ABSTRACT
This study aimed to survey captive wild boars for antibodies against Porcine circovirus-2 (PCV-2) in registered farms. Serum samples (n = 1305) were collected from 90-day-old wild boars from 118 farms of the Brazilian South-east region, including the states of Minas Gerais and São Paulo, and South region, including the states of Paraná, Rio Grande do Sul and Santa Catarina. All herds (100%) presented reactive animals, in varying numbers and from low-to-high antibody titres, with the occurrence ranging from 82 to 89%. Considering farms, the average prevalence was of 84.9% (P < 0.05) and ranged from 54.1 to 94.95%. Regarding the geographic regions studied, the prevalence was of 100%, with PCV2 antibodies detected in wild boars of all regions. This study provides the first evidence of PCV2 antibodies in captive wild boars in Brazil.
Subject(s)
Circoviridae Infections/epidemiology , Circovirus/isolation & purification , Sentinel Surveillance/veterinary , Agriculture , Animals , Animals, Wild/virology , Antibodies, Viral/blood , Brazil/epidemiology , Circoviridae Infections/blood , Circoviridae Infections/virology , Circovirus/immunology , Prevalence , Surveys and Questionnaires , Sus scrofa/virology , SwineABSTRACT
Reversible pressure-induced disassembly of several viruses has suggested the idea of using hydrostatic pressure to suppress virus infectivity. In this study, the effects of high hydrostatic pressure and ultraviolet (UV) irradiation were investigated on classical swine fever virus (CSFV) in an attempt to eliminate residual infectivity. The structural modifications were followed by intrinsic fluorescence and biological activity assays. The kinetics of CSFV inactivation showed that pressure-induced inactivation was not enough to eliminate viral infectivity. However, when pressure was applied in association with UV irradiation no infectious focus was observed. The application of these two methods against CSFV can be an attractive inactivation strategy for the development of a vaccine.
Subject(s)
Classical Swine Fever Virus/radiation effects , Animals , Cell Line , Classical Swine Fever/prevention & control , Classical Swine Fever Virus/isolation & purification , Classical Swine Fever Virus/pathogenicity , Hydrostatic Pressure , In Vitro Techniques , Kinetics , Light , Scattering, Radiation , Spectrometry, Fluorescence , Sus scrofa , Ultraviolet Rays , Vaccines, Attenuated/isolation & purification , Viral Vaccines/isolation & purification , Virus Inactivation/radiation effectsABSTRACT
1. Wild stable flies (stomoxys calcitrans) feeding on heifers infected with bovine leukosis virus (BLV) carried viable bovine leucocytes in the midgut and proboscis that, when inoculated by the subcutaneous route into lambs aged 5 to 60 days, elicited the development of antibodies to glycoprotein (gp51) and polipeptide 25 (p25). 2. Antibodies were detected as early as one month later and persisted for an experimental period of 24 or 36 months. Uninoculated control lambs reared to gether with the experimental animals did not acquire the infection, indicating the lack of horizontal transmission. 3. S. calcitrans reared in the laboratory were intermittently allowed to feed on the skin of BLV-infected heifers and on five lambs over a period of 3-10 months. Although some of these lambs were bitten about 500 times, none developed antibodies to BLV (gp51 or p25) over observation periods of 30 or 36 months