A scoping review of African swine fever virus spread between domestic and free-living pigs.

Since 2007, African swine fever virus (ASFV) has spread to countries in Europe, Asia and Oceania and has caused devastating impacts on pigs and the pork industry. Transmission can be direct or indirect, and epidemiologic scenarios have been described in which spread occurs between free-living and domestic pigs. The purpose of this scoping review was to identify primary research in which authors made statements to support ASFV transmission between free-living and domestic pigs and assess the circumstances in which transmission events occurred. A search was conducted in five bibliographic databases and the grey literature. Two reviewers (from a team of ten) independently screened each record and charted data (demographics of the pig populations, their husbandry [domestic pigs] and habitat [free-living pigs], the spatial and temporal distribution of ASF, the occurrence or burden of ASF in the populations, and whether ticks were present in the geographic range of the pig populations). Data synthesis included statistics and a narrative summary. From 1,349 records screened, data were charted from 46 individual studies published from 1985 to 2020. Outbreak investigations revealed that whilst poor biosecurity of domestic pig operations was often reported, direct contact resulting in transmission between free-living and domestic pigs was rarely reported. Studies in which quantitative associations were made generally found that spread within populations was more important than spread between populations, although this was not always the case, particularly when domestic pigs were free-ranging. We conclude that there is limited evidence that transmission of ASFV between free-living and domestic pigs is an important feature of ASF epidemiology, especially in the current ASF epidemic in Europe and the Russian Federation. If ASFV elimination cannot be achieved in free-living pigs, compartmentalization of domestic pig populations from free-living populations via biosecurity strategies could be used to support trade of domestic pigs.

Veterinarians' Knowledge, Attitudes and Practices Associated with Bovine Viral Diarrhoea Virus Control and Prevention in South-East Australia.

In Australia, the responsibility and associated costs for the control and prevention of Bovine Viral Diarrhoea Virus (BVDV) rest solely with producers. Veterinarians provide producers with farm-specific options for BVDV management and support BVDV control and elimination in their region. We surveyed veterinarians to determine their knowledge, attitudes and practices (KAP) associated with BVDV control in south-east Australia. We found that veterinarians' recommendations do not always align with producers' control measures. Veterinarians were uncertain about BVDV prevalence and the proportion of producers using BVDV control measures in their regions. Veterinarians generally promoted biosecurity and vaccination, and were concerned about the welfare and additional disease risks associated with persistently infected (PI) cattle. Veterinarians highlighted concerns about disease risks associated with a previously undocumented practice in which producers collect blood from PI cattle to administer to BVDV naïve cattle; termed "vampire vaccination" in this study. A greater understanding of the burden, impact and economics of BVDV is needed to align veterinarians' and producers' KAP to improve BVDV management on farms, and more appreciation of veterinarians' and producers' values is needed before BVDV control could be implemented at a regional or country level.

Pharmacokinetics of intravenous continuous rate infusions of sodium benzylpenicillin and ceftiofur sodium in adult horses.

OBJECTIVE To determine plasma drug concentrations after IV administration of a bolus followed by continuous rate infusion (CRI) of sodium benzylpenicillin and ceftiofur sodium to healthy adult horses. ANIMALS 6 Thoroughbred mares (3 to 9 years old; mean ± SD body weight, 544 ± 55 kg) with no history of recent antimicrobial treatment. PROCEDURES Horses were used in 2 experiments conducted 14 days apart. For each experiment, horses were housed individually in stables, and catheters were placed bilaterally in both jugular veins for drug administration by CRI (left catheter) and for intermittent collection of blood samples (right catheter). Synovial fluid samples were obtained from carpal joints following ceftiofur administration to evaluate drug diffusion into articular spaces. RESULTS Plasma concentrations above accepted minimum inhibitory concentrations for common pathogens of horses were achieved within 1 minute after bolus administration and remained above the minimum inhibitory concentration for 48 (ceftiofur) or 12 (benzylpenicillin) hours (ie, the duration of the CRI). Mean synovial fluid ceftiofur free acid equivalent concentrations were approximately 46% (range, 25.4% to 59.8%) of plasma concentrations at the end of infusion. CONCLUSIONS AND CLINICAL RELEVANCE Compared with intermittent bolus administration, the loading dose and CRI used less drug but maintained high plasma concentrations for the duration of infusion. By use of pharmacological parameters derived in this study, a loading dose of 2.5 mg/kg and CRI of 200 µg/kg/h should achieve plasma ceftiofur concentrations of 4 µg/mL; a loading dose and CRI of 1.3 mg/kg and 2.5 µg/kg/h, respectively, should achieve plasma benzylpenicillin concentrations of 2 µg/mL.