples were collected, comprising drag swabs (n = 60), prope (n = 60), cecal feces (n = 60), feed of feeder (n = 60), and cloacal swabs (n = 100) of poultry sent for slaughter, and newly slaughtered carcasses (n = 180). The samples were subjected to culture and isolation of Salmonella spp. and serotyping. The occurrence of the genus Salmonella was 25.0% (15/60) in drag swabs, 16.6% (10/60) in prope, 1.7% (1/60) in cecal feces, absent (0/60) in the feed, 7% (7/100) in cloacal swabs, and 48.9% (88/180) in poultry carcasses. Fifteen Salmonella enterica serovars were identified in the samples, with the highest occurrence in the Schwarzengrund (28.09%; 34/121), Albany (19.83%; 24/121), Enteritidis (7.43%; 9/121), and Heidelberg (7.43%; 9/121). Salmonella ser. Schwarzengrund showed higher predominance in the poultry production chain, with greater isolation in carcass samples (34 isolates), while Salmonella ser. Enteritidis had the highest occurrence in the initial production chain. The results of our study indicate the need to implement sanitary control in farms for paratyphoid salmonella and that artisanal poultry slaughter can increase bacterial dissemination in the final product, representing a public health risk.

As salmonelas paratíficas causam grande impacto para avicultura moderna, por se tratar de uma das principais causas de doenças de origem alimentar no mundo. Há um esforço de órgãos governamentais e da indústria avícola em diminuir a presença da Salmonella em toda cadeia produtiva de aves, através de programas sanitários. O objetivo desse trabalho foi pesquisar a ocorrência da Salmonella spp. e seus sorovares em fontes ambientais de produção, em aves e em carcaças abatidas de forma artesanal na Mesorregião Norte do Estado do Maranhão, Brasil. Foram coletadas 240 amostras de suabe de arrasto, propé, fezes cecais e ração de comedouros, 100 amostras de suabes de cloaca de aves destinadas ao abate e 180 amostras de carcaças recém abatidas. As amostras foram submetidas a cultura e isolamento de Salmonella spp. e sorotipificação. A ocorrência do gênero Salmonella foi de 25,0% (15/60) em suabe de arrasto, 16,6% (10/60) de propé, 1,7% (1/60) em fezes cecais, ausência (0/60) em ração, 7% (7/100) de suabe cloacal e 48,9% (88/180) em carcaças de frango. Foram identificados 15 sorovares de Salmonella enterica nas amostras, sendo os de maior ocorrência: Schwarzengrund (28,09%; 34/121), Albany (19,83%; 24/121), Enteritidis (7,43%; 9/121) e Heidelberg (7,43%; 9/121). Salmonella ser. Schwarzengrund apresentou maior predominância na cadeia produtiva de aves, com maior isolamento em amostras de carcaça (34 isolados) enquanto Salmonella ser. Enteritidis teve maior ocorrência na cadeia inicial de produção. Os resultados encontrados indicam a necessidade de implementação do controle sanitário nas granjas para as salmonelas paratíficas e que o abate artesanal de aves pode aumentar a disseminação da bactéria no produto final, representando risco para saúde pública.

Respiratory and other health risks among poultry-farm workers and evaluation of management practices in poultry farms

The current study was conducted on eight poultry farms in Lahore and Sheikhupura to monitor environmental conditions, determine workers health status and assess the implementation of standard management practices. Environmental monitoring, a health questionnaire survey and a respiratory function test were carried out. Seventy-one respondents were selected for the health assessment survey and lung function test. The results showed that the evaluated air-quality parameters, except for temperature and humidity, were well below the permissible occupational limits. Maximum temperature recorded was 32.75 ºC, while the highest humidity level was 85.5%. Farms were shown to be compliant with standard guidelines and management practices. The workers health survey indicated lower prevalence of work-related symptoms as compared to previous studies. However, most workers were not subjected to overall physical hazards, 21.1% of workers suffered from heat-induced dermatosis, and 38% suffered from heat exhaustion. Eye problems (watery, redness and itchiness) were experienced by 16.9% to 31%. Reported respiratory symptoms included wheezing during colds (18.3%), wheezing other than during colds (1.4%), chest tightness (16.9%), shortness of breath along with chest tightness (9.9%), regular breathing difficulties (14.1%), and coughing (15.5%). Observed lung function pattern, as measured by FEV1/FVC ratio, was 87 ± 17.7, with 65% workers having ‘restrictive disorder and 21% normal lung function pattern, while 21% presented ‘obstructive lung function. The study concludes an overall better health and safety management in the selected poultry farms.(AU)

Respiratory and other health risks among poultry-farm workers and evaluation of management practices in poultry farms

The current study was conducted on eight poultry farms in Lahore and Sheikhupura to monitor environmental conditions, determine workers’ health status and assess the implementation of standard management practices. Environmental monitoring, a health questionnaire survey and a respiratory function test were carried out. Seventy-one respondents were selected for the health assessment survey and lung function test. The results showed that the evaluated air-quality parameters, except for temperature and humidity, were well below the permissible occupational limits. Maximum temperature recorded was 32.75 ºC, while the highest humidity level was 85.5%. Farms were shown to be compliant with standard guidelines and management practices. The workers’ health survey indicated lower prevalence of work-related symptoms as compared to previous studies. However, most workers were not subjected to overall physical hazards, 21.1% of workers suffered from heat-induced dermatosis, and 38% suffered from heat exhaustion. Eye problems (watery, redness and itchiness) were experienced by 16.9% to 31%. Reported respiratory symptoms included wheezing during colds (18.3%), wheezing other than during colds (1.4%), chest tightness (16.9%), shortness of breath along with chest tightness (9.9%), regular breathing difficulties (14.1%), and coughing (15.5%). Observed lung function pattern, as measured by FEV1/FVC ratio, was 87 ± 17.7, with 65% workers having ‘restrictive’ disorder and 21% normal lung function pattern, while 21% presented ‘obstructive’ lung function. The study concludes an overall better health and safety management in the selected poultry farms.

Consumption Pattern of Bromadiolone in Presence of Alternative Food by House Mice (Mus musculus) Infesting Poultry Farms

Poultry farms in Central Argentina are often infested by Mus musculus L., despite the regular application of the rodenticide bromadiolone. This failure may be explained by the consumption pattern of mice, which may prefer alternative foods available on the farms to bromadiolone baits. Here we examine the consumption pattern of bromadiolone in the presence of wheat by M. musculus infesting poultry farms compared with the laboratory CF1 mouse strain. Overall, the poultry farm mice had longer survival and lower total food consumption in comparison with the CF1 mice. On the first day of the experiment, rodents from both strains and sexes consumed bromadiolone in the same proportion as wheat. On the second day, female mice of both origins showed a significant decrease in the consumption of bromadiolone, while males kept that proportion constant. Despite the consumption differences between males and females, survival rates were not different. We concluded that rodents from farms behaved as if they had never been in contact with bromadiolone, since they showed the same pattern of poison consumption that the CF1 mice. Females may have associated physical upset with the consumption of bromadiolone, since they decreased its consumption relative to wheat. However, this consumption pattern did not help them to achieve higher survival than males. On poultry farms, the balanced food fed to chickens may function as an alternative food to the poison for rodents. Therefore, we propose that rodenticide should be applied during downtime, when shed are cleaned and there is no chicken feed, which could be used as alternative food.(AU)

Consumption Pattern of Bromadiolone in Presence of Alternative Food by House Mice (Mus musculus) Infesting Poultry Farms

Poultry farms in Central Argentina are often infested by Mus musculus L., despite the regular application of the rodenticide bromadiolone. This failure may be explained by the consumption pattern of mice, which may prefer alternative foods available on the farms to bromadiolone baits. Here we examine the consumption pattern of bromadiolone in the presence of wheat by M. musculus infesting poultry farms compared with the laboratory CF1 mouse strain. Overall, the poultry farm mice had longer survival and lower total food consumption in comparison with the CF1 mice. On the first day of the experiment, rodents from both strains and sexes consumed bromadiolone in the same proportion as wheat. On the second day, female mice of both origins showed a significant decrease in the consumption of bromadiolone, while males kept that proportion constant. Despite the consumption differences between males and females, survival rates were not different. We concluded that rodents from farms behaved as if they had never been in contact with bromadiolone, since they showed the same pattern of poison consumption that the CF1 mice. Females may have associated physical upset with the consumption of bromadiolone, since they decreased its consumption relative to wheat. However, this consumption pattern did not help them to achieve higher survival than males. On poultry farms, the balanced food fed to chickens may function as an alternative food to the poison for rodents. Therefore, we propose that rodenticide should be applied during downtime, when shed are cleaned and there is no chicken feed, which could be used as alternative food.

Surveillance for Newcastle disease virus, Avian influenza virus and Mycoplasma gallisepticum in wild birds near commercial poultry farms surrounded by Atlantic rainforest remnants, Southeastern Brazil

The geographic overlap between areas of Atlantic rainforest and human activities allows interactions to occur between humans and wild and domestic animals. Despite the great importance of the domestic animal-wildlife-human interface that occurs at poultry farms in terms of public health, economic production and wildlife conservation, there are few studies in Brazil examining the distribution and health of wild birds that interact with poultry farms. From January to December 2010, mist nets were used to capture 166 free-ranging birds that were within close proximity to three poultry farms in Atlantic rainforest remnants in south-eastern Brazil. The species composition was examined, and molecular methods were used to test for avian influenza virus, Newcastle disease virus, and Mycoplasma gallisepticum. The avian communities near the poultry farms were dominated by three synanthropic species, which corresponded to 70% of all captured individuals: house sparrows Passer domesticus (33%), saffron finches (Sicalis flaveola) (22%), and ruddy ground-doves (Columbina talpacoti) (15%). These predominant bird species were in poor body condition (27%), were infested with feather mites (43%), or presented both conditions (23%). No evidence of infection by avian influenza virus, Newcastle disease virus or M. gallisepticum was identified in any of the studied birds. Although no evidence of the studied pathogens was, our findings demonstrate that differences in the environmental characteristics and biosecurity practices influence the wild bird community near poultry farms, which in turn may affect the health status of these synanthropic birds and strengthen their role in the transmission of pathogens.(AU)

Surveillance for Newcastle disease virus, Avian influenza virus and Mycoplasma gallisepticum in wild birds near commercial poultry farms surrounded by Atlantic rainforest remnants, Southeastern Brazil

The geographic overlap between areas of Atlantic rainforest and human activities allows interactions to occur between humans and wild and domestic animals. Despite the great importance of the domestic animal-wildlife-human interface that occurs at poultry farms in terms of public health, economic production and wildlife conservation, there are few studies in Brazil examining the distribution and health of wild birds that interact with poultry farms. From January to December 2010, mist nets were used to capture 166 free-ranging birds that were within close proximity to three poultry farms in Atlantic rainforest remnants in south-eastern Brazil. The species composition was examined, and molecular methods were used to test for avian influenza virus, Newcastle disease virus, and Mycoplasma gallisepticum. The avian communities near the poultry farms were dominated by three synanthropic species, which corresponded to 70% of all captured individuals: house sparrows Passer domesticus (33%), saffron finches (Sicalis flaveola) (22%), and ruddy ground-doves (Columbina talpacoti) (15%). These predominant bird species were in poor body condition (27%), were infested with feather mites (43%), or presented both conditions (23%). No evidence of infection by avian influenza virus, Newcastle disease virus or M. gallisepticum was identified in any of the studied birds. Although no evidence of the studied pathogens was, our findings demonstrate that differences in the environmental characteristics and biosecurity practices influence the wild bird community near poultry farms, which in turn may affect the health status of these synanthropic birds and strengthen their role in the transmission of pathogens.

Using nonparametric analysis (DEA) for measuring technical efficiency in poultry farms

The objective of this study was to determine the economic efficiency of resource utilization in broiler production farms using a non-parametric production function, data envelopment analysis (DEA). Data for the analysis were collected from a cross section of 44 farmers using a multi-stage sampling procedure. In DEA models the farmers that produce their level of output with the least amount of input serve as benchmarks against which the input use inefficiency of all other farmers can be measured. The total variable costs, net return and benefit cost ratio were calculated to be 3506.29 $ (1000 bird)-1, 1386.53 $ (1000 bird) -1 and 1.38, respectively. The average values of technical and scale efficiencies of farmers were found to be 0.92 and 0.93. The results also revealed that about 10% of the total input resources could be saved if the farmers follow the input package recommended by the DEA.

Using nonparametric analysis (DEA) for measuring technical efficiency in poultry farms

The objective of this study was to determine the economic efficiency of resource utilization in broiler production farms using a non-parametric production function, data envelopment analysis (DEA). Data for the analysis were collected from a cross section of 44 farmers using a multi-stage sampling procedure. In DEA models the farmers that produce their level of output with the least amount of input serve as benchmarks against which the input use inefficiency of all other farmers can be measured. The total variable costs, net return and benefit cost ratio were calculated to be 3506.29 $ (1000 bird)-1, 1386.53 $ (1000 bird) -1 and 1.38, respectively. The average values of technical and scale efficiencies of farmers were found to be 0.92 and 0.93. The results also revealed that about 10% of the total input resources could be saved if the farmers follow the input package recommended by the DEA.

Assessment of the risks of rats (Rattus norvegicus) and opossums (Didelphis albiventris) in different poultry-rearing areas in Argentina

We have studied the prevalence of Trichinella spiralis, Leptospira spp. and Salmonella spp. in rats and opossums that inhabit poultry farms of Exaltación de la Cruz, Buenos Aires, Argentina, to determine the potential sanitary risk for humans that are in contact with these animals. The study was carried out on 48 poultry farms between spring 1999 and winter 2001. The study of opossums began in winter 2000. During the study period we captured 152 Rattus norvegicus, 3 Rattus rattus, 16 Didelphis albiventris and 1 Lutreolina crassicaudata. We have registered the presence of rats and opossums in 70% and 27% of the studied farms, respectively. The percentage of farms with rats was independent of the presence or absence of pigs. We did not detect the presence of Leptospira spp. and Trichinella spiralis in any individual. We detected the presence of Salmonella Enteritidis in one Rattus norvegicus and one Didelphis albiventris. According to our results, the rats and opossums of poultry farms may not report a risk factor in the transmission of Trichinella and Leptospira under the present conditions; but the detection of Salmonella Enteritidis in rats as well as in opossums suggests the idea of applying prophylactics measurements on poultry farms.

A prevalência de Trichinella spiralis, Leptospira spp. e Salmonella spp. foi estudada em ratos e gambás que habitam granjas avícolas da região de Exaltación de la Cruz, Buenos Aires, Argentina, com o objetivo de determinar o potencial risco sanitário para pessoas que ficam em contato com esses animais. O estudo foi realizado entre a primavera de 1999 e o inverno de 2001 em 48 granjas avícolas. O estudo em gambás iniciou-se no inverno de 2000. Foram capturados 152 Rattus norvegicus, 3 Rattus rattus, 16 Didelphis albiventris e 1 Lutreolina crassicaudata. Registrou-se a presença de ratos e de gambás em 70% e 27% das granjas estudadas, respectivamente. A percentagem de granjas com ratos foi independente da presença ou da ausência de suínos. Não foi detectada a presença de Leptospira spp. e de Trichinella spiralis em nenhum animal avaliado. Foi detectada, porém, a presença de Salmonella Enteritidis em um Rattus norvegicus e em um Didelphis albiventris. Nas condições em que esse estudo foi realizado, os nossos resultados indicam que ratos e gambás que habitam granjas avícolas não constituem um fator de risco na transmissão de Trichinella e de Leptospira. A detecção de Salmonella Enteritidis tanto em ratos quanto em gambás, porém, sugere a necessidade de aplicar medidas profiláticas em granjas avícolas para maior controle desse agente.