Genetic diversity of BCoV in Brazilian cattle herds.

Bovine coronavirus (BCoV) is one of the main aetiological agents of gastroenteritis in calves, causing significant economic damage to livestock. This study aims to characterise BCoV genetically on the basis of the N gene. A total of 114 faecal samples from beef and dairy calves with or without clinical symptoms of diarrhoea from five Brazilian states (São Paulo, Minas Gerais, Santa Catarina, Mato Grosso and Bahia) were evaluated between 2008 and 2015 by technique of Semi-nested RT-PCR for gene N and genealogical analysis. Of the 114 samples analysed, 14.91% (17/114) were positive. BCoV was detected in 22.72% (10/44) of the animals with diarrhoea and in 10% (7/70) of asymptomatic animals. BCoV was identified in calves from rural properties located in all of the regions sampled. Genealogical analysis showed that the Brazilian sequences of BCoV for the gene which codes for the N protein can be broken down into two distinct clusters, and the samples from this study were closely linked to Asian strains. These results contribute to the molecular characterization of BCoV in Brazil and are the first report of the circulation of BCoV in the states of Santa Catarina and Bahia.

Prevalence of Bluetongue virus serotype 4 in cattle in the State of Sao Paulo, Brazil.

Bluetongue (BT) is considered endemic in several regions of Brazil. The State of Sao Paulo was divided into 7 cattle production regions (circuits) according the different systems of breeding, operational and logistical capacity of the state veterinary service. At least 1 animal from each property (a total of 1,716 farms) was tested by competitive ELISA for the presence of antibodies against BTV. Sero­positive sera were subsequently also tested by virus neutralization tests (VNT) using serial dilutions from 1:10 (cutoff) up to 1:640 (in MEM). BTV­4 neutralizing antibodies were detected in 86% (1,483/1,716) of the animals tested. These results show that BTV­4 is endemic and widespread in the State of San Paulo and indirectly confirm that in the State there are favourable conditions for the multiplication of competent vectors. However, as no clinical signs have ever been reported in cattle in the region, BTV­4 infection is likely to occur silently in the State of Sao Paulo.

Outbreak of Bluetongue virus serotype 4 in dairy sheep in Rio de Janeiro, Brazil.

In late January 2013, 10 nonpregnant Lacaune dairy ewes raised under extensive husbandry management on a farm in Rio de Janeiro, Brazil, presented with the general clinical signs of lethargy, hyporexia, edema of the face, hyperemia of the exposed parts of the skin, mouth lesions, pyrexia, and lameness. Additionally, 2 pregnant ewes died suddenly after the onset of respiratory signs. The complete blood counts and biochemistry analyses showed neutrophilic leukocytosis with monocytosis and reactive lymphocytes, normocytic normochromic anemia and increased aspartate aminotransferase levels. Postmortem examination revealed erosions on the lingual mucosa, bilateral submandibular ganglia infarctions, yellow foamy fluid accumulation in the trachea and bronchial bifurcation, pulmonary congestion, and edema associated with hemorrhagic lesions on the pulmonary artery and heart. The clinical and pathological findings were suggestive of bluetongue. For a molecular and virological diagnosis, tissue samples were analyzed by Bluetongue virus-specific real-time reverse transcription polymerase chain reaction (qRT-PCR), and viral isolation was performed in embryonated chicken eggs. For viral typing, positive tissue and egg-isolated samples were analyzed by qRT-PCR using primers and probes specific for the structural VP2 gene in genome segment 2 of all 26 serotypes. There are still no contingency plans for responding to an outbreak of bluetongue disease in Brazil, and this episode emphasizes the need for continuing serological and entomological surveillance programs. Additionally, this report describes the isolation of Bluetongue virus serotype 4 in sheep in the Americas.