Force of infection of Middle East respiratory syndrome in dromedary camels in Kenya.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic disease transmitted from dromedary camels to people, which can result in outbreaks with human-to-human transmission. Because it is a subclinical infection in camels, epidemiological measures other than prevalence are challenging to assess. This study estimated the force of infection (FOI) of MERS-CoV in camel populations from age-stratified serological data. A cross-sectional study of MERS-CoV was conducted in Kenya from July 2016 to July 2017. Seroprevalence was stratified into four age groups: <1, 1-2, 2-3 and >3 years old. Age-independent and age-dependent linear and quadratic generalised linear models were used to estimate FOI in pastoral and ranching camel herds. Models were compared based on computed AIC values. Among pastoral herds, the age-dependent quadratic FOI was the best fit model, while the age-independent FOI was the best fit for the ranching herd data. FOI provides an indirect estimate of infection risk, which is especially valuable where direct estimates of incidence and other measures of infection are challenging to obtain. The FOIs estimated in this study provide important insight about MERS-CoV dynamics in the reservoir species, and contribute to our understanding of the zoonotic risks of this important public health threat.

Are GnRH and FSH potentially damaging factors in the cardiovascular system?

In the physiological view the human cardiomyocytes express receptors of gonadotropin-releasing hormone and follicle-stimulating hormone. The local effects of these hormones in the heart are related also to some interstitial cells, such as endothelial cells with follicle-stimulating hormone receptors and immune cells with gonadotropin-releasing hormone receptors. The administration of androgen deprivation therapy in patients with prostate cancer is associated with increased incidence of cardiovascular complications. It is suggested that negative action of this therapy on cardiovascular system is due to the loss of testosterone but also levels of gonadotropin-releasing hormone and follicle-stimulating hormone are changed by therapy. In this article we review the literature to date with an emphasis on recent investigation focused on potential role of abnormal gonadotropin-releasing hormone and follicle-stimulating hormone levels induced by gonadotropin-releasing hormone agonists on the cardiovascular risk. These facts exacerbate the complexity of specific hormone and cell relationships within heart and vessels. Androgen deprivation therapy reveals the physiological relationships between hormones and specific tissues that are not part of the endocrine system.

Herd-level prevalence and incidence of porcine epidemic diarrhoea virus (PEDV) and porcine deltacoronavirus (PDCoV) in swine herds in Ontario, Canada.

Porcine epidemic diarrhoea virus (PEDV) and porcine deltacoronavirus (PDCoV) were first identified in Canada in 2014. Surveillance efforts have been instrumental in controlling both diseases. In this study, we provide an overview of surveillance components for the two diseases in Ontario (Canada), as well as PEDV and PDCoV incidence and prevalence measures. Swine herds located in the Province of Ontario, of any type, whose owners agreed to participate in a voluntary industry-led disease control programme (DCP) and with associated diagnostic or epidemiological information about the two swine coronaviruses, were eligible to be included for calculation of disease frequency at the provincial level. PEDV and PDCoV data stored in the industry DCP database were imported into the R statistical software and analysed to produce weekly frequency of incidence counts and prevalence counts, in addition to yearly herd-level incidence risk and prevalence between 2014 and 2016. The yearly herd-level incidence risk of PEDV, based on industry data, was 13.5%, 3.0% and 1.4% (95% CI: 11.1-16.2, 2.0-4.2, 0.8-2.3), while the yearly herd-level incidence risk of PDCoV was 1.1%, 0.3%, and 0.1% (95% CI: 0.5-2.2, 0.1-0.9, 0.0-0.5), for 2014, 2015 and 2016, respectively. Herd-level prevalence estimates for PEDV in the last week of 2014, 2015 and 2016 were 4.4%, 2.3% and 1.4%, respectively (95% CI: 3.1-6.0, 1.5-3.3, 0.8-2.2), while herd-level prevalence estimates for PDCoV in the last week of 2014, 2015 and 2016 were 0.5%, 0.2% and 0.2%, respectively (95% CI: 0.1-1.2, 0.0-0.6, 0.0-0.6). Collectively, our results point to low and decreasing incidence risk and prevalence for PEDV and PDCoV in Ontario, making both diseases possible candidates for disease elimination at the provincial level.

Influence of microclimate conditions on the cumulative exposure of nursery pigs to swine influenza A viruses.

The objective of this study was to investigate the association between environmental temperature and humidity and the presence of antibodies for two specific strains of swine influenza viruses: A/SW/ON/105-56/12/H3N2 (H3N2_D) and A/SW/ON/84/2012/H1N1 (H1N1_P). A cross-sectional study was performed in a commercial farm, and a total of 450 pigs at 10 weeks of age were blood sampled, by sampling 10 pigs per week for 45 weeks corresponding to 45 batches. Exposure of pigs to H3N2_D and H1N1_P virus was assessed by haemagglutination inhibition assay (HI), and a result of ≥1:40 was considered as indication of a positive exposure status for a specific strain. The selection of those two viruses was based on the fact that H1N1 was the dominant virus in Ontario herds, and H3N2 had been previously isolated in this particular farm. Environmental conditions were recorded through a portable device every 5 min and then summarized using descriptive statistics. The association between HI titres and environmental microconditions, in the nursery, was evaluated through random effect linear and logistic regression. The results showed that the prevalence for H1N1_P was high throughout the study (≥70%); however, for H3N2_D, the seroprevalence declined by the end of the study period. Results also showed an association between cumulative exposure to the viruses and temperature and relative humidity (p < .05). These results suggest that microclimate conditions can influence transmission patterns of influenza viruses in swine barns, and that even a herd with relatively simple demographics could have persistent and cocirculation of two different influenza A viruses IAV strains.

Detection of Bovine Coronavirus in Healthy and Diarrheic Dairy Calves.

BACKGROUND: BCoV is identified in both healthy and diarrheic calves, complicating its assessment as a primary pathogen. OBJECTIVES: To investigate the detection rates of bovine coronavirus (BCoV) in feces of healthy and diarrheic calves and to describe the usefulness of a pancoronavirus reverse transcriptase (RT) PCR (PanCoV-RT-PCR) assay to identify BCoV in samples of diarrheic calves. ANIMALS: Two hundred and eighty-six calves <21 days. Calves with liquid or semiliquid feces, temperature >39.5°C, and inappetence were considered as cases, and those that had pasty or firm feces and normal physical examination were designated as controls. METHODS: Prospective case-control study. A specific BCoV-RT-PCR assay was used to detect BCoV in fecal samples. Association between BCoV and health status was evaluated by exact and random effect logistic regression. Fecal (n = 28) and nasal (n = 8) samples from diarrheic calves were tested for the presence of BCoV by both the PanCoV-RT-PCR and a specific BCoV-RT-PCR assays. A Kappa coefficient test was used to assess the level of agreement of both assays. RESULTS: BCoV was detected in 55% (157/286) of calves; 46% (66/143), and 64% (91/143) of healthy and diarrheic calves, respectively. Diarrheic calves had higher odds of BCoV presence than healthy calves (OR: 2.16, 95% CI: 1.26 to 3.83, P = 0.004). A good agreement between PanCoV-RT-PCR and BCoV-RT-PCR to detect BCoV was identified (κ = 0.68, 95% CI: 0.392 to 0.967; P < 0.001). CONCLUSIONS AND CLINICAL IMPORTANCE: BCoV was more likely to be detected in diarrheic than healthy calves. The PanCoV-RT-PCR assay can be a useful tool to detect CoV samples from diarrheic calves.

Development of a stochastic agent-based model to evaluate surveillance strategies for detection of emergent porcine reproductive and respiratory syndrome strains.

BACKGROUND: The objective of the current study was to develop a stochastic agent-based model using empirical data from Ontario (Canada) swine sites in order to evaluate different surveillance strategies for detection of emerging porcine reproductive and respiratory syndrome virus (PRRSV) strains at the regional level. Four strategies were evaluated, including (i) random sampling of fixed numbers of swine sites monthly; (ii) risk-based sampling of fixed numbers, specifically of breeding sites (high-consequence sites); (iii) risk-based sampling of fixed numbers of low biosecurity sites (high-risk); and (iv) risk-based sampling of breeding sites that are characterized as low biosecurity sites (high-risk/high-consequence). The model simulated transmission of a hypothetical emerging PRRSV strain between swine sites through three important industry networks (production system, truck and feed networks) while considering sites' underlying immunity due to past or recent exposure to heterologous PRRSV strains, as well as demographic, geographic and biosecurity-related PRRS risk factors. Outcomes of interest included surveillance system sensitivity and time to detection of the three first cases over a period of approximately three years. RESULTS: Surveillance system sensitivities were low and time to detection of three first cases was long across all examined scenarios. CONCLUSION: Traditional modes of implementing high-risk and high-consequence risk-based surveillance based on site's static characteristics do not appear to substantially improve surveillance system sensitivity. Novel strategies need to be developed and considered for rapid detection of this and other emerging swine infectious diseases. None of the four strategies compared herein appeared optimal for early detection of an emerging PPRSV strain at the regional level considering model assumptions, the underlying population of interest, and absence of other forms of surveillance.

Investigation of the Occurrence of Porcine Reproductive and Respiratory Virus in Swine Herds Participating in an Area Regional Control and Elimination Project in Ontario, Canada.

The main goal of this study was to investigate the occurrence of porcine reproductive and respiratory syndrome virus (PRRSV)-specific genotypes in swine sites in Ontario (Canada) using molecular, spatial and network data from a porcine reproductive and respiratory syndrome (PRRS) regional control project. For each site, location, animal movement service provider (truck companies), PRRSV status and sequencing data of the open reading frame 5 (ORF5) were obtained. Three-kilometre buffers were created to evaluate neighbourhood characteristics for each site. Social network analysis was conducted on swine sites and trucking companies to assemble the network and define network components. Three different PRRSV genotypes were used as outcomes for statistical analysis based on the region's phylogenetic tree of the ORF5. Multivariable exact logistic regression was conducted to investigate the association between being positive for a specific genotype and two main exposures of interest: (i) having at least one neighbour within three km also positive for the same genotype outside the production system and (ii) having at least one positive site for the same genotype in the same truck network component outside the production system. Results showed that the importance of area spread and truck network on PRRSV occurrence differed according to genotype. Additionally, the Ontario PRRS database appears suitable for conducting regional disease investigations. Finally, the use of relatively new tools available for network, spatial and molecular analysis could be useful in investigation, control and prevention of endemic infectious diseases in animal populations.

Identification of effective treatment criteria for use in targeted selective treatment programs to control haemonchosis in periparturient ewes in Ontario, Canada.

Haemonchosis is often associated with late gestation and parturition in ewes in Canada. Due to widespread concerns about development of anthelmintic resistance (AR), targeted selective treatment (TST), where individual animals are treated with an anthelmintic rather than the entire flock, is a possible strategy to control clinical signs in recently lambed ewes while still maintaining parasite refugia. Performing fecal egg counts (FEC) on individual animals is often cost-prohibitive, so indicators that identify ewes with high FEC are essential for TST programs. The study objectives were to: a) evaluate the ability of four TST indicators to identify periparturient ewes with high Haemonchus sp. FEC and b) determine appropriate treatment thresholds for statistically-significant indicators. A field study was conducted during the 2013 and 2014 lambing seasons (February-May) on three client-owned farms in Ontario with documented AR and problems with haemonchosis in ewes. Ewes were examined within three days of lambing and selected for treatment with oral closantel (10mg/kg body weight), a novel anthelmintic to Canada, if they met at least one of four criteria: a) the last grazing season was their first grazing season; b) body condition score ≤2; c) Faffa Malan Chart (FAMACHA©) score ≥3; and/or d) three or more nursing lambs. Fecal samples were collected per rectum on the treatment day from each of 20 randomly selected treated and untreated ewes on each farm. Haemonchus sp. percentages on each farm, as determined by coproculture, ranged from 53% to 92% of total fecal trichostrongyle-type egg counts. Mean Haemonchus sp. FECs were significantly higher in treated ewes (n=136) than in untreated ewes (n=103) on the day of treatment in both years (p=0.001), suggesting the indicators were suitable for identifying animals with high Haemonchus sp. FEC. A linear mixed model was fit with logarithmic-transformed Haemonchus sp. FEC as the outcome variable, the four indicators and year as fixed effects, and farm as a random effect. FAMACHA© score was the sole indicator to remain significantly associated with FEC (p=0.002). A receiver-operator curve determined that test sensitivity was maximized (92.4%) with FAMACHA© score ≥3 as the sole indicator. FAMACHA© score should therefore be included in TST programs to identify ewes requiring treatment at lambing due to Haemonchus sp.

Efficacy of closantel against ivermectin- and fenbendazole-resistant Haemonchus sp. in sheep in Ontario, Canada.

In Ontario, Canada, widespread resistance to ivermectin and fenbendazole, the only readily available ovine anthelmintics, has been documented, primarily in Haemonchus sp. In other parts of the world, closantel has been used to control such infections; however, the drug was not currently licensed for use in Canada and the USA. A randomized controlled trial was conducted on six client-owned farms in Ontario in 2013 and 2014 to determine the efficacy of closantel (Flukiver® 5% Oral Suspension, Elanco Animal Health, 10mg/kg bodyweight) against ivermectin- and fenbendazole-resistant Haemonchus sp. infections in periparturient ewes and grazing lambs. Three farms were randomly assigned to treat all ewes, and three farms were randomly assigned to selectively treat individual ewes at lambing, using predetermined criteria. Fecal samples were collected from a minimum of 15 randomly selected ewes and 13 lambs per group on each farm at the time of treatment and approximately 14days later. Trichostrongyle-type fecal egg counts (FEC) were performed using a modified McMaster technique with a lower detection limit of 8.3 eggs per gram of feces (epg). Haemonchus-specific FECs were determined by multiplying FECs by the proportion of Haemonchus sp. identified from coproculture for each farm; Haemonchus-specific FEC reductions were calculated for each farm. Twenty grazing lambs had FECs conducted monthly, and when mean monthly FECs surpassed 200 epg, all lambs were randomly allocated to either closantel, positive control (ivermectin, fenbendazole, or levamisole) or negative control groups. Pre-treatment Haemonchus-specific mean FECs ranged from 27 to 3359 epg in ewes and 0-5698 epg in lambs. Efficacy of closantel against Haemonchus sp. ranged from 99% (95% CI: 97%-99%) to 100% in recently lambed ewes on all farms in both years (total n=274 ewes), and from 99% (95% CI: 98%-99%) to 100% in grazing lambs in both years on all but one farm (total n=171 lambs). On the latter farm, a whole flock treated farm, closantel efficacy in grazing lambs was 84% (95%CI: 81%-88%) in the first year, but 100% in the second year. Levamisole was effective against overall GIN in lambs on only two farms. Ivermectin and fenbendazole resistance continued to be present, particularly in Haemonchus sp. Closantel had excellent efficacy against Haemonchus sp. over the two year study period, regardless of treatment group, and therefore should be considered one viable component of sustainable integrated parasite control programs for farms with documented anthelmintic resistance and problems with haemonchosis.

Network, cluster and risk factor analyses for porcine reproductive and respiratory syndrome using data from swine sites participating in a disease control program.

The objectives of this study were to describe networks of Ontario swine sites and their service providers (including trucking, feed, semen, gilt and boar companies); to categorize swine sites into clusters based on site-level centrality measures, and to investigate risk factors for porcine reproductive and respiratory syndrome (PRRS) using information gathered from the above-mentioned analyses. All 816 sites included in the current study were enrolled in the PRRS area regional control and elimination projects in Ontario. Demographics, biosecurity and network data were collected using a standardized questionnaire and PRRS status was determined on the basis of available diagnostic tests and assessment by site veterinarians. Two-mode networks were transformed into one-mode dichotomized networks. Cluster and risk factor analyses were conducted separately for breeding and growing pig sites. In addition to the clusters obtained from cluster analyses, other explanatory variables of interest included: production type, type of animal flow, use of a shower facility, and number of neighboring swine sites within 3km. Unadjusted univariable analyses were followed by two types of adjusted models (adjusted for production systems): a generalizing estimation equation model (GEE) and a generalized linear mixed model (GLMM). Results showed that the gilt network was the most fragmented network, followed by the boar and truck networks. Considering all networks simultaneously, approximately 94% of all swine sites were indirectly connected. Unadjusted risk factor analyses showed significant associations between almost all predictors of interest and PRRS positivity, but these disappeared once production system was taken into consideration. Finally, the vast majority of the variation on PRRS status was explained by production system according to GLMM, which shows the highly correlated nature of the data, and raises the point that interventions at this level could potentially have high impact in PRRS status change and/or maintenance.

One-Health Simulation Modelling: Assessment of Control Strategies Against the Spread of Influenza between Swine and Human Populations Using NAADSM.

Simulation models implemented using a range of parameters offer a useful approach to identifying effective disease intervention strategies. The objective of this study was to investigate the effects of key control strategies to mitigate the simultaneous spread of influenza among and between swine and human populations. We used the pandemic H1N1 2009 virus as a case study. The study population included swine herds (488 herds) and households-of-people (29,707 households) within a county in Ontario, Canada. Households were categorized as: (i) rural households with swine workers, (ii) rural households without swine workers and (iii) urban households without swine workers. Seventy-two scenarios were investigated based on a combination of the parameters of speed of detection and control strategies, such as quarantine strategy, effectiveness of movement restriction and ring vaccination strategy, all assessed at three levels of transmissibility of the virus at the swine-human interface. Results showed that the speed of detection of the infected units combined with the quarantine strategy had the largest impact on the duration and size of outbreaks. A combination of fast to moderate speed of the detection (where infected units were detected within 5-10 days since first infection) and quarantine of the detected units alone contained the outbreak within the swine population in most of the simulated outbreaks. Ring vaccination had no added beneficial effect. In conclusion, our study suggests that the early detection (and therefore effective surveillance) and effective quarantine had the largest impact in the control of the influenza spread, consistent with earlier studies. To our knowledge, no study had previously assessed the impact of the combination of different intervention strategies involving the simultaneous spread of influenza between swine and human populations.

Analysis of Swine Movement in Four Canadian Regions: Network Structure and Implications for Disease Spread.

Direct and indirect contacts among animal holdings are important in the spread of infectious diseases. The objectives of this study were to describe networks of pig movements and the sharing of trucks used for those movements between swine farms in four Canadian regions using network analysis tools and to obtain contact parameters for infectious disease spread simulation models. Four months of swine movement data from a pilot pig traceability programme were used. Two types of networks were created using three time scales (weekly, monthly and the full study period): one-mode networks of farm-to-farm direct contact representing animal shipments and two-mode networks representing the sharing of trucks between farms. Contact patterns among farms were described by estimating a range of relevant network measures. The overall network neglecting the four regions consisted of 145 farms, which were connected by 261 distinct links. A total of 184 trucks were used to transport 2043 shipments of pigs during the study period. The median in- and out-degree for the overall one-mode network was 1 and ranged from 0 to 26 and 0 to 10, respectively. The overall one-mode network had heterogeneous degree distribution, a high clustering coefficient and shorter average path length than would be expected for randomly generated networks of similar size. On average one truck was shared by four farms in the overall network, or by three farms when considered the monthly and weekly networks. Degree distribution of the two-mode overall network demonstrated characteristics of power-law distribution. For more than 50% of shipments on any given day, the same truck was used for at least one other shipment. Findings from this study are in agreement with previous work, which suggested that swine movement networks exhibit small-world and scale-free topologies. Furthermore, trucks used for the shipment of pigs can play an important role in connecting otherwise unconnected farms and may increase the spread of disease.

Association Between PRRSV ORF5 Genetic Distance and Differences in Space, Time, Ownership and Animal Sources Among Commercial Pig Herds.

The objective of this study was to investigate associations between genetic distance of porcine reproductive and respiratory syndrome virus (PRRSV) detected in Ontario swine herds, and the distance between the herds with respect to space, time, ownership and animal sources. PRRSV sequence data between September 2004 and August 2007 were obtained from the Animal Health Laboratory of the University of Guelph. Geographical coordinates were obtained from the Ontario Pork marketing board, and network information about ownership and animal suppliers was obtained using a telephone interview. The matrices of sequence, spatial, temporal and network distances were generated and were analysed using the Mantel test, and using linear-mixed models with P-values based on random permutations. A total of 438 PRRSV isolates from 329 premises and 232 ownerships were originally included; 57 of the isolates were considered vaccine type. The Mantel correlation test indicated that there was positive correlation between sequence distance and geographic distance (r = 0.11, P = 0.001), as well as sequence distance and temporal distance (r = 0.03, P = 0.03), with similar results reported after adjusting for the ownership distance. Mantel correlogram suggested existence of spatial correlation up to ~30 km distance. Multivariable linear-mixed model for association between genetic distance and space-time distance was characterized by the three-way interaction among space, time and ownership (P < 0.001). It suggested that positive association between sequence similarity and spatial proximity exists in herds under different ownerships, but its magnitude is very small. In contrast, for pairs of herds under identical ownership, the spatial association was more complex. This could be a consequence of interactions within ownerships, or alternatively decisions made about sampling of herds for diagnostic purposes. Of the networks evaluated, ownership (P < 0.001) and gilt supplier (P < 0.001) showed the highest magnitude of association with genetic distance and should be investigated further for their impact on disease spread.

One-Health Simulation Modelling: A Case Study of Influenza Spread between Human and Swine Populations using NAADSM.

The circulation of zoonotic influenza A viruses including pH1N1 2009 and H5N1 continue to present a constant threat to animal and human populations. Recently, an H3N2 variant spread from pigs to humans and between humans in limited numbers. Accordingly, this research investigated a range of scenarios of the transmission dynamics of pH1N1 2009 virus at the swine-human interface while accounting for different percentages of swine workers initially immune. Furthermore, the feasibility of using NAADSM (North American Animal Disease Spread Model) applied as a one-health simulation model was assessed. The study population included 488 swine herds and 29, 707 households of people within a county in Ontario, Canada. Households were categorized as follows: (i) rural households with swine workers, (ii) rural households without swine workers, and (iii) urban households without swine workers. Forty-eight scenarios were investigated, based on the combination of six scenarios around the transmissibility of the virus at the interface and four vaccination coverage levels of swine workers (0-60%), all under two settings of either swine or human origin of the virus. Outcomes were assessed in terms of stochastic 'die-out' fraction, size and time to peak epidemic day, overall size and duration of the outbreaks. The modelled outcomes indicated that minimizing influenza transmissibility at the interface and targeted vaccination of swine workers had significant beneficial effects. Our results indicate that NAADSM can be used as a framework to model the spread and control of contagious zoonotic diseases among animal and human populations, under certain simplifying assumptions. Further evaluation of the model is required. In addition to these specific findings, this study serves as a benchmark that can provide useful input to a future one-health influenza modelling studies. Some pertinent information gaps were also identified. Enhanced surveillance and the collection of high-quality information for more accurate parameterization of such models are encouraged.

Androgen deprivation therapy and cardiovascular complications.

Cardiovascular complications associated with the use of antiandrogens have already been known for some time. Based on the results of the latest meta-analyses and clinical studies published in the last few years, the attention of the scientific community is focused on the deleterious cardiovascular effects of gonadotropine-releasing hormon agonists in context of the androgen deprivating therapy. The cardiac toxicity is a problem especially in patients with preexisting cardiovascular comorbidities. Increased arterial wall thickening along with endothelial dysfunction has been observed in patients with descreased androgens levels in the peripheral blood. The treatment with gonadotropine-releasing hormon agonists may disrupt the intracellular concentration of calcium ions and the contractile process and potentially result in pathological remodelling of heart. Here, we give several possible mechanisms of action of gonadotropine-releasing hormon agonists on the cardiovascular system that may be a potential explanation of the clinical observations (Ref. 44).

An evaluation of rabies vaccination rates among canines and felines involved in biting incidents within the Wellington-Dufferin-Guelph Public Health Department.

The objectives of this study were to determine the rate of animal bite incidents occurring in the human population of a local health department, and to determine the proportion of these canines and felines that were not up to date on their rabies vaccination at the time the incident occurred. Data were obtained from animal bite incidents reported to Wellington-Dufferin-Guelph Public Health during 2010 and 2011. Descriptive statistics of 718 eligible reports revealed the average rate of animal biting was 1.55 bites per 1000 residents per year. Approximately 54% of these animals were vaccinated against rabies, 32% were not up to date with their rabies vaccination, and the remaining 14.5% were of unknown status. The unit of analysis was the municipality, and the four outcomes of interest were: (i) number of animal bite incidents per 1000 residents, (ii) number of dog bite incidents per 1000 residents, (iii) proportion of animals involved in bite incidents that were not up to date with their rabies vaccination, and (iv) proportion of dogs that were not up to date. Associations between the outcomes and selected demographic variables were investigated using regression analysis. The number of veterinary clinics per 10,000 residents, and whether the municipality was urban or rural were identified as significant predictors for the number of animal bites per 1000 residents, and the number of dog bites. There were no significant predictors for the proportion of unvaccinated animals or dogs. Spatial clustering and the location of spatial clusters were assessed using the empirical Bayes index and spatial scan test. This analysis identified five municipalities within the health department that have a high rate of biting incidents and a high proportion of animals that were not up to date on their rabies vaccination. Such municipalities are ideal for targeted educational campaigns regarding the importance of vaccination in pets.

The effectiveness of Coxiella burnetii vaccines in occupationally exposed populations: a systematic review and meta-analysis.

To estimate the effect of vaccination in preventing acute Q fever in individuals occupationally exposed to Coxiella burnetii, a systematic review and meta-analysis were undertaken in controlled trials and observational studies. Publications were obtained through a scoping study of English and non-English articles, and those reporting a commercially licensed or licensable vaccine compared with an unvaccinated or placebo control group were included in the review. Two authors performed independent assessment of risk of systematic error and data extraction. One controlled trial and five cohort publications met the inclusion criteria. All trials used a Henzerling phase I vaccine. A random-effects meta-analysis estimated significant protection in abattoir workers (RR = 0.07; 95% confidence interval [CI] 0.02-0.22) compared with the control individuals. In individuals with rare or sporadic contact with the abattoir, a significant benefit of vaccination was also found (RR = 0.06; 95% CI 0-0.93). Overall, the vaccine effectively prevented acute Q fever in individuals responsible for handling animals or their products and those working in the abattoir but not directly exposed to animals (RR = 0.06; 95% CI 0.02-0.18). Caution must be taken when interpreting the effect of C. burnetii vaccination as significant heterogeneity amongst publications was observed. A meta-regression found no significant univariate associations. This may reflect the uncertainty provided by reported data in the cohort publications. Potential systematic biases were present in the publications, and evidence included may not be sufficiently robust to extrapolate the effect of vaccination on occupationally exposed groups beyond the population of abattoir employees in Australia where all included studies occurred.

A systematic review and meta-analysis of phase I inactivated vaccines to reduce shedding of Coxiella burnetii from sheep and goats from routes of public health importance.

Q fever in humans and coxiellosis in livestock are both caused by Coxiella burnetii. The public health importance of vaccination against C. burnetii shedding from sheep and goats was evaluated using systematic review and meta-analysis to provide evidence for policy direction to prevent potential zoonotic spread. Publications reporting shedding of C. burnetii in vaginal and uterine secretions, milk, placenta and faeces were included. A single observational (one goat) and seven experimental (four goat and three sheep) vaccine studies were included in the review. No relevant publications on other interventions were identified. Random effects meta-analyses were performed for the risk of shedding in individuals in the control and vaccinated groups and for the mean difference in the level of bacterial shedding in sheep and goats stratified by age and previous exposure status. Limited data were available for further analytic evaluation. From the pooled analysis, an inactivated phase I vaccine significantly reduced the risk of shedding from uterine (RR = 0.10; 95%CI 0.05-0.20) secretions in previously sensitized goats. Individual studies reported significant risk reduction in milk (RR = 0.03; 95%CI 0.01-0.26), vaginal secretions (RR = 0.40; 95%CI 0.22-0.75) and faeces (RR = 0.79; 95%CI 0.63-0.97) from naïve goats. The pooled mean levels of bacteria shed from placental [mean difference (MD = -5.24 Log10 ; 95%CI -6.75 to -3.7)] and vaginal (MD = -1.78 Log10 ; 95%CI -2.19 to -1.38) routes were significantly decreased in vaccinated naïve goats compared with controls. Shedding through all other routes from vaccinated goats was not significantly different than shedding from control goats. No effect of vaccination was found on the risk of shedding or the mean level of shedding in vaccinated sheep compared with control sheep. Our conclusions are based on a limited amount of data with variable risk of systematic error.

Network analysis of swine shipments in Ontario, Canada, to support disease spread modelling and risk-based disease management.

Understanding contact networks are important for modelling and managing the spread and control of communicable diseases in populations. This study characterizes the swine shipment network of a multi-site production system in southwestern Ontario, Canada. Data were extracted from a company's database listing swine shipments among 251 swine farms, including 20 sow, 69 nursery and 162 finishing farms, for the 2-year period of 2006 to 2007. Several network metrics were generated. The number of shipments per week between pairs of farms ranged from 1 to 6. The medians (and ranges) of out-degree were: sow 6 (1-21), nursery 8 (0-25), and finishing 0 (0-4), over the entire 2-year study period. Corresponding estimates for in-degree of nursery and finishing farms were 3 (0-9) and 3 (0-12) respectively. Outgoing and incoming infection chains (OIC and IIC), were also measured. The medians (ranges) of the monthly OIC and IIC were 0 (0-8) and 0 (0-6), respectively, with very similar measures observed for 2-week intervals. Nursery farms exhibited high measures of centrality. This indicates that they pose greater risks of disease spread in the network. Therefore, they should be given a high priority for disease prevention and control measures affecting all age groups alike. The network demonstrated scale-free and small-world topologies as observed in other livestock shipment studies. This heterogeneity in contacts among farm types and network topologies should be incorporated in simulation models to improve their validity. In conclusion, this study provided useful epidemiological information and parameters for the control and modelling of disease spread among swine farms, for the first time from Ontario, Canada.

A review of simulation modelling approaches used for the spread of zoonotic influenza viruses in animal and human populations.

Increasing incidences of emerging and re-emerging diseases that are mostly zoonotic (e.g. severe acute respiratory syndrome, avian influenza H5N1, pandemic influenza) has led to the need for a multidisciplinary approach to tackling these threats to public and animal health. Accordingly, a global movement of 'One-Health/One-Medicine' has been launched to foster collaborative efforts amongst animal and human health officials and researchers to address these problems. Historical evidence points to the fact that pandemics caused by influenza A viruses remain a major zoonotic threat to mankind. Recently, a range of mathematical and computer simulation modelling methods and tools have increasingly been applied to improve our understanding of disease transmission dynamics, contingency planning and to support policy decisions on disease outbreak management. This review provides an overview of methods, approaches and software used for modelling the spread of zoonotic influenza viruses in animals and humans, particularly those related to the animal-human interface. Modelling parameters used in these studies are summarized to provide references for future work. This review highlights the limited application of modelling research to influenza in animals and at the animal-human interface, in marked contrast to the large volume of its research in human populations. Although swine are widely recognized as a potential host for generating novel influenza viruses, and that some of these viruses, including pandemic influenza A/H1N1 2009, have been shown to be readily transmissible between humans and swine, only one study was found related to the modelling of influenza spread at the swine-human interface. Significant gaps in the knowledge of frequency of novel viral strains evolution in pigs, farm-level natural history of influenza infection, incidences of influenza transmission between farms and between swine and humans are clearly evident. Therefore, there is a need to direct additional research to the study of influenza transmission dynamics in animals and at the animal-human interface.