Detección serológica de Brucella suis, virus de influenza y virus de la enfermedad de Aujeszky en criaderos porcinos familiares de menos de 100 madres en Argentina / Serological detection of Brucella suis, influenza virus and Aujeszky's disease virus in backyard and small swine holders in Argentina

Los criaderos porcinos de menos de 100 madres representan más del 99% de los de todo el país; sin embargo, existen escasos reportes sobre su situación sanitaria y productiva. Se recabó información productiva y se tomaron muestras para detectar anticuerpos contra Brucella suis (Bs), virus de la enfermedad de Aujeszky (VA) y virus de influenza (VI) en 68 establecimientos de menos de 100 madres ubicados en la región norte, centro y sur del país. El 80% de los establecimientos fueron positivos al VI H1 pandémico 2009, el 11% al H3 clúster 2, mientras que el 11,7% presentó anticuerpos contra el VA y el 6% contra Bs. Ninguno de los productores conocía los factores de riesgo para la transmisión de enfermedades del cerdo al humano. El 47% compra sus reproductores a pares o en ferias. En lo que respecta a normas de bioseguridad, solo el 16% de los establecimientos tenía cerco perimetral y el 37% de las granjas contaba con asesoramiento veterinario. Los resultados de este estudio demuestran que la caracterización productiva y el relevamiento sanitario son de suma importancia para mejorar la productividad y reducir el riesgo de transmisión de enfermedades. El conocimiento de la situación sanitaria y de los factores de riesgo es necesario para conseguir un mejor control y la erradicación de enfermedades en sistemas de baja tecnificación. Se deberían llevar a cabo estudios más representativos a nivel país para detectar los agentes circulantes y, sobre la base de esta información, implementar medidas de prevención y control.

Farmers raising less than 100 sows represent more than 99% of swine producers in Argentina, although little is known about their sanitary status and productive characteristics in the country. Sanitary and productive information was obtained. Furthermore, samples for serological studies were taken to detect antibodies against Brucella suis (Bs), Aujeszky's disease virus (AV) and influenza virus (IV) in 68 backyard and small producers with less than 100 sows located in the north, central and south regions of Argentina. Antibodies against H1 pandemic were detected in 80% of the farms while 11%, 11.7% and 6.0% of the producers were positive to influenza H3 cluster 2, AV and Bs, respectively. None of the producers was aware of the risk factors concerning the transmission of diseases from pigs to humans. A percentage of 47% of them buy pigs for breeding from other farmers and markets. With regard to biosecurity measures, only 16% of the farms had perimeter fences. The results of this study demonstrate that productive characterization and disease surveys are important to improve productivity and to reduce the risk of disease transmission among animals and humans. The study of sanitary status and risk factors is necessary for better control and eradication of diseases in backyard or small producers. More representative studies at country level should be carried out to detect the pathogensthat circulate and, with this knowledge, to implement prevention and control measures.

[Serological detection of Brucella suis, influenza virus and Aujeszky's disease virus in backyard and small swine holders in Argentina]. / Detección serológica de Brucella suis, virus de influenza y virus de la enfermedad de Aujeszky en criaderos porcinos familiares de menos de 100 madres en Argentina.

Farmers raising less than 100 sows represent more than 99% of swine producers in Argentina, although little is known about their sanitary status and productive characteristics in the country. Sanitary and productive information was obtained. Furthermore, samples for serological studies were taken to detect antibodies against Brucella suis (Bs), Aujeszky's disease virus (AV) and influenza virus (IV) in 68 backyard and small producers with less than 100 sows located in the north, central and south regions of Argentina. Antibodies against H1 pandemic were detected in 80% of the farms while 11%, 11.7% and 6.0% of the producers were positive to influenza H3 cluster 2, AV and Bs, respectively. None of the producers was aware of the risk factors concerning the transmission of diseases from pigs to humans. A percentage of 47% of them buy pigs for breeding from other farmers and markets. With regard to biosecurity measures, only 16% of the farms had perimeter fences. The results of this study demonstrate that productive characterization and disease surveys are important to improve productivity and to reduce the risk of disease transmission among animals and humans. The study of sanitary status and risk factors is necessary for better control and eradication of diseases in backyard or small producers. More representative studies at country level should be carried out to detect the pathogensthat circulate and, with this knowledge, to implement prevention and control measures.

Brucella suis bacteremia misidentified as Ochrobactrum anthropi by the VITEK 2 system.

Ochrobactrum and Brucella are genetically related genera of the family Brucellaceae, sharing 98.8% rRNA similarity. Because of their phenotypic similarity, Ochrobactrum can be miscoded as Brucella by automated identification systems. The misidentification on blood cultures (BCs) of B. suis as O. anthropi by the VITEK 2 system is herein described. A 67-year-old male with a prosthetic mitral valve and fever was admitted with bacteremia due to a Gram-negative coccobacillus identified as O. anthropi by VITEK 2. The patient's fever persisted along with positive blood cultures despite specific antimicrobial treatment. Due to this adverse outcome, the patient was interrogated again and admitted having domestic swine. Serological tests were positive for acute brucellosis. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) of BC strains identified B. suis biovar 1. Timely identification of Brucella is essential for providing proper treatment to the patient and for advising safe handling of laboratory cultures in biological safety cabinets to prevent laboratory-acquired infection. Countries where brucellosis is endemic must be aware of this possibility.

Prevalência e fatores de risco para brucelose suína em Mossoró-RN / Prevalence and risk factors for brucellosis in pigs in Mossoró-RN

A presente pesquisa teve como objetivo determinar a prevalência da brucelose e seus fatores de risco no rebanho suíno de Mossoró/RN. Compreendeu um estudo epidemiológico transversal e de abordagem quantitativa, no qual foram coletadas 412 amostras sanguíneas de suínos provenientes dos principais produtores do município e realizada inspeção das criações com entrevistas aos produtores. Anticorpos anti-Brucella spp. foram detectados pelo teste do antígeno acidificado tamponado (AAT) e confirmados pela reação de fixação de complemento (RFC). A prevalência da brucelose nos suínos foi de 27,0 por cento no teste de AAT e 17,5 por cento na RFC. Em 55 por cento das propriedades pesquisadas havia pelo menos um animal positivo, e a prevalência nestas variou de 6,7 por cento a 80,0 por cento. Os fatores de risco que estavam influenciando a ocorrência da doença foram: a presença de ratos nas criações, o contato com bovinos e a faixa etária jovem dos animais. Os resultados do estudo permitiram concluir que o agente etiológico da brucelose estava circulando em suínos do município de Mossoró-RN, com elevada prevalência no rebanho e nas propriedades, evidenciando o risco de transmissão desta zoonose para o homem.(AU)

The study aimed to determine the prevalence of brucellosis and its risk factors in the pig herd of Mossoró-RN. Comprised a cross-sectional quantitative approach and epidemiological study, where 412 blood samples of pigs from major producers in the municipality were collected and inspection of herds with interviews with producers were conducted. Antibodies to Brucella spp. were detected by the rose Bengal test (RBT) and confirmed by the complement fixation test (CFT). The prevalence of brucellosis in pigs was 27.0 percent in the RBT and 17.5 percent in the CFT. In 55 percent of the surveyed properties there was at least one positive animal, and these prevalence ranged from 6.7 percent to 80.0 percent. Risk factors that were influencing the occurrence of the disease were the presence of rats in the farms, contact with cattle and the young age of the animals. The study results showed that the causative agent of brucellosis was circulating in pigs in the municipality of Mossoró-RN, with high prevalence in the herd and on the properties, indicating the risk of transmission of this zoonosis to humans.(AU)

Prevalência e fatores de risco para brucelose suína em Mossoró-RN / Prevalence and risk factors for brucellosis in pigs in Mossoró-RN

A presente pesquisa teve como objetivo determinar a prevalência da brucelose e seus fatores de risco no rebanho suíno de Mossoró/RN. Compreendeu um estudo epidemiológico transversal e de abordagem quantitativa, no qual foram coletadas 412 amostras sanguíneas de suínos provenientes dos principais produtores do município e realizada inspeção das criações com entrevistas aos produtores. Anticorpos anti-Brucella spp. foram detectados pelo teste do antígeno acidificado tamponado (AAT) e confirmados pela reação de fixação de complemento (RFC). A prevalência da brucelose nos suínos foi de 27,0 por cento no teste de AAT e 17,5 por cento na RFC. Em 55 por cento das propriedades pesquisadas havia pelo menos um animal positivo, e a prevalência nestas variou de 6,7 por cento a 80,0 por cento. Os fatores de risco que estavam influenciando a ocorrência da doença foram: a presença de ratos nas criações, o contato com bovinos e a faixa etária jovem dos animais. Os resultados do estudo permitiram concluir que o agente etiológico da brucelose estava circulando em suínos do município de Mossoró-RN, com elevada prevalência no rebanho e nas propriedades, evidenciando o risco de transmissão desta zoonose para o homem.

The study aimed to determine the prevalence of brucellosis and its risk factors in the pig herd of Mossoró-RN. Comprised a cross-sectional quantitative approach and epidemiological study, where 412 blood samples of pigs from major producers in the municipality were collected and inspection of herds with interviews with producers were conducted. Antibodies to Brucella spp. were detected by the rose Bengal test (RBT) and confirmed by the complement fixation test (CFT). The prevalence of brucellosis in pigs was 27.0 percent in the RBT and 17.5 percent in the CFT. In 55 percent of the surveyed properties there was at least one positive animal, and these prevalence ranged from 6.7 percent to 80.0 percent. Risk factors that were influencing the occurrence of the disease were the presence of rats in the farms, contact with cattle and the young age of the animals. The study results showed that the causative agent of brucellosis was circulating in pigs in the municipality of Mossoró-RN, with high prevalence in the herd and on the properties, indicating the risk of transmission of this zoonosis to humans.

Brucella suis in armadillos (Chaetophractus villosus) from La Pampa, Argentina.

Brucellosis is a zoonotic disease transmitted from an animal reservoir to humans. Both, wildlife and domestic animals, contribute to the spreading of these zoonosis. The surveillance of the animal health status is strictly regulated for domestic animals, whereas disease monitoring in wildlife does not exist. The aim of the present study was to provide data on the prevalence of anti-Brucella antibodies in Chaetophractus villosus from a region of La Pampa, Argentina to assess public health risks. The C. villosus is endemic to South America, and in Argentina it represents a food resource for human consumption. A total of 150 sera of armadillos bleeding between 2007 and 2010 were tested using buffered plate antigen test (BPAT), serum agglutination test (SAT), 2-mercaptoethanol (2-ME) and complement fixation test (CFT), for the detection of anti-Brucella antibodies. Antibodies to Brucella sp. were found in 16% (24:150) of the armadillos tested using the BPAT test. All 24 positive samples were confirmed by the SAT, 2-ME and CFT tests. Strain isolation was attempted from liver and spleen samples of two animals with positive serology. Isolates were characterized by conventional biotyping and identification of specific DNA using polymerase chain reaction (PCR). A total of 2 isolates were recovered from spleen and liver. Both of them were identified as Brucella suis biovar 1. This preliminary study provides the first report on the seroprevalence of brucellosis and describes the first isolate of B. suis biovar 1 in C. villosus in Argentina.

Human brucellosis at a pig slaughterhouse.

Seventeen workers in a pig slaughterhouse with signs and symptoms compatible with brucellosis were clinically examined at the outpatient service of different health institutions and studied by serological tests during the period 2005-2011. Eleven blood cultures were taken and six Brucella suis strains were isolated, three biovar 1 and three with atypical characteristics. In order to confirm that these cases had no common source, a variable number of tandem repeat (VNTR) analyses were performed on 5 of the 6 strains whose results showed substantial heterogeneity in the genotypes, thereby demonstrating that the immediate origin was not the same. Two hundred adult pigs admitted for slaughter at the plant were sampled by convenience and tested by buffered antigen plate test (BPAT), serum agglutination test (SAT) and 2-mercapto-ethanol test (MET). Seven of 62 males (11%) and 25/138 (18%) females tested positive. The study results contribute information on risk scenarios for packing plant workers and underscore the need to improve plant workers' education on appropriate containment measures and to actively screen animals for swine brucellosis.

Soropositividade para brucelose em suínos em abatedouros / Seropositivity for brucellosis in pigs in slaughter houses

O presente trabalho teve por objetivo investigar a soropositividade para brucelose em suínos em abatedouros. Foram coletados 910 soros de suínos, procedentes de 30 propriedades, abatidos em frigoríficos da região central do estado de São Paulo, e submetidos às provas de soroaglutinaçao com antígeno tamponado acidificado (AAT) e 2-Mercaptoetanol (2-Me) objetivando determinar a ocorrência da enfermidade nesta espécie. Do total de soros avaliados foram observados 25 (2,7%) animais reagentes ao AAT pertencentes a 10 propriedades, caracterizando 36% de propriedades positivas. Dos animais positivos ao AAT, 16% apresentaram titulo de 25 (incompleto) e 52% titulo de 25 na soroaglutinação lenta (SAL), 8% apresentaram titulo de 50 incompleto na SAL e 25 incompleto no 2-ME e 8% apresentaram titulo de 50 na SAL e 25 no 2-ME. Estes resultados demonstram o elevado percentual de propriedades positivas para brucelose nesta região e ressaltam a necessidade de implementação de programas oficiais efetivos para o controle da brucelose suína.(AU)

The aim of this investigation was to evaluate the seropositivity for brucellosis in pig slaughterhouses. Sera of 910 pigs from 30 farms and slaughtered at slaughterhouses, located in the central region of the state of São Paulo, were tested with Buffered Plate Acidified Antigen (BPAA) and 2-mercaptoethanol (2-Me) as confirmatory test to determine the serological positivity in this species. The results demonstrated that 25 (2.7%) of the pigs from 10 farms reacted to BPAA, corresponding to 36% of positive properties. From BPAA positive animals 16% and 52% presented titers of 25 incomplete and 25 respectively in the Tube agglutination test (TAT), 8% presented 50 and 25 incomplete, respectively, in TAT and 2-ME, and 8% resulted 50 and 25 positive in TAT and 2-ME, respectively. These results demonstrate the high percentage of positive farms for swine brucellosis in this region and reinforce the need for official and effective program implementation for the swine brucellosis control.(AU)

Soropositividade para brucelose em suínos em abatedouros / Seropositivity for brucellosis in pigs in slaughter houses

O presente trabalho teve por objetivo investigar a soropositividade para brucelose em suínos em abatedouros. Foram coletados 910 soros de suínos, procedentes de 30 propriedades, abatidos em frigoríficos da região central do estado de São Paulo, e submetidos às provas de soroaglutinaçao com antígeno tamponado acidificado (AAT) e 2-Mercaptoetanol (2-Me) objetivando determinar a ocorrência da enfermidade nesta espécie. Do total de soros avaliados foram observados 25 (2,7%) animais reagentes ao AAT pertencentes a 10 propriedades, caracterizando 36% de propriedades positivas. Dos animais positivos ao AAT, 16% apresentaram titulo de 25 (incompleto) e 52% titulo de 25 na soroaglutinação lenta (SAL), 8% apresentaram titulo de 50 incompleto na SAL e 25 incompleto no 2-ME e 8% apresentaram titulo de 50 na SAL e 25 no 2-ME. Estes resultados demonstram o elevado percentual de propriedades positivas para brucelose nesta região e ressaltam a necessidade de implementação de programas oficiais efetivos para o controle da brucelose suína.

The aim of this investigation was to evaluate the seropositivity for brucellosis in pig slaughterhouses. Sera of 910 pigs from 30 farms and slaughtered at slaughterhouses, located in the central region of the state of São Paulo, were tested with Buffered Plate Acidified Antigen (BPAA) and 2-mercaptoethanol (2-Me) as confirmatory test to determine the serological positivity in this species. The results demonstrated that 25 (2.7%) of the pigs from 10 farms reacted to BPAA, corresponding to 36% of positive properties. From BPAA positive animals 16% and 52% presented titers of 25 incomplete and 25 respectively in the Tube agglutination test (TAT), 8% presented 50 and 25 incomplete, respectively, in TAT and 2-ME, and 8% resulted 50 and 25 positive in TAT and 2-ME, respectively. These results demonstrate the high percentage of positive farms for swine brucellosis in this region and reinforce the need for official and effective program implementation for the swine brucellosis control.

Brucella suis Biovar 1 isolated from a hepatic abscess drainage.

Positive cultures from hepatic abscess drainage are extremely rare, and in this case the infection would have remained undiagnosed if Brucella suis had not been isolated. Failure to correctly diagnose this zoonosis delays patient treatment and is dangerous, as in this case that could have been a laboratory-acquired disease. This type of infection is preventable if proper safety protocols are established and followed.

Brucellosis due to Brucella suis in a swine herd associated with a human clinical case in the State of São Paulo, Brazil.

Brucella suis has been recognized as the major etiological agent of human brucellosis in areas free from Brucella melitensis infection. However, with changes in swine management, the occurrence of swine brucellosis has decreased as has the human incidence of B. suis infection. A swine brucellosis outbreak within a herd from Jaboticabal (São Paulo, Brazil) was detected in July 2006. The herd comprised approximately 300 sows and 1,500 finishing animals. Many sows within this herd experienced abortions, while others exhibited vaginal discharge; three sows suffered posterior paralysis. Among 271 sows, 254 (93.7%) tested positive for brucellosis by complement fixation, and among 62 randomly bled finishing animals, 17 (27.4%) also tested positive. The B. suis biovar 1 was cultured from 14 aborted fetuses and six sows. Brucella was identified using routine methods. Fourteen farm workers were tested using agglutination tests, with three workers showing evidence of Brucella antibody titers. A 39-year-old woman, who worked with maternal pigs and had direct contact with aborted fetuses, presented an agglutinating titer of 480 IU/mL and displayed clinical signs of infection. Our findings suggest that despite a reduction of swine brucellosis throughout Brazil, B. suis infection still occurs, thereby posing a zoonotic risk.