Herd and animal level prevalences and risk factors for Neospora caninum infection in cattle in the state of Paraíba, northeastern Brazil.

Bovine neosporosis is a globally important disease, causing abortions and significant economic losses. In Brazil, studies on neosporosis in cattle are few and based on limited samples and/or from limited areas. We aimed to determine the herd and animal levels seroprevalence and associated factors for Neospora caninum infections in cattle from the state of Paraíba, Northeastern Brazil, using a planned sampling. Herds (n = 434) and cows aged ≥24 months (n = 1891) were randomly selected, and serum samples were tested with the immunofluorescence antibody test (IFAT) using as cut-off point the antibody titer 200. Herd-level and animal-level seroprevalences were 17.8% (95% CI = 14.3%-21.8%) and 18.1% (95% CI = 14.7%-22.1%), respectively. The factors associated with N. caninum infection were farm located in the Sertão mesoregion (Prevalence ratio [PR] = 2.37), mixed production (PR = 1.64), herd size of 34-111 animals (PR = 3.50) and herd size >111 animals (PR = 6.14). The results indicate high N. caninum circulation in the bovine population of the state of Paraíba, semiarid of Brazil, mainly in the Sertão mesoregion, where the highest apparent herd and animal-level prevalences of positive herds were identified. Control strategies should be adopted to mitigate the impact of disease on cattle production, as well as it's suggested the encouragement of conducting surveys in wildlife from Caatinga biome, mainly canids, to provide information on the importance of these animals on the epidemiology of bovine neosporosis.

Epidemiological aspects of snakebites in the state of Amazonas, Brazil, from 2007 to 2017

This study comprises a retrospective analysis of snakebites in the State of Amazonas, Brazil, from 2007 to 2017. Data were collected from the Notifiable Diseases Information System (NDIS). 17,056 snakebites were recorded in Amazonas between 2007 and 2017. During the study period, the Rio Negro and Tefé micro-regions had the highest accumulated incidence, while small municipalities such as São Gabriel da Cachoeira, Uarini and Alvarães presenting a high incidence rate during the same period. Snakes in the genera Bothrops and Lachesis caused 69.5% and 20.3% snakebites. Snakebites occurred more frequently in the Amazonian winter, between January and April, and most of the snakebite victims (78.6%) were men. The most affected individuals were between 20 and 39 years of age (59.4%). The time elapsed between snakebites and medical assistance varied from one to six hours (51.4%). 7,705 of the snakebite cases, were classified as moderate, 7,328 as mild, and 1,299 as severe. Of the 104 deaths that occurred in the period, Bothrops genus caused the highest mortality (68.3%). The State of Amazonas recorded both high numbers of snakebites in the period 2007-2017 and the time elapsed between snakebite and medical assistance, which may affect the clinical status of patients.

Bayesian estimation of herd-level prevalence and risk factors associated with BoHV-1 infection in cattle herds in the State of Paraíba, Brazil.

A cross-sectional study was carried out to estimate the animal- and herd-level prevalence of bovine herpesvirus 1 (BoHV-1) infection in cattle in the State of Paraíba, and to identify risk factors associated with herd-level infection. The state was divided into three sampling strata, and for each stratum, the prevalence of herds infected with BoHV-1 was estimated through a two-stage sampling survey carried out from September 2012 to January 2013. In total, 2443 animals were sampled from 478 herds. A virus-neutralization test was used for BoHV-1 antibody detection. A Bayesian latent-class model was used to describe the data, taking into account imperfect diagnostic test characteristics and the non-independence of test results from animals within the same herd, and using a dynamic within-model risk factor selection method based on indicator variable selection. The adjusted herd-level prevalence was estimated to be 84% (95% CI: 80-88%) for the State of Paraíba, and the animal-level prevalence was estimated to be 73% (95% CI: 66-84%). Only five of the available risk factors were used by the model, with the three most influential being disposal of aborted foetuses (3.78, 95% CI: 1.11-13.85), sharing resources with other farms (3.0, 95% CI: 1.1-8,6), and a herd size of > 23 animals (2.5, 95% CI: 1.1-6.0). Our findings suggest that the animal- and herd-level seroprevalence of BoHV-1 infection in the State of Paraíba is high. While some risk factors such as herd size and sharing resources were identified as risk factors for BoHV-1 infection, these risk factors are initially likely to be of only minor relevance in a control programme due to the extremely high prevalence of infected farms. However, the results are relevant to the risk of reintroduction of disease on farms that have previously eradicated the disease.

Spatial analysis for bovine viral diarrhea virus and bovine herpesvirus type 1 infections in the state of Paraíba, northeastern Brazil.

BACKGROUND: Bovine Viral Diarrhea Virus (BVDV) and Bovine Herpesvirus type 1 (BoHV-1) cause reproductive problems in cattle and restrictions on international trade in animals worldwide. Both infections were detected in cattle herds in the Paraíba state, Northeastern Brazil, however, the spatial distribution and geographic identification of positive herds for these viruses has never been examined. Therefore, the aim of this study was to describe the spatial pattern of apparent prevalence estimate and to identify spatial clustering of positive herds of BVDV and BoHV-1 infections in cattle herds from the state of Paraíba, Northeastern Brazil. RESULTS: The herd-level prevalence for BVDV and BoHV-1 infections in Paraíba were, respectively, 65.5% (95% CI: 61.1-69.7) and 87.8% (95% CI: 84.5-90.5). The average apparent within-herd prevalence of BVDV was 31.8% and of BoHV-1 was 62.4%. The predicted prevalence was highest (0.42-0.75) for BVDV in the west, north and eastern part of Sertão and in the central and eastern part of Agreste/Zona da Mata. For BoHV-1, the highest predicted prevalence (0.74-0.97) was in some local areas across Sertão and throughout the eastern part of Agreste/Zona da Mata. Six significant clusters were detected for BVDV, a primary cluster covering the eastern Sertão region, with 11 herds, radius of 24.10 km and risk relative (RR) of 2.21 (P <  0.001) and five smaller significant clusters, involving one or two herds in Agreste/Zona da Mata region with a high RR. A significant clustering of BoHV-1 positive herds (P <  0.001) was detected in Agreste/Zona da Mata region with a radius of 77.17 km and a RR of 1.27, with 103 cases. Consistency was found between kriging and SatScan results for identification of risk areas for BVDV and BoHV-1 infections. CONCLUSIONS: The clusters detected contemplated different areas of the state, with BVDV cluster located in the Sertão and BoHV-1 in Agreste/Zona da Mata stratum. Through the risk mapping, it was possible to identify the areas in which the risk is significantly elevated, coincided with areas where there are borders with other states and in which there is a high movement of animals.

Herd-level spatial cluster analysis of bovine cysticercosis in the state of Paraíba, northeastern Brazil.

The aim of this survey was to identify spatial clustering of bovine cysticercosis-positive herds in the state of Paraíba. The state was divided into three sampling groups: sampling stratum 1 (Sertão mesoregion), sampling stratum 2 (Borborema mesoregion) and sampling stratum 3 (Zona da Mata and Agreste mesoregions), and 2382 cows aging ≥ 24 months from 474 farms were sampled. Serological diagnoses of bovine cysticercosis were initially done by means of indirect ELISA, and positive serum samples were confirmed by a immunoblot test. Herds were deemed positive for cysticercosis if they presented at least one positive animal in herds of up to 29 females, and two positive animals in herds with more than 29 females. The spatial clustering was assessed using the Cuzick-Edwards k-nearest neighbor method and spatial scan statistics. A significant clustering of positive herds was detected in the southern part of the Borborema mesoregion. Given that serological tests for bovine cysticercosis are not widely available, and also that replacement and maintenance of herds through animal purchases is common in the region, it can be concluded that prevention measures should be applied at herd level.

Herd-level spatial cluster analysis of bovine cysticercosis in the state of Paraíba, northeastern Brazil / Análise de aglomerados espaciais no nível do rebanho de cisticercose bovina no Estado da Paraíba, Nordeste do Brasil

Abstract The aim of this survey was to identify spatial clustering of bovine cysticercosis-positive herds in the state of Paraíba. The state was divided into three sampling groups: sampling stratum 1 (Sertão mesoregion), sampling stratum 2 (Borborema mesoregion) and sampling stratum 3 (Zona da Mata and Agreste mesoregions), and 2382 cows aging ≥ 24 months from 474 farms were sampled. Serological diagnoses of bovine cysticercosis were initially done by means of indirect ELISA, and positive serum samples were confirmed by a immunoblot test. Herds were deemed positive for cysticercosis if they presented at least one positive animal in herds of up to 29 females, and two positive animals in herds with more than 29 females. The spatial clustering was assessed using the Cuzick-Edwards k-nearest neighbor method and spatial scan statistics. A significant clustering of positive herds was detected in the southern part of the Borborema mesoregion. Given that serological tests for bovine cysticercosis are not widely available, and also that replacement and maintenance of herds through animal purchases is common in the region, it can be concluded that prevention measures should be applied at herd level.

Resumo O objetivo deste estudo foi identificar agrupamentos espaciais de rebanhos positivos para cisticercose bovina no Estado da Paraíba. O estado foi dividido em três grupos amostrais: estrato amostral 1 (mesorregião do Sertão), estrato amostral 2 (mesorregião da Borborema), e estrato amostral 3 (mesorregiões da Zona da Mata e Agreste), e 2.382 vacas com idade ≥ 24 meses foram amostradas a partir de 474 propriedades. O diagnóstico sorológico da cisticercose bovina foi inicialmente realizado pelo ELISA indireto, e as amostras de soro positivas foram confirmadas por immunoblot. Um rebanho foi considerado positivo para cisticercose se apresentasse pelo menos um animal positivo em rebanhos de até 29 fêmeas, e dois animais positivos em rebanhos com mais de 29 fêmeas. Os agrupamentos espaciais foram avaliados com o uso da metodologia k-vizinhos mais próximos de Cuzick-Edwards e estatística espacial de varredura. Um agrupamento significativo de rebanhos positivos foi detectado na parte sul da mesorregião da Borborema. Tendo em vista que os testes sorológicos para diagnóstico de cisticercose bovina não são amplamente disponíveis, bem como é comum na região a reposição e manutenção dos rebanhos por compra de animais, conclui-se que medidas de prevenção devem ser aplicadas em nível de rebanho.

Herd-level prevalence and risk factors for bovine viral diarrhea virus infection in cattle in the State of Paraíba, Northeastern Brazil.

Serological surveys based on a planned sampling on bovine viral diarrhea virus (BVDV) infection in Brazilian cattle herds are scarce. A cross-sectional study was carried out to determine herd- and animal-level seroprevalences and to identify risk factors associated with herd-level seroprevalence for BVDV infection in the State of Paraíba, Northeastern Brazil, from September 2012 to January 2013. The state was divided into three sampling strata, and for each stratum, the prevalence of herds infected with BVDV and the prevalence of seropositive animals was estimated by a two-stage sampling survey. In total, 2443 animals were sampled from 478 herds. A virus-neutralization test was used for BVDV antibody detection. A herd was considered positive when at least one seropositive animal was detected. The herd- and animal-level prevalences in the State of Paraíba were 65.5% (95% confidence interval (CI) = 61.1-69.7%) and 39.1% (95% CI = 33.1-45.6%), respectively. The frequency of seropositive animals per herd ranged from 10 to 100% (median of 50%). The risk factors identified were as follows: more than six calves aged ≤12 months (odds ratio (OR) = 3.72; 95% CI = 2.08-6.66), animal purchasing (OR = 1.66; 95% CI = 1.08-2.55), pasture rental (OR = 2.15; 95% CI = 1.35-3.55), and presence of veterinary assistance (OR = 2.04; 95% CI = 1.10-3.79). Our findings suggest that the implementation of control and prevention measures among farmers, with the aim of preventing dissemination of the agent in the herds, is necessary. Special attention should be given to addressing the identified risk factors, such as sanitary control prior to animal purchasing and to discourage the pasture rental, as well as to encourage the vaccination in the herds.

Epidemiological characterization of leptospirosis in horses in the state of Pernambuco, northeastern Brazil / Caracterização epidemiológica da leptospirose em equinos do estado de Pernambuco, nordeste do Brasil

An epidemiological survey aiming to determine the occurrence of anti-Leptospira antibodies and to identify risk factors was carried out in horses of the Pajeú microregion, state of Pernambuco. Sera from 100 horses from 38 properties in four counties in the region were examined by the microscopic agglutination test (MAT), using 24 Leptospira spp. serovars as antigens. Of the 100 samples tested, 28 (28%) were positive. Most prevalent serovars were Patoc (35.71%), Butembo (32.14%) and Sentot (14.30%). Supply of pasture as forage (odds ratio =7.80; 95% confidence interval - 95%CI 1.71-35.50; p=0.008) was identify as risk factor. It is suggested the need for studies on agent isolation and characterization of its pathogenicity, as well as it is recommended the rodent control in deposits of feed and environment.(AU)

Foi realizado um inquérito epidemiológico objetivando determinar a ocorrência de anticorpos anti-Leptospira e elencar os fatores de risco em equinos da microrregião do Pajeú, estado de Pernambuco. Foram examinados 100 soros de equinos provenientes de 38 propriedades de 4 municípios da região, pela prova de soroaglutinação microscópica (SAM), utilizando 24 sorovares de Leptospira spp. como antígeno. Das 100 amostras testadas, 28 (28%) foram reagentes. Os sorovares mais frequentes foram Patoc (35,71%), Butembo (32,14%) e Sentot (14,30%). O uso de pasto como volumoso (odds ratio =7,80; intervalo de confiança de 95% - IC95% 1,71-35,50; p=0,008) foi identificado como fator de risco. Sugere-se a necessidade de estudos acerca do isolamento do agente e da caracterização de sua patogenicidade, bem como se recomenda o controle de roedores em depósitos de ração e no ambiente.(AU)