Risk factors for foot-and-mouth disease in Zambia, 1981–2012

The aim of this study was to describe the spatial distribution of foot-and-mouth disease (FMD) outbreaks in Zambia for the period January 1981–December 2012 and to quantify the association between geographical features (proximity to roads, national parks, wetland areas) and the spatial distribution of FMD using a Poisson point process model.     

Multiple introductions of serotype O foot-and-mouth disease viruses into East Asia in 2010–2011

Foot-and-mouth disease virus (FMDV) is a highly contagious and genetically variable virus. Sporadic introductions of this virus into FMD-free countries may cause outbreaks with devastating consequences. In 2010 and 2011, incursions of the FMDV O/SEA/Mya-98 strain, normally restricted to countries in mainland Southeast Asia, caused extensive outbreaks across East Asia. In this study, 12 full genome FMDV sequences for representative samples collected from the People’s Republic of China (PR China) including the Hong Kong Special Administrative Region (SAR), the Republic of Korea, the Democratic People’s Republic of Korea, Japan, Mongolia and The Russian Federation were generated and compared with additional contemporary sequences from viruses within this lineage. These complete genomes were 8119 to 8193 nucleotides in length and differed at 1181 sites, sharing a nucleotide identity ≥ 91.0% and an amino acid identity ≥ 96.6%. An unexpected deletion of 70 nucleotides within the 5′-untranslated region which resulted in a shorter predicted RNA stem-loop for the S-fragment was revealed in two sequences from PR China and Hong Kong SAR and five additional related samples from the region. Statistical parsimony and Bayesian phylogenetic analysis provide evidence that these outbreaks in East Asia were generated by two independent introductions of the O/SEA/Mya-98 lineage sometime between August 2008 and March 2010. The rapid emergence of these viruses from Southeast Asia highlights the importance of adopting approaches to closely monitor the spread of this lineage that now poses a threat to livestock industries in other regions.     

Temporal-spatial epidemiology of foot-and-mouth disease outbreaks in Mongolia, 2000 – 2002

Prior to 2000, foot-and-mouth disease (FMD) had not been observed in Mongolia since 1973; however, between April 2000 and July 2002, Mongolia reported 44 FMD outbreaks that affected cattle, sheep, goats, and camels. The objectives of this study were to describe the distributions of the 44 reported FMD outbreaks in Mongolia and to assess their spatial clustering and directions of movement. Official reports were collected to obtain the number and species of animals both affected and at risk, and the date and geographical coordinates of each outbreak. Significant global and local spatial clusters of reported FMD outbreaks were identified. Disease spread during the second epidemic moved 76° northeast and the spread of the disease during the third epidemic moved 110° northwest. FMD outbreaks were clustered intensely close to other FMD-positive counties. These findings can be used in the future to help plan prevention and control measures in high risk areas.     

The expressions of HSP70 and ��B-crystallin in myocarditis associated with foot-and-mouth disease virus in lambs

This study describes the expression of heat shock protein70 (HSP70) and alpha-basic-crystallin (α-BC) and their association with apoptosis and some related adaptor proteins in the pathogenesis of foot-and-mouth disease virus (FMDV)-induced myocarditis in lambs. HSP70 was generally overexpressed in the myocardial tissues and inflammatory cells of FMDV-induced myocarditis with differential accumulation and localization in same hearts when compared to non-foot-and-mouth disease control hearts. α-BC immunolabeling showed coarse aggregations in the Z line of the cardiomyocytes in FMDV-infected hearts in contrast to control hearts. Overall, the results of this study show that the anti-apoptotic proteins, HSP70 and α-BC, were overexpressed with increased apoptosis in FMDV-infected heart tissues. Both proteins failed to protect the cardiomyocytes from apoptosis as defense mechanisms to the FMDV during the infection, suggesting that the virus is able to increase apoptosis via both downregulation and/or upregulation of these anti-apoptotic proteins.     

Drivers and risk factors for circulating African swine fever virus in Uganda, 2012–2013

We explored observed risk factors and drivers of infection possibly associated with African swine fever (ASF) epidemiology in Uganda. Representative sub-populations of pig farms and statistics were used in a case-control model. Indiscriminate disposal of pig viscera and waste materials after slaughter, including on open refuse dumps, farm-gate buyers collecting pigs and pig products from within a farm, and retention of survivor pigs were plausible risk factors. Wire mesh-protected windows in pig houses were found to be protective against ASF infection. Sighting engorged ticks on pigs, the presence of a lock for each pig pen and/or a gate at the farm entrance were significantly associated with infection/non-infection; possible explanations were offered. Strict adherence to planned within-farm and community-based biosecurity, and avoidance of identified risk factors is recommended to reduce infection. Training for small-scale and emerging farmers should involve multidimensional and multidisciplinary approaches to reduce human-related risky behaviours driving infection.     

Prevalence and spectrum of Johne’s disease lesions in cattle slaughtered at two abattoirs in Kampala, Uganda

This study was conducted to determine the prevalence and characteristics of Johne’s disease (JD) lesions in Ugandan cattle slaughtered at two of the main abattoirs in Kampala. Ileocaecal junction and the associated lymph nodes of 1,022 cattle were examined for gross and microscopic lesions, followed by Ziehl Neelsen staining of the tissues bearing lesions. Confirmation of Mycobacterium avium subsp. paratuberculosis infection was done in some of the tissues using culture and IS900 PCR. The lesions were then described, characterised and tabulated. Characteristic Johne’s disease granulomas were found in 4.7% of the samples examined, derived from Zebu, Ankole longhorn, Friesian breeds of cattle and their crosses. Lesions were found both in the lymph nodes and ileocaecal junction mucosa. The lesions tended to be more severe in the lymph node than in the mucosa. There were also some unique and atypical lesions found in association with Johne’s disease granulomas. The diagnostic values of various gross lesions and criteria of lesion classifications and diagnosis are revisited and discussed based on the findings of this study. The prevalence of Johne’s disease lesions among slaughtered cattle in Kampala’s two abattoirs indicates that the disease is well established in the cattle population in the country. The diverse manifestations in lesions of JD need to be considered when making histological diagnosis in tissues where the disease is suspected.     

Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010

Background

Previous studies have reported a seasonal increased risk for leptospirosis, but there is no consistent seasonality reported across regions in the United States.

Objectives

To evaluate and compare seasonal patterns in seropositivity for leptospirosis in dogs for 4 US regions (northeast [NE], midwest [MW], south‐central [SC], and California‐southern west coast [CS]).

Animals

Forty four thousand nine hundred and sixteen canine serum samples submitted to a commercial laboratory for microscopic agglutination tests (MAT) from 2000 through 2010.

Methods

In this retrospective study, positive cases were defined as MAT titers ≥1 : 3,200 for at least one of 7 tested serovars. Four geographic regions were defined, and MAT results were included in regional analyses based on hospital zipcode. A seasonal‐trend decomposition method for times series was utilized for the analysis. Monthly variation in the seropositive rate was evaluated using a seasonal cycle subseries plot and logistic regression.

Results

Two thousand and twelve of 44,916 (4.48%) samples were seropositive. Compared to seropositive rates for February, significantly higher monthly rates occurred during the 2nd half of the year in the MW (OR 3.92–6.35) and NE (OR 2.03–4.80) regions, and only in January (OR 2.34) and December (OR 1.74) in the SC region. Monthly seropositive rates indicative of seasonality were observed earlier in the calendar year for both CS and SC regions.

Conclusions and Clinical Importance

Seasonal patterns for seropositivity to leptospires differed by geographic region. Although risk of infection in dogs can occur year round, knowledge of seasonal trends can assist veterinarians in formulating differential diagnoses and evaluation of exposure risk.     

Immunoproteomic analysis of the protective response obtained with subunit and commercial vaccines against Glässer's disease in pigs

An immunoproteomic analysis of the protective response of subunit and commercial vaccines in colostrum-deprived pigs against Glässer's disease was carried out. A mixture of proteins with affinity to porcine transferrin (PAPT) from Haemophilus parasuis Nagasaki strain (serovar 5) was inoculated intramuscularly (PAPT_M) and intratracheally (PAPT_Cp), along with a commercial bacterin. PAPT were separated using 2 dimensional electrophoresis (2DE) gels and with them, 2DE Western blots were carried out. A total of 17 spots were identified as positive with sera of pigs from any of the three vaccinated groups, the highest number of immunoreactive proteins being detected in those having received PAPT_Cp. Among them, six proteins (FKBP-type peptidyl-prolyl cis-trans isomerase, neuraminidase exo-α-sialidase, xanthine-guanine phosphoribosyl transferase, CMP-N-acetylneuraminic acid synthetase, phenylalanyl-tRNA synthetase and glyceraldehyde 3-phosphate dehydrogenase) were found to be novel immunogens in H. parasuis. These proteins showed a high potential as candidates in future subunit vaccines against Glässer's disease. The three experimental groups developed specific systemic total IgG (IgGt), IgG1, IgG2 and IgM antibodies after immunizations. In addition, those receiving PAPT_Cp yielded a serum IgA response.     

Is there a benefit from an early booster vaccination in the control of equine influenza?

Conventional equine influenza vaccination schedules consist of a primary course of two vaccinations given 4-6 weeks apart followed by a third vaccination (booster) given approximately 5 months later. In between the primary course and the third vaccination, horses are generally considered not to be adequately protected against influenza. This study aimed to investigate whether Thoroughbred foals would benefit from a vaccination schedule in which the third vaccination was given earlier than in conventional vaccination schedules. The vaccines used were an inactivated whole virus equine influenza vaccine and an inactivated whole virus combination vaccine containing equine influenza and equine herpesvirus antigens. Four groups of foals were vaccinated with the two vaccines according to a conventional and an accelerated vaccination schedule in which the third vaccination was given 14 weeks after the first administration. In both groups, the fourth vaccination was given at the normally recommended interval of 26 weeks after the third vaccination for the combination vaccine and 52 weeks after the third vaccination with the influenza only vaccine. The horses were 4-11 months of age and seronegative for influenza. Immunological responses after vaccination were monitored for several months using the single radial haemolysis test. The results indicated that 28 weeks after the first vaccination, antibody levels in horses vaccinated according to the accelerated schedule were not significantly higher than in horses vaccinated according to the conventional schedule. In addition, the total level of antibody production (area under the curve) was not significantly different at that point although antibody titres were slightly higher (but not significantly so) between 16-30 weeks in the accelerated schedule. Between the third and fourth doses, horses vaccinated according to the accelerated schedule had antibodies against influenza below the level required for clinical protection for 39 and 18 weeks for the influenza only and the combination vaccine, respectively, whereas those vaccinated according to the conventional schedule had antibody titres below the level for clinical protection for 9-15 weeks in the corresponding period for both vaccines. Horses vaccinated according to the accelerated schedule with the combination vaccine had lower antibody titres after the fourth vaccination than those vaccinated according to the conventional schedule after the third vaccination, although antibody titres prior to vaccination were similar. For the influenza only vaccine, titres after the accelerated fourth administration were not different to those after the conventional third vaccination. There was no benefit from early booster vaccinations with the vaccines used in this study, so for these vaccines the conventional schedule provided better protection than the selected accelerated alternative. This may contrast with some other vaccine formulations, although a direct comparison using similar protocols has not been made.     

Comparison of lidocaine,tramadol, and lidocaine–tramadol for epidural analgesia in lambs

Epidural anesthesia is commonly utilized in veterinary medicine to allow diagnostic, obstetrical, and surgical intervention, in the perineal region of domestic animal. The following study was carried out to directly compare the time of onset and duration of anesthesia produced by a tramadol and lidocaine–tramadol combination with that produced by lidocaine administration in the epidural space of lamb. Seven healthy female lambs of undefined breed weighing 15–20 kg were selected for this study. Epidural anesthesia was produced in all lambs by 2% lidocaine and with 2 weeks intervals repeated by combination of lidocaine–tramadol and tramadol alone. Analgesia was defined as lack of a response to pin prick test and pressure from hemostat clamp (closed to the first ratchet) applied first in the perineal area and then moved cranially toward the thoracic region until a response (movement associated with pin prick test or hemostat pressure) was observed. Time to onset, duration and cranial spread of analgesia were recorded. Heart rate (HR), respiratory rate (RR), and rectal temperature were recorded before (baseline, 0) and at 15, 30, 45, 60, 75, 90, 105 and 120 min after epidural administration of the solution. The results were expressed as mean ± SD and were analyzed by a one-way analysis of variance and Duncan’s test as a post hoc for heart rate, respiratory rate and body temperature and also, for time of onset and duration of analgesia. Graphpad Prism version 5 software program was used for all analyses. A value of P < 0.05 was considered significant. The tramadol produced a significant (P < 0.05) longer duration of analgesia than lidocaine alone and lidocaine–tramadol combination. Also, lidocaine–tramadol combination produced a significant (P < 0.05) longer duration of analgesia than lidocaine alone. Complete analgesia began more delayed in the tramadol treatment than lidocaine–tramadol and lidocaine alone. The combination of lidocaine–tramadol produced analgesia of longer duration than lidocaine and onset time was approximately same as lidocaine group.     

Expressions of cytochrome P450 aromatase and anti-Müllerian hormone in testes of fattening pigs by the timing of the first vaccination for immunocastration

In practice, two injections of gonadotropin-releasing hormone (GnRH) vaccine are recommended for pig immunocastration for effective outcomes. The present study aimed to investigate the expressions of cytochrome P450 aromatase (P450_arom) and anti-Müllerian hormone (AMH) in testes, testicular length and testicular histomorphometry of the fattening pigs receiving the first injection of GnRH vaccine 6 weeks earlier than the standard protocol. Based on vaccination protocol, 24 pigs were equally divided into three groups: T1 was vaccinated at 15 and 19 weeks of age, T2 received vaccine at 9 and 19 weeks of age and C remained intact. P450_arom and AMH expressions were analysed using immunohistochemistry and Western blot. The results revealed that testicular length was highest in C pigs, but not different between T1 and T2 groups (6.5 ± 0.2 versus 6.9 ± 0.3 cm, p = .538). Histomorphometry demonstrated that the height of spermatogenic epithelia, the diameter of seminiferous tubules and the number of seminiferous tubules between T1 and T2 groups were not different (p > .05). For P450_arom, immunohistochemistry revealed that H-score of C group was significantly higher than that of both T1 and T2 groups. Western blot analysis showed that C group possessed the densest protein band. Moreover, H-score between T1 and T2 groups was not significantly different. Protein band intensity between both groups was not apparently different. As for AMH, C pigs had significantly lower H-score than both T1 and T2 pigs. Furthermore, T2 pigs possessed significantly higher H-score than T1 pigs. Western blot analysis showed that the most intense protein band was found in T2 group. In summary, GnRH vaccine affected testicular development and functions. The first injection could be performed either at 9 or 15 weeks of age since both protocols contributed to comparable results in aspect of testicular length, histomorphometry and expressions of P450_arom and AMH.     

Extensive antigenic and genetic variation among foot-and-mouth disease type A viruses isolated from the 1994 and 1995 foci in S?o Paulo, Brazil.

Nine foot-and-mouth disease virus (FMDV) type A isolates recovered from the field FMD foci in S?o Paulo State, Brazil, during 1994 and 1995 (a period preceding the last reported focus of FMD in 1996 in this state) were compared among themselves and with the reference vaccine strain A(24)Cruzeiro. The techniques used were sandwich ELISA, virus neutralization (VN), polyacrylamide gel electrophoresis (PAGE) of the structural polypeptides and direct sequencing of the VP1-coding region (1D gene). Results of VN were recorded as serological relationships "R" and those from ELISA were expressed as percentage of the homologous reaction "r". ELISA and VN gave comparable results (correlation coefficient, 0.936) allowing assignment of these field viruses to four groups which were distinct from the A(24)Cruzeiro strain. PAGE and 1D nucleotide sequencing were also able to distinguish between these viruses. The high level of genetic and antigenic variation found when comparing the A(24)Cruzeiro vaccine strain and type A strains recovered from the last identified foci of FMD came from a formerly endemic area where vaccination with polyvalent vaccines (O(1)Campos, A(24)Cruzeiro and C(3)Indaial) had been extensively applied. The similarity between the results of the serological and genetic analyses suggest that the antigenic differences found are mainly located in the 1D protein.     

Research and implementation of novel approaches for the control of nematode parasites in Latin America and the Caribbean: is there sufficient incentive for a greater extension effort?

The widespread presence of anthelmintic resistant gastrointestinal parasitic nematodes in outdoor ruminant production systems has driven the need to identify and develop novel approaches for the control of helminths with the intention to reduce the dependence on commercial anthelmintic drugs. This paper identifies what has been done in Latin America (LA) in terms of estimating the prevalence of anthelmintic resistance (AR) in ruminant production systems and the application of different novel approaches for the control of helminths in those systems, including research and extension activities. Firstly, the paucity of knowledge of AR is discussed in the context of different countries, as well as, the available economic resources for research, the technical infrastructure available and the practical difficulties of the production systems. It is then proposed that the search for novel approaches is not only driven by AR but also by the need for techniques that are feasible for application by resource-poor farmers in non-commercial subsistence farming systems. However, the commercial benefits of these approaches are often limited and so are funding inputs in most countries. The workers participating in the research into different novel approaches are identified as well as the different methods being studied in the different areas of LA according to their published results. In addition, the difficulties experienced during extension efforts to reach farmers and help them to adopt novel approaches for the control of parasitic nematodes in LA are discussed. The role of regulatory authorities in these countries is discussed as some methods of control might need an official confirmation of their efficacy as well as authorization prior to application as they may affect animal products (i.e. residues) and/or impose a hazard for animal welfare. The role of the pharmaceutical companies is also discussed.     

Serological status of Canadian cattle for brucellosis,anaplasmosis, and bluetongue in 2007–2008

A national bovine serological survey was conducted to confirm that the prevalence of brucellosis, bluetongue, and anaplasmosis does not exceed 0.02% (95% confidence) in live cattle in Canada. Sampling consisted of a systematic random sample of 15 482 adult cattle slaughtered in federally inspected abattoirs, stratified by province. Samples were tested to detect antibodies for brucellosis, bluetongue, and anaplasmosis. All samples were negative for brucellosis. Three samples were seroreactors to bluetongue, 2 of which originated from the Okanagan Valley in British Columbia and 1 from Ontario, which after follow-up, was considered an atypical result. A total of 244 samples were seroreactors to Anaplasma and follow-up identified infection in Saskatchewan, Manitoba, and Quebec. In conclusion, the Canadian cattle population remains free of brucellosis and free of bluetongue outside the Okanagan Valley. Canada is no longer free of anaplasmosis and will be unable to claim freedom until eradication measures are completed.     

Comparison of lidocaine and lidocaine–epinephrine for the paravertebral brachial plexus block in dogs

Objective

To compare the motor and sensory block efficacy and duration of a modified paravertebral brachial plexus block (PBPB) after administration of lidocaine alone (LI) or combined with epinephrine (LE).