The objective of the present study was to evaluate polyclonal- and monoclonal-antibody-based immunohistochemical (IHC) tests for the detection of 2 genotypes of Porcine circovirus type 2 (PCV2), a and b, in formalin-fixed, paraffin-embedded lymph-node tissue from pigs with experimental or natural postweaning multisystemic wasting syndrome and to compare the IHC results with those of in-situ hybridization (ISH) assays. The ISH assays proved more sensitive than the IHC tests for the detection of PCV2a and PCV2b. According to these findings, polyclonal-antibody-based IHC testing is the most practical routine diagnostic method for the detection of PCV2 regardless of genotype because IHC testing is less technically complex than ISH testing. However, ISH assays are useful to differentiate between PCV2a and PCV2b in surveillance programs for the monitoring of PCV2 in swine herds.

An antigen-capture, monoclonal-antibody-based enzyme-linked immunoassay (ELISA) that detects a broad range of Salmonella serovars in various serogroups was developed and compared with standard culture procedures for detection of Salmonella in 1055 field samples collected from poultry-hatchery environments. The diagnostic sensitivity of the ELISA relative to culture was 99.9% and the diagnostic specificity 99.6%. The extensive culture procedure included nonselective enrichment (NSE) as well as primary selective enrichment (PSE) and delayed secondary enrichment (DSE) with Hajna tetrathionate (TT) and Rappaport-Vassiliadis (RV) selective-enrichment broths. Significantly more Salmonella-positive samples were detected by ELISA and culture at the DSE stage than at the NSE and PSE stages (P < 0.05). Significantly more RV than TT broths were positive for Salmonella by culture and ELISA by the DSE stage (P < 0.05). This ELISA procedure could be a reliable screening test for the detection of Salmonella in hatchery samples.

Objective—To quantify the 3-D kinematics and collateral ligament strain of stifle joints in cadaveric canine limbs before and after cranial cruciate ligament transection followed by total knee replacement (TKR) involving various tibial plateau angles and spacer thicknesses. Sample—6 hemi-pelvises collected from clinically normal nonchondrodystrophic dogs (weight range, 25 to 35 kg). Procedures—Hemi-pelvises were mounted on a modified Oxford knee rig that allowed 6 degrees of freedom of the stifle joint but prevented mechanical movement of the hip and tarsal joints. Kinematics and collateral ligament strain were measured continuously while stifle joints were flexed. Data were again collected after cranial cruciate ligament transection and TKR with combinations of 3 plateau angles (0°, 4°, and 8°) and spacer thicknesses (5, 7, and 9 mm). Results—Presurgical (ie, normal) stifle joint rotations were comparable to those previously documented for live dogs. After TKR, kinematics recorded for the 8°, 5-mm implant most closely resembled those of unaltered stifle joints. Decreasing the plateau angle and increasing spacer thickness altered stifle joint adduction, internal rotation, and medial translation. Medial collateral ligament strain was minimal in unaltered stifle joints and was unaffected by TKR. Lateral collateral ligament strain decreased with steeper plateau angles but returned to a presurgical level at the flattest plateau angle. Conclusions and Clinical Relevance—Among the constructs tested, greatest normalization of canine stifle joint kinematics in vitro was achieved with the steepest plateau angle paired with the thinnest spacer. Furthermore, results indicated that strain to the collateral ligaments was not negatively affected by .

Canine distemper is a highly contagious disease with high incidence and lethality in the canine population. The objective of this study was to evaluate the efficacy of antiviral action with ribavirin (RBV), interferon-alpha (IFNa), and combinations of RBV and IFN a against canine distemper virus (CDV). Vero cells inoculated with CDV were treated with RBV, IFNa, and combinations of these drugs. The efficacy to inhibit viral replication was evaluated by adding the compounds at different times to determine which step of the viral replicative process was affected. Both drugs were effective against CDV in vitro. The IFNa was the most active compound, with an average IC50 (50% inhibitory concentration) value lower than the IC50 of the RBV. Ribavirin (RBV) was more selective than IFN a, however, and neither drug showed extracellular antiviral activity. The combination of RBV and IFN a exhibited antiviral activity for the intra- and extracellular stages of the replicative cycle of CDV, although the intracellular viral inhibition was higher. Both RBV and IFN a showed high antiviral efficacy against CDV, and furthermore, RBV 1 IFNa combinations have shown greater interference range in viral infectivity. These compounds could potentially be used to treat clinical disease associated with CDV infection.

Haemoparasite infections are among the most economically important cattle diseases in sub-Saharan Africa. The present study investigated the occurrence of haemoparasites in 295 indigenous cattle from five villages (Mswakini, Lake Manyara, Naitolia, Makuyuni and Nanja) of the Monduli district, a wildlife-domestic animal-human interface area in northern Tanzania. The data showed that the overall occurrence of haemoparasites in the sampled cattle was 12.5% (95% CI: 8.7% – 16.3%), involving single and mixed infections with Theileria parva, Anaplasma marginale, Babesia bovis, Trypanosoma vivax and Trypanosoma brucei. The highest haemoparasite occurrence was recorded in Lake Manyara (18.3%; 95% CI: 8.5% – 28.1%), and the lowest was recorded in Nanja (6.5%; 95% CI: 0.4% – 12.6%). This preliminary study, furthermore, provided evidence of the possible arthropod vectors (ticks and tsetse flies) that may be involved in the transmission of haemoparasites to cattle in the Monduli district. It is envisaged that this survey will stimulate more studies to determine the prevalence of haemoparasites in livestock by using more sensitive molecular techniques.

Phylogeography data are of paramount importance in studying the molecular epidemiology dynamics of foot-and-mouth disease virus (FMDV). In this study, epithelial samples and oesophageal-pharyngeal fluids were collected from 361 convalescent animals (cattle and buffaloes) in the field throughout Tanzania between 2009 and 2013. The single plex real-time RT-PCR (qRT-PCR) assay for rapid and accurate diagnosis of FMDV employing the Callahan 3DF-2, 3DF-R primers and Callahan 3DP-1 probe were used. Preparation of the samples was performed according to the OIE manual, with a Kenya O serotype obtained from the attenuated vaccine serving as a positive control and samples collected from healthy animals serving as true negatives. The results indicated that 53.49% of samples (n = 176) were positive for FMDV genome by qRT-PCR, with Ct values ranging from 14 to 32. In addition, molecular typing of the FMDV genome positive samples using serotype specific primers revealed the existence of several serotypes: serotype South Africa Territory 1 (SAT1) (34.25%, n = 60), serotype A (68.92%, n = 98), serotype O (59.20%, n = 98) and SAT2 (54.54%, n = 96). The virus protein 1 sequences analysis for 35 samples was performed and the collective results indicated: 54.28% serotype O, 25.71% serotype A, 14.28% serotype SAT1 and 2.85% serotype SAT2. Therefore in this study, both the phylogenetic trees and spatial distribution of serotypes elucidated the phylodynamics of multiple FMDV field strains in Tanzania and neighbouring countries.

Ijara district in Kenya was one of the hotspots of Rift Valley fever (RVF) during the 2006/2007 outbreak, which led to human and animal deaths causing major economic losses. The main constraint for the control and prevention of RVF is inadequate knowledge of the risk factors for its occurrence and maintenance. This study was aimed at understanding the perceived risk factors and risk pathways of RVF in cattle in Ijara to enable the development of improved community-based disease surveillance, prediction, control and prevention. A cross-sectional study was carried out from September 2012 to June 2013. Thirty-one key informant interviews were conducted with relevant stakeholders to determine the local pastoralists’ understanding of risk factors and risk pathways of RVF in cattle in Ijara district. All the key informants perceived the presence of high numbers of mosquitoes and large numbers of cattle to be the most important risk factors contributing to the occurrence of RVF in cattle in Ijara. Key informants classified high rainfall as the most important (12/31) to an important (19/31) risk factor. The main risk pathways were infected mosquitoes that bite cattle whilst grazing and at watering points as well as close contact between domestic animals and wildlife. The likelihood of contamination of the environment as a result of poor handling of carcasses and aborted foetuses during RVF outbreaks was not considered an important pathway. There is therefore a need to conduct regular participatory community awareness sessions on handling of animal carcasses in terms of preparedness, prevention and control of any possible RVF epizootics. Additionally, monitoring of environmental conditions to detect enhanced rainfall and flooding should be prioritised for preparedness.

African swine fever (ASF) is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV), a deoxyribonucleic acid (DNA)arbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% – 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR) that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country’s proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.