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Regional distribution of non-human H7N9 avian influenza virus detections in China and construction of a predictive model
2021
Huang, Zeying | Li, Haijun | Huang, Beixun
H7N9 avian influenza has broken out in Chinese poultry 10 times since 2013 and impacted the industry severely. Although the epidemic is currently under control, there is still a latent threat. Epidemiological surveillance data for non-human H7N9 avian influenza from April 2013 to April 2020 were used to analyse the regional distribution and spatial correlations of positivity rates in different months and years and before and after comprehensive immunisation. In addition, positivity rate monitoring data were disaggregated into a low-frequency and a high-frequency trend sequence by wavelet packet decomposition (WPD). The particle swarm optimisation algorithm was adopted to optimise the least squares support-vector machine (LS-SVM) model parameters to predict the low-frequency trend sequence, and the autoregressive integrated moving average (ARIMA) model was used to predict the high-frequency one. Ultimately, an LS-SVM-ARIMA combined model based on WPD was constructed. The virus positivity rate was the highest in late spring and early summer, and overall it fell significantly after comprehensive immunisation. Except for the year 2015 and the single month of December from 2013 to 2020, there was no significant spatiotemporal clustering in cumulative non-human H7N9 avian influenza virus detections. Compared with the ARIMA and LS-SVM models, the LS-SVM-ARIMA combined model based on WPD had the highest prediction accuracy. The mean absolute and root mean square errors were 2.4% and 2.0%, respectively. Low error measures prove the validity of this new prediction method and the combined model could be used for inference of future H7N9 avian influenza virus cases. Live poultry markets should be closed in late spring and early summer, and comprehensive H7N9 immunisation continued.
Afficher plus [+] Moins [-]Porcine enteric coronavirus infections in wild boar in Poland – a pilot study
2021
Antas, Marta | Olech, Monika | Szczotka-Bochniarz, Anna
Porcine epidemic diarrhoea virus (PEDV) of the Coronaviridae family causes significant economic losses in the pig industry worldwide. Wild boars contribute to the transmission of different viral, bacterial and parasitic infections to livestock animals and humans. However, their role in the maintenance and transmission of PEDV has not been established. In this study, blood and faecal samples from 157 wild boars were collected from 14 provinces of Poland during the 2017–2018 hunting season. RNA was extracted from the faecal homogenate supernatant and subjected to quantitative RT-PCR (RT-qPCR), while clotted blood samples were used for detection of antibodies against PEDV by ELISA. Five blood samples (3.2%) were seropositive in ELISA, while none of the faecal samples were found positive using RT-qPCR assays. The results of this analysis indicate the need for additional studies incorporating a larger number of samples and preferably comparing different serological methods, to confirm whether wild boars in Poland act as PEDV reservoirs.
Afficher plus [+] Moins [-]The main DNA viruses significantly affecting pig livestock
2020
Swine DNA viruses have developed unique mechanisms for evasion of the host immune system, infection and DNA replication, and finally, construction and release of new viral particles. This article reviews four classes of DNA viruses affecting swine: porcine circoviruses, African swine fever virus, porcine parvoviruses, and pseudorabies virus. Porcine circoviruses belonging to the Circoviridae family are small single-stranded DNA viruses causing different diseases in swine including poly-weaning multisystemic wasting syndrome, porcine dermatitis and nephropathy syndrome, and porcine respiratory disease complex. African swine fever virus, the only member of the Asfivirus genus in the Asfarviridae family, is a large double-stranded DNA virus and for its propensity to cause high mortality, it is currently considered the most dangerous virus in the pig industry. Porcine parvoviruses are small single-stranded DNA viruses belonging to the Parvoviridae family that cause reproductive failure in pregnant gilts. Pseudorabies virus, or suid herpesvirus 1, is a large double-stranded DNA virus belonging to the Herpesviridae family and Alphaherpesvirinae subfamily. Recent findings including general as well as genetic classification, virus structure, clinical syndromes and the host immune system responses and vaccine protection are described for all four swine DNA virus classes.
Afficher plus [+] Moins [-]Current status of porcine epidemic diarrhoea (PED) in European pigs
2019
Porcine epidemic diarrhoea (PED) is a highly contagious and devastating enteric disease of pigs caused by porcine epidemic diarrhoea virus (PEDV), an enveloped, single-stranded RNA virus belonging to the Alphacoronavirus genus of the Coronaviridae family. The disease is clinically similar to other forms of porcine gastroenteritis. Pigs are the only known host of the disease, and the occurrence of PED in wild boars is unknown. The virus causes acute diarrhoea, vomiting, dehydration, and high mortality in suckling piglets reaching 100%. Heavy economic losses in the pig-farming industry were sustained in the USA between 2013 and 2015 when PEDV spread very quickly and resulted in epidemics. The loss in the US pig industry has been estimated at almost seven million pigs. The purpose of this review is a description of the current status of porcine epidemic diarrhoea in European pigs and the risk presented by the introduction of PEDV to Poland in comparison to the epidemics in the USA.
Afficher plus [+] Moins [-]Advances in research on genetic relationships of waterfowl parvoviruses
2021
Chen, Yanhui | Afumba, Ruth | Pang, Fusheng | Yuan, Rongxin | Dong, Hao
Derzsy’s disease and Muscovy duck parvovirus disease have become common diseases in waterfowl culture in the world and their potential to cause harm has risen. The causative agents are goose parvovirus (GPV) and Muscovy duck parvovirus (MDPV), which can provoke similar clinical symptoms and high mortality and morbidity rates. In recent years, duck short beak and dwarfism syndrome has been prevalent in the Cherry Valley duck population in eastern China. It is characterised by the physical signs for which it is named. Although the mortality rate is low, it causes stunting and weight loss, which have caused serious economic losses to the waterfowl industry. The virus that causes this disease was named novel goose parvovirus (NGPV). This article summarises the latest research on the genetic relationships of the three parvoviruses, and reviews the aetiology, epidemiology, and necropsy characteristics in infected ducks, in order to facilitate further study.
Afficher plus [+] Moins [-]Cell viability in normal fibroblasts and liver cancer cells after treatment with iron (III), nickel (II), and their mixture
2018
Terpiłowska, Sylwia | Siwicka-Gieroba, Dorota | Siwicki, Andrzej Krzysztof
Introduction: Nickel and iron are very commonly occurring metals. Nickel is used in industry, but nowadays it is also used in medical biomaterials. Iron is an element necessary for cell metabolism and is used in diet supplements and biomaterials, whence it may be released along with nickel. Material and Methods: BALB/3T3 and HepG2 cells were incubated with iron chloride or nickel chloride at concentrations ranging from 100 to 1,400 µM. The following mixtures were used: iron chloride 200 µM plus nickel chloride 1,000 µM, or iron chloride 1,000 µM plus nickel chloride 200 µM. The cell viability was determined with MTT, LHD, and NRU tests. Results: A decrease in cell viability was observed after incubating the BALB/3T3 and HepG2 cells with iron chloride or nickel chloride. A synergistic effect was observed after iron chloride 1,000 μM plus nickel chloride 200 μM treatment in all assays. Moreover, the same effect was observed in the pair iron chloride 200 μM plus nickel chloride 1,000 μM in the LDH and NRU assays. Conclusions: Iron (III) and nickel (II) decrease cell viability. Iron chloride at a concentration of 200 µM protects mitochondria from nickel chloride toxicity.
Afficher plus [+] Moins [-]Efficacy of natural formulations in bovine mastitis pathology: alternative solution to antibiotic treatment
2020
Pașca, Claudia | Mărghitaș, Liviu Alexandru | Dezmirean, Daniel Severus | Matei, Ioana Adriana | Bonta, Victorița | Pașca, Ioan | Chirilă, Flore | Cîmpean, Adrian | Iosif Fiț, Nicodim
Bovine mastitis is an inflammatory disease of the udder that causes important economic losses in the animal breeding and dairy product industries. Nowadays, the conventional livestock antibiotic treatments are slowly being replaced by alternative treatments. In this context, the main aim of this study was to evaluate the efficacy of natural products in alternative treatment of bovine mastitis. Two natural formulations with previously suggested in vitro antimicrobial effect were tested in vivo on mastitic cows. Animals with a positive diagnosis for mastitis (n = 20) were divided into three treatment groups: two groups (n = 8) were administered formulations of propolis, alcoholic extracts of Brewers Gold and Perle hops, plum lichen, common mallow, marigold, absinthe wormwood, black poplar buds, lemon balm, and essential oils of oregano, lavender, and rosemary designated R4 and R7 (differing only in the latter being more concentrated) and one group (n = 4) a conventional antibiotic mixture. In vivo efficacy of treatments was evaluated by somatic cell and standard plate counts, the treatment being considered efficacious when both parameters were under the maximum limit. R7 was effective in the most cases, being therapeutically bactericidal in six out of eight cows, while R4 gave good results in three out of eight cows, and conventional antibiotics cured one out of four. These results suggest the possible therapeutic potential of these natural products in bovine mastitis.
Afficher plus [+] Moins [-]Descriptive analysis and spatial epidemiology of porcine reproductive and respiratory syndrome (PRRS) for swine sites participating in area regional control and elimination programs from 3 regions of Ontario
2015
Arruda, Andreia G. | Poljak, Zvonimir | Friendship, Robert | Carpenter, Jane | Hand, Karen
The objectives of this study were to describe demographics, basic biosecurity practices, ownership structure, and prevalence of porcine reproductive and respiratory syndrome (PRRS) in swine sites located in 3 regions in Ontario, and investigate the presence of spatial clustering and clusters of PRRS positive sites in the 3 regions. A total of 370 swine sites were enrolled in Area Regional Control and Elimination projects in Niagara, Watford, and Perth from 2010 to 2013. Demographics, biosecurity, and site ownership data were collected using a standardized questionnaire and site locations were obtained from an industry organization. Status was assigned on the basis of available diagnostic tests and/or assessment by site veterinarians. Spatial dependence was investigated using the D-function, the spatial scan statistic test and the spatial relative risk method. Results showed that the use of strict all-in all-out (AIAO) pig flow and shower before entry are uncommon biosecurity practices in swine sites, but a larger proportion of sites reported having a Danish entry. The prevalence of PRRS in the 3 regions ranged from 17% to 48% and localized high and low risk clusters were detected. Sites enrolled in the PRRS control projects were characterized by membership in multiple and overlapping ownership structures and networks, which complicates the way the results of monitoring and disease management measures are communicated to the target population.
Afficher plus [+] Moins [-]Rates and determinants of antimicrobial use, including extra-label, on Ontario sheep farms
2011
Moon, Catherine S. | Berke, Olaf | Avery, Brent P. | McEwen, Scott A. | Reid-Smith, Richard J. | Scott, Lisa | Menzies, Paula
Few antimicrobials are licensed for use in sheep in Canada, and the range of indications is narrow. Treatment in an “extra-label” manner may be ineffective. In addition, potentially harmful drug residues in food-animal products and antimicrobial resistance in bacteria may be associated with extra-label drug use (ELDU). No data had been documented on drug use, specifically antimicrobial use (AMU), in Ontario sheep, although it was thought that much use was extra-label. This study investigated AMU and ELDU on 49 lamb-producing Ontario sheep farms. Data were prospectively collected over 12 months from the participating farms, and farm-level practices were ascertained with a questionnaire. Treatment-level and farm-level variables were investigated for associations with rates of AMU by means of Poisson rate regression models fit with a generalized estimating equation to control for clustering at the farm level. Antimicrobials with high mean exposure rates included chlortetracycline (in feed), penicillins, and oxytetracycline. The exposure rate in lambs was significantly lower (P < 0.01) with antimicrobial treatment of systemic signs, respiratory disease, or wound or injury than with treatment of other reported diseases or conditions; it was also significantly lower with 3 or more lambing periods per year (α = 0.05). The exposure rate in adult sheep was significantly lower with treatment of 5 of the 6 most prevalent diseases or conditions (α = 0.05) and significantly higher with producer decision to treat and producer experience of 20 y or greater. Rates of using antimicrobials not licensed for use in sheep were high, as was extra-label use of licensed antimicrobials. Diseases reportedly treated most often with antimicrobials (e.g., systemic signs, mastitis) were significantly associated with lower rates of ELDU (α = 0.05). Compared with the rates in adult sheep, the mean rate of use of nonlicensed antimicrobials was similar in the lambs, whereas the mean rate of extra-label use of licensed antimicrobials was lower among the lambs. The results are useful in determining if public health concerns about antimicrobial use in Ontario sheep are warranted and in creating drug use and licensure strategies for the Canadian sheep industry.
Afficher plus [+] Moins [-]Evaluation of a veterinary-based syndromic surveillance system implemented for swine
2010
Practicing veterinarians play an important role in detecting the initial outbreak of disease in animal populations. A pilot study was conducted to determine the feasibility of a veterinary-based surveillance system for the Ontario swine industry. A total of 7 practitioners from 5 clinics agreed to submit information from July 1, 2007 to June 30, 2008. The surveillance program was evaluated in terms of timeliness, compliance, geographic coverage, and data quality. Our study showed that the veterinary-based surveillance system was acceptable to practitioners and produced useful data. The program obtained information from 25% of pig farms in Ontario during this time period. However, better communication with practitioners, more user-friendly recording systems that can be adapted to each clinic’s management system, active involvement of the clinics’ technical personnel, and the use of financial incentives may help to improve compliance and timeliness.
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