Neospora caninum infection in cattle in the state of Amazonas, Brazil: seroprevalence, spatial distribution and risk factors.

Livestock in the Amazon has grown significantly and, although neosporosis in cattle has been reported worldwide, there is no information about N. caninum in production systems in the state of Amazonas. The objective of this study was to determine the prevalence of anti-Neospora caninum antibodies in cattle, their spatial distribution and the risk factors associated with N. caninum infection in the state of Amazonas. Questionnaires were applied to farmers to assess risk factors associated with N. caninum infection. Blood samples were collected from 1,073 animals on 47 farms in 33 municipalities in the four Amazonian subpopulations. IgG anti-N.caninum antibodies were detected by the indirect fluorescence test, with a general prevalence of 30.2%, being seropositive in 43 farms (91.5%), with prevalence ranging from 2.2% to 69.2%. The highest number of high density points was found in subpopulation 3 (municipality of Apuí and other municipalities on the Madeira River and affluent). It was concluded that N. caninum is present with high seroprevalence values, when compared to other cattle producing states in the Amazon region of Brazil. The identified factors can be used as risk indicators so that control measures can be implemented to prevent infection by N. caninum in these herds.

Neospora caninum infection in cattle in the state of Amazonas, Brazil: seroprevalence, spatial distribution and risk factors / Infecção por Neospora caninum em bovinos no estado do Amazonas, Brasil: soroprevalência, distribuição espacial e fatores de risco

Abstract Livestock in the Amazon has grown significantly and, although neosporosis in cattle has been reported worldwide, there is no information about N. caninum in production systems in the state of Amazonas. The objective of this study was to determine the prevalence of anti-Neospora caninum antibodies in cattle, their spatial distribution and the risk factors associated with N. caninum infection in the state of Amazonas. Questionnaires were applied to farmers to assess risk factors associated with N. caninum infection. Blood samples were collected from 1,073 animals on 47 farms in 33 municipalities in the four Amazonian subpopulations. IgG anti-N.caninum antibodies were detected by the indirect fluorescence test, with a general prevalence of 30.2%, being seropositive in 43 farms (91.5%), with prevalence ranging from 2.2% to 69.2%. The highest number of high density points was found in subpopulation 3 (municipality of Apuí and other municipalities on the Madeira River and affluent). It was concluded that N. caninum is present with high seroprevalence values, when compared to other cattle producing states in the Amazon region of Brazil. The identified factors can be used as risk indicators so that control measures can be implemented to prevent infection by N. caninum in these herds.

Resumo A pecuária na Amazônia tem crescido significativamente e, embora a neosporose em bovinos tenha sido relatada em todo o mundo, não há informações sobre N. caninum nos sistemas de produção no estado do Amazonas. Objetivou-se determinar a prevalência de anticorpos anti-Neospora caninum em bovinos, sua distribuição espacial e os fatores de risco associados à infecção por N. caninum no estado do Amazonas. Questionários foram aplicados aos fazendeiros, para avaliar fatores de risco associados à infecção por N. caninum. Amostras de sangue foram coletadas de 1.073 animais em 47 fazendas, em 33 municípios das quatro subpopulações amazonenses. Anticorpos IgG anti-N.caninum foram detectados pelo teste de imunofluorescência indireta, com prevalência geral de 30,2%, com soropositividade em 43 fazendas (91,5%), com prevalência variando de 2,2% a 69,2%. O maior número de pontos de alta densidade foi encontrado na subpopulação 3 (município de Apuí e demais municípios do rio Madeira e afluentes). Concluiu-se que N. caninum está presente com altos valores de soroprevalência, quando comparado a outros estados produtores de gado na região amazônica do Brasil. Os fatores identificados podem ser usados como indicadores de risco, para que medidas de controle possam ser implementadas para prevenir a infecção por N. caninum nesses rebanhos.

Serological survey and risk factors for Toxoplasma gondii infection in cattle from Amazonas, Brazil.

Beef cattle farming in the Amazon region has expanded rapidly, but information on herd health is still scanty. The purpose of this study was to determine the presence of anti-Toxoplasma gondii antibodies in cattle, its spatial distribution and the risk factors associated with the infection in the state of Amazonas, Brazil. Blood samples were collected from 1073 animals on 47 farms, located in 33 municipalities in the four state subpopulations. Anti-T. gondii IgG antibodies were detected by means of the indirect fluorescent antibody test (IFAT). The overall prevalence was 30.9 % (332/1073), and seropositive animals were identified at 93.6 % farms (44/47). All the subpopulations studied in the state of Amazonas had cattle herds seropositive for T. gondii, with some areas showing higher prevalence rates. The risk factors identified in the logistic regression were number of animals (OR = 4.43) and presence of domestic cats (OR = 1.98). It is advisable to correct identified risk factors, particularly insofar as the definitive hosts of T. gondii are concerned. Attention should also focus on beef consumption, given the prevalence of T. gondii infection among cattle and the widespread clandestine slaughtering that occurs in this state.

Toxoplasma gondii in backyard pigs: seroepidemiology and mouse bioassay.

The aim of this study was to evaluate the occurrence of Toxoplasma gondii in backyard pigs destined for human consumption in Pernambuco state, Brazil. Blood and tissue samples (liver, heart, brain, lung and diaphragm) were collected from 224 pigs from legal slaughterhouses and tested for T. gondii infection. Antibodies to T. gondii were found in the sera of 37.9% (85/224) by using the immunofluorescence antibody test (cut-off - 1:64). Tissue samples from seropositive pigs were bioassayed in mice. Tissue samples from seropositive pigs and from mice of the bioassay were submitted to histopathology, immunohistochemistry, polymerase chain reaction (PCR) and sequencing; 14.1% of pig tissue samples and 27.7% of bioassayed mouse samples were positive for T. gondii DNA, but all pig and mouse tissues were negative in histopathology analysis and immunochemistry. By using a risk assessment questionnaire, there was significant difference (p<0.001) in seroprevalence of 21.2% (reproducer) and 3.1% (finishing pig). These data serve as indicative of the sanitary conditions and risk of T. gondii infection for backyard pigs. Preventive measures must be implemented by health services to avoid toxoplasmosis human cases due to ingestion of pig meat.

First report of genotype #65 of Toxoplasma gondii in pigs.

The aim of the present study was to isolate and genotype Toxoplasma gondii from pigs slaughtered for human consumption in northeastern Brazil. Indirect immunofluorescence antibody test (IFAT) was used to screen positive pigs. Tissues samples of animals with antibody titers ≥64 were submitted to bioassay in mice. One isolate of T. gondii was obtained, and the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, using 11 markers (SAG1, SAG2, altSAG2, SAG3, BTUB, GRA6, c228, c292, L358, PK1, and APICO), was applied to evaluate the genetic variability. DNA from reference strains was used as a positive control. By means of genetic analysis, genotype ToxoDB #65 was identified, which is considered an atypical strain. This is the first record of genotype #65 in pigs. Thus, further studies in this region are necessary to determine the genetic variability of T. gondii in pigs and possible impact on public health.