National Veterinary Institute, Sweden
Recent publications
Background: An outdoor pig herd was affected by severe respiratory disease in one out of three pastures. At necropsy, Mycoplasma hyopneumoniae and Pasteurella multocida were detected in the lungs, as well as the lung worm Metastrongylus apri. The life cycle of Metastrongylus spp. includes earthworms as intermediate hosts, and since domestic pigs mainly are reared indoors, lungworm infections have not been diagnosed in domestic pigs in Sweden for decades, not even in pigs reared outdoors. Therefore, this disease outbreak was scrutinised from the view of validating the impact of Metastrongylus spp. Results: At the time of the disease outbreak, neither eggs of Metastrongylus spp., Trichuris suis nor Ascaris suum were detected in faeces of pigs aged ten weeks. In contrast, five-months-old pigs at the pasture with respiratory disease shed up to 3800 eggs per gram (Epg) of Ascaris suum and up to 1100 Epg of Trichuris suis, whereas eggs of these parasites were not demonstrated in healthy pigs aged six months at another pasture. Low numbers of eggs from Metastrongylus spp. (< 150 Epg) were seen in faecal samples from both these age categories. At slaughter, seven weeks later, ten normal weighted pigs in the preceding healthy batch were compared with ten normal weighted and five small pigs from the affected batch. Healing Mycoplasma-like pneumonic lesions were seen in all groups. All small pigs shed eggs of Ascaris suum in the faeces, compared to around 50% of the larger pigs. Metastrongylus spp. were demonstrated in 13 of the 25 pigs (52%), representing all groups included. Conclusion: As Metastrongylus spp. were demonstrated regardless of health status, and also in another healthy outdoor herd, the impact of Metastrongylus spp. on the outbreak of respiratory disease was depreciated. Instead, a possible association with a high burden of Ascaris suum was suggested to have preceded the severe outbreak with respiratory disease in the affected herd. Further, it was concluded that Metastrongylus spp. will escape detection at routine meat inspections made at slaughterhouses, and as they appeared to generally not induce clinical signs of respiratory disease Metastrongylus spp. may be more common in outdoor production than previously believed.
Background: Ascaridia galli is a widespread problem in cage-free egg production. Sustainable control of nematode infections is a key component in this sector. This study investigates the effect of a treatment strategy against A. galli, aiming to propose a guideline for anthelmintic use on commercial poultry farms. Methods: A total of eight flocks of laying hens (a-h) from five commercial poultry farms were included in this study. Faecal samples were collected on a biweekly basis starting at 7-13 weeks post-placement (WPP) and processed using the McMaster method to calculate ascarid egg shedding. Flocks were treated after the threshold of 200 eggs per gram of faeces (EPG) was reached. Results: The highest initial faecal egg count was 6700 EPG at 11 WPP, whereas the lowest was 50 at 8 WPP. The longest delay to detect A. galli was 7 weeks. The lowest and the highest number of treatments were four and six, respectively. The shortest and longest periods between any two treatments were 5 and 22 weeks, respectively. Conclusions: These results suggest that monitoring for A. galli should start at approximately 7 WPP and should be repeated every 8 weeks until hens are 50 weeks old. Treatment should be given only if moderate to high faecal egg counts are observed. Treatments after this point may be repeated every 8 weeks without eventually performing a faecal test. These findings provide practical support to veterinarians and egg producers dealing with ascarid worm infection in laying hens in their production stage.
Objectives The aim of this study was to describe the clinical picture in cats with alpha-chloralose (AC) intoxication and to confirm AC in serum from suspected cases of AC poisoning. Methods Suspected cases of AC poisoning were identified in patient records from a small animal university hospital from January 2014 to February 2020. Clinical signs of intoxication described in respective records were compiled, the cats were graded into four intoxication severity scores and hospitalisation time and mortality were recorded. Surplus serum from select cases in late 2019 and early 2020 was analysed to detect AC with a quantitative ultra-high performance liquid chromatography tandem mass spectrometry analysis, and the AC concentration was compared with the respective cat’s intoxication severity score. Results Serum from 25 cats was available for analysis and AC poisoning was confirmed in all. Additionally, 78 cats with a clinical suspicion of AC intoxication were identified in the patient records, most of which presented from September to April. The most common signs of intoxication were ataxia, tremors, cranial nerve deficits and hyperaesthesia. The prevalence of clinical signs and intoxication severity differed from what has previously been reported, with our population presenting with less severe signs and no deaths due to intoxication. The majority had a hospitalisation time <48 h, irrespective of intoxication severity score. Conclusions and relevance This study describes the clinical signs and prognosis in feline AC intoxication. There were no mortalities in confirmed cases, indicating that AC-poisoned cats have an excellent prognosis when treated in a timely manner. Recognition of AC intoxication as a differential diagnosis for acute onset of the described neurological signs in areas where AC exposure is possible may influence clinical decision-making and help avoid excessive diagnostic procedures. A severe clinical picture upon presentation could be misinterpreted as a grave prognosis and awareness about AC poisoning may avoid unnecessary euthanasia.
In Sweden, the County Administrative Board (CAB) and Swedish Trotting Association (STA) both perform animal welfare inspections of the premises of trotting horse trainers. The CAB inspection checks for compliance with the legislation, and the STA inspection checks for compliance with the private ‘Trotter Health Standard’, which mainly sets the same requirements as the legislation. This study investigated the views of trainers on these inspections both as separate events and in relation to each other. A digital questionnaire was sent out to trotting horse trainers in Sweden during spring 2021, and 396 trainers responded. Descriptive and statistical analyses were used to evaluate the responses. In general, the trainers reported positive experiences of both the CAB and STA inspections, but they had consistently more positive views about the private STA inspections than the official CAB inspections. The outcome of the inspections, i.e., non-compliance or not, did not affect trainers’ perceptions of the inspections, but inspectors’ knowledge, manner, and responsiveness had a strong effect. The trainers were generally satisfied with the current control system but would like better coordination between the different inspections.
In autumn 2019, the Public Health Agency of Sweden identified a cluster of Salmonella Newport cases by whole genome sequencing (WGS). Cases’ distribution in place and time indicated a nation-wide ongoing outbreak. An investigation was initiated to identify the source and prevent further cases. We conducted a case–case study based on notified salmonellosis cases and a Salmonella trawling questionnaire, comparing 20 outbreak cases and 139 control cases. Food exposures were compared by adjusted odds ratios (aOR) with 95% confidence interval (CI) using logistic regression. Implicated foods were sampled. Outbreak cases were more likely to have consumed crayfish (aOR = 26; 95% CI: 6.3–105). One specific brand of imported frozen, pre-cooked whole crayfish in dill brine was identified as the source. Salmonella Newport was later detected in different batches from retail and in one sample from border control. Isolates from food samples clustered with the human outbreak strain by WGS. Although the retailer made a complete recall, two more cases were identified long afterwards. This investigation demonstrated the successful use of a case–case study and targeted microbiological testing to identify the source. The immediate action taken by the retailer was important to confirm the source and stop the outbreak.
Phylogenetic evidence from the recent resurgence of high pathogenicity avian influenza (HPAI) subtype H5N1, clade, observed in European wild birds and poultry since October 2021, suggests at least two different and distinct reservoirs. We propose contrasting hypotheses for this emergence: (i) resident viruses have been maintained, presumably in wild birds, in Northern Europe throughout the summer of 2021 to cause some of the outbreaks which are part of the most recent autumn/winter 2021 epizootic; (ii) further virus variants were re-introduced by migratory birds. These two sources of re-introduction have driven the HPAI resurgence. Viruses from these two principal sources can be distinguished by their hemagglutinin gene which segregate into two distinct sub-lineages (B1, B2) within clade as well as for different internal genes compositions. The evidence of enzootic HPAI virus circulation during the summer of 2021 indicates a possible paradigm shift in the epidemiology of HPAI in Europe.
Bovine mastitis at calving or early lactation is often associated with intra-mammary bacterial infections (IMI) at drying-off (DO) or during the dry period (DP). The IMI risk is associated with management routines at the herd, but knowledge on how farmers and veterinarians comply with national recommendations is scarce, as is their attitudes to the importance of such routines. Therefore, the main aims of this study were to collect information on farmer routines and attitudes, and on veterinary advice and attitudes to DO and DP. Associations between routines and advice, and demographic herd and veterinary variables were also studied. Web-based questionnaires were sent to 2472 dairy farmers and 517 veterinarians. The answers were summarized descriptively, and associations with demographics were evaluated using univariable regression models. The response rate was 14% for farmers and 25% for veterinarians. Routines and advice were in line with recommendations at the time of the study in many, but not all, areas of questioning. Significant associations between herd routines or veterinary advice and demographic variables were also found. Milking system and post-graduate training were the variables associated with the largest number of farmer and veterinary answers, respectively. In conclusion, the results indicate a need for more education on good routines during DO and DP. It was also clear that the national recommendations valid at the time of the study were in need of revision.
To facilitate cross‐sector integration of surveillance data it is necessary to improve and harmonize the meta‐information provided in surveillance data reports. Cross‐sector integration of surveillance results in sector‐specific reports is frequently difficult as reports with a focus on a single sector often lack aspects of the relevant meta‐information necessary to clarify the surveillance context. Such reporting deficiencies reduce the value of surveillance reports to the One Health community. The One Health Consensus Report Annotation Checklist (OH‐CRAC), described in this paper along with potential application scenarios, was developed to improve the current practice of annotating data presented in surveillance data reports. It aims to provide guidance to researchers and reporting officers on what meta‐information should be collected and provided to improve the completeness and transparency of surveillance data reports. The OH‐CRAC can be adopted by all One Health‐related sectors and due to its cross‐sector design, it supports the mutual mapping of surveillance meta‐information from sector‐specific surveillance reports on federal, national and international levels. To facilitate the checklist completion, OH‐CRAC is also available as an online resource that allows the collection of surveillance meta‐information in an easy and user‐friendly manner. Completed OH‐CRAC checklists can be attached as annexes to the corresponding surveillance data reports or even to individual data files regardless of the data source. In this way, reports and data become better interpretable, usable and comparable to information from other sectors, improving their value for all surveillance actors and providing a better foundation for advice to risk managers.
To honour the 100 years anniversary of the first publication about African swine fever (ASF) a webinar with a particular focus on disease control in the smallholder sector was organised. This article is based on the webinar, summarising the early history of ASF research, reflecting on the current global disease situation and bringing forward some suggestions that could contribute towards achieving control of ASF. The first description of ASF by R. Eustace Montgomery in 1921 laid the foundations for what we know about the disease today. Subsequent research confirmed its association with warthogs and soft ticks of the Ornithodoros moubata complex. During the latter half of the 21st century, exponential growth of pig production in Africa has led to a change in the ASF‐epidemiology pattern. It is now dominated by a cycle involving domestic pigs and pork with virus spread driven by people. In 2007 a global ASF epidemic started, reaching large parts of Europe, Asia, and the Americas. In Europe this epidemic has primarily affected wild boar. In Asia, wild boar, smallholders and industrialised pig farms have been affected with impact on local, national and international pig value chains. Globally and historically, domestic pigs in smallholder settings are most frequently affected and the main driver of ASF virus transmission. Awaiting a safe and efficacious vaccine, we need to continue focus on other measures, such as biosecurity, for controlling the disease. However, smallholders face specific challenges linked to poverty and other structural factors in implementing biosecurity measures that can prevent spread. Improving biosecurity in the smallholder sector thus remains an important tool for preventing and controlling ASF. In this regard interdisciplinary research can help to find new ways to promote safe practices, facilitate understanding and embrace smallholders’ perspectives, engage stakeholders, and adjust prevention and control policies to improve implementation. This article is protected by copyright. All rights reserved
Bluetongue virus (BTV), an arbovirus of ruminants, is a causative agent of numerous epidemics around the world. Due to the emergence of novel reassortant BTV strains and new outbreaks, there is an unmet need for efficacious antivirals. In this study, we used an improved haploid screening platform to identify the relevant host factors for BTV infection. Our screening tool identified and validated the host factor Niemann–Pick C1 (NPC1), a lysosomal membrane protein that is involved in lysosomal cholesterol transport, as a critical factor in BTV infection. This finding prompted us to investigate the possibility of testing imipramine, an antidepressant drug known to inhibit NPC1 function by interfering with intracellular cholesterol trafficking. In this study, we evaluated the sensitivity of BTV to imipramine using in vitro assays. Our results demonstrate that imipramine pretreatment inhibited in vitro replication and progeny release of BTV-4, BTV-8, and BTV-16. Collectively, our findings highlight the importance of NPC1 for BTV infection and recommend the reprofiling of imipramine as a potential antiviral drug against BTV.
Identification of host factors affecting individual SARS-CoV-2 susceptibility will provide a better understanding of the large variations in disease severity and will identify potential factors that can be used, or targeted, in antiviral drug development. With the use of an advanced lung cell model established from several human donors, we identified cellular protease inhibitors, serpins, as host factors that restrict SARS-CoV-2 infection.
Hatching concepts such as on-farm hatching provide an opportunity to supply newly hatched chickens with optimal nutrition that support growth and development of a healthy gut. Brown algae contain bioactive compounds, especially laminarin and fucoidan that may improve intestinal health and immune responses. This study aimed to examine the effects of early access to feed and water posthatch and feed supplementation with algal extract rich in laminarin from Laminaria digitata, on growth performance, organ and microbiota development and antibody production. A total of 432 Ross 308 chicks were allotted to 36 rearing pens in a 2 × 3 factorial design with two hatching treatments and three dietary treatments. During chick placement, half of the pens were directly provided access to feed and water (Early) while half of the pens were deprived of feed and water for 38 h (Late). The chicks were fed three different starter diets until day 6; a wheat-soybean meal-based control diet, a diet with low inclusion of algal extract (0.057%) and a diet with high inclusion of algal extract (0.114%). Feed intake and BW were registered on pen basis at placement, days 1, 6, 12, 19, 26, 33 and 40. To induce antibody responses, all chicks were vaccinated against avian pneumovirus on day 10. Three chicks per pen were selected as focal animals and used for blood sampling on days 10 and 39. On days 6, 19, and 40, two birds per pen were killed and used for organ measurement and caecal digesta sampling for gut microbiota analysis using the Illumina Miseq PE 250 sequencing platform. Results showed that algal extract did not influence gut microbiota, gut development or vaccine-induced antibody responses. However, during the first 38 h, early-fed chicks consumed on average 19.6 g of feed and gained 27% in BW, while late-fed chicks lost 9.1% in BW which lowered BW and feed intake throughout the study (P
We report here Taenia lynciscapreoli metacestode from the lung lobe of a semi-domesticated reindeer (Rangifer tarandus tarandus). The specimen was detected within a development project concerning remote post mortem inspection at a reindeer abattoir in Sweden. Post mortem inspection was performed according to a routine on-site official meat inspection protocol. The species identification to T. lynciscapreoli was confirmed based on the DNA extracted from the metacestode, which was analysed by sequencing of the cytochrome c oxidase subunit 1. Firstly, our finding shows that semi-domesticated reindeer in addition to several other cervids can act as an additional intermediate host for T. lynciscapreoli. Secondly, it further confirms that this parasite is more widely distributed on the Scandinavian peninsula than what has previously been shown. This is in line with a previous molecular finding of adult T. lynciscapreoli from the Eurasian lynx (Lynx lynx) in Sweden and demonstrates that new intermediate host can be detected. Whether the present finding can be regarded as accidental or have created opportunities for an expansion throughout the northernmost Scandinavian Peninsula remains to be seen.
The monitoring of antimicrobial resistance (AMR) in bacterial pathogens of animals is not currently coordinated at European level. To fill this gap, experts of the European Union Joint Action on Antimicrobial Resistance and Healthcare Associated Infections (EU-JAMRAI) recommended building the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet). In this study, we (i) identified national monitoring systems for AMR in bacterial pathogens of animals (both companion and food-producing) among 27 countries affiliated to EU-JAMRAI, (ii) described their structures and operations, and (iii) analyzed their respective strengths, weaknesses, opportunities and threats (SWOT). Twelve countries reported having at least one national monitoring system in place, representing an opportunity to launch EARS-Vet, but highlighting important gaps in AMR data generation in Europe. In total, 15 national monitoring systems from 11 countries were described and analyzed. They displayed diverse structures and operations, but most of them shared common weaknesses (e.g., data management and representativeness) and common threats (e.g., economic vulnerability and data access), which could be addressed collectively under EARS-Vet. This work generated useful information to countries planning to build or improve their system, by learning from others’ experience. It also enabled to advance on a pragmatic harmonization strategy: EARS-Vet shall follow the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards, collect quantitative data and interpret AMR data using epidemiological cut-off values.
This study was conducted to evaluate the performance of a screening protocol to detect and isolate mcr-positive E. coli and Salmonella spp. from animal caecal content and meat samples. We used a multicentre approach involving twelve laboratories from nine European countries. All participants applied the same methodology combining a multiplex PCR performed on DNA extracted from a pre-enrichment step, followed by a selective culture step on three commercially-available chromogenic agar-plates. The test panel was composed of two negative samples and four samples artificially contaminated with E. coli and Salmonella spp. respectively harbouring mcr-1 or mcr-3 and mcr-4 or mcr-5 genes. PCR screening resulted in a specificity of 100% and a sensitivity of 83%. Sensitivity of each agar medium to detect mcr-positive colistin-resistant E. coli or Salmonella spp. strains was 86% for CHROMID® Colistin R, 75% for CHROMagarTM COL-APSE and 70% for COLISTIGRAM. This combined method was effective to detect and isolate most of the E. coli or Salmonella spp. strains harbouring different mcr genes from food-producing animals and food products and might thus be used as a harmonized protocol for the screening of mcr genes in food-producing animals and food products in Europe.
The circulation of livestock pathogens in the pig industry is strongly related to animal movements. Epidemiological models developed to understand the circulation of pathogens within the industry should include the probability of transmission via between-farm contacts. The pig industry presents a structured network in time and space, whose composition changes over time. Therefore, to improve the predictive capabilities of epidemiological models, it is important to identify the drivers of farmers’ choices in terms of trade partnerships. Combining complex network analysis approaches and exponential random graph models, this study aims to analyze patterns of the swine industry network and identify key factors responsible for between-farm contacts at the French scale. The analysis confirms the topological stability of the network over time while highlighting the important roles of companies, types of farm, farm sizes, outdoor housing systems and batch-rearing systems. Both approaches revealed to be complementary and very effective to understand the drivers of the network. Results of this study are promising for future developments of epidemiological models for livestock diseases. This study is part of the One Health European Joint Programme: BIOPIGEE.
South African rivers generally receive waste from inadequate wastewater infrastructure, mines, and farming activities, among others. The uMsunduzi River in KwaZulu-Natal, South Africa, is among these recipients with recorded poor to very poor water quality. To identify parts of the uMsunduzi River that are polluted by Cryptosporidium and Escherichia coli (E. coli), this study mapped out pollutants emanating from point and non-point sources using the Soil and Water Assessment Tool (SWAT). Streamflow calibration in the upper and lower reaches of the catchment showed good performance with R2 of 0.64 and 0.58, respectively. SWAT water quality output data were combined with a Quantitative Microbial Risk Assessment (QMRA) to understand the microbial health implications for people using river water for drinking, recreational swimming, and non-competitive canoeing. QMRA results for Cryptosporidium and pathogenic E. coli showed that the probability of infection for most users exceeds the acceptable level for drinking and recreation as outlined in the South African water quality guidelines, and by the World Health Organization (WHO). The results of this study can be used as a baseline to assess the economic and health implications of different management plans, resulting in better-informed, cost-effective, and impactful decision-making. HIGHLIGHTS SWAT model identified areas of the uMsunduzi River that were polluted by Cryptosporidium and E. coli.; SWAT water quality output data were used in QMRA.; QMRA investigated the impacts of river water on canoeists, recreational swimmers, and those who drink the water.; uMsunduzi River water is not suitable for drinking and recreation according to QMRA results.; These results can inform policies and decision-making within the catchment.;
The Swedish risk management case of Baltic fatty fishes, in which dioxin levels may be too high, is a typical multidimensional food safety decision problem involving public health, economic, environmental and socio-cultural aspects. To effectively address the dioxin food safety problem, the multiple dimensions and conflicting interests of stakeholders have to be considered systematically when evaluating competing risk management options. The objectives of this study were to illustrate the applicability of the Multi-Criteria Decision Analysis (MCDA) method for multidimensional food safety risk management problems, and to evaluate the Swedish dioxin risk management using MCDA. The results show that the MCDA method is indeed a relevant tool for modelling the multifactorial Swedish dioxin problem and for initiating discussions amongst stakeholders to increase the acceptance of chosen strategies. Abolishing the derogation from the European Commission’s maximum limits for the presence of dioxins in Swedish fish is the dominant strategy for risk assessors, whereas the preferences provided by the other stakeholders would suggest a continuation of the derogation without providing consumer information. However, the preferences of female consumers match with the 2011 decision of the Swedish government to ask for a derogation in combination with consumer information. The conclusion drawn from our MCDA analysis is comparable to the government’s decision that—given the gradual reduction in dioxin concentrations in Baltic fish—the decision to continue providing consumer information or not mainly depends on how risk managers balance the preferences of the different stakeholders.
The grey wolf (Canis lupus) persists in a variety of human-dominated landscapes and is subjected to various legal management regimes throughout Europe. Our aim was to assess the effects of intrinsic and methodological determinants on the hair cortisol concentration (HCC) of wolves from four European populations under different legal management. We determined HCC by an enzyme-linked immune assay in 259 hair samples of 133 wolves from the Iberian, Alpine, Dinaric-Balkan, and Scandinavian populations. The HCC showed significant differences between body regions. Mean HCC in lumbar guard hair was 11.6 ± 9.7 pg/mg (range 1.6–108.8 pg/mg). Wolves from the Dinaric-Balkan and Scandinavian populations showed significantly higher HCC than Iberian wolves, suggesting that harvest policies could reflected in the level of chronic stress. A significant negative relationship with body size was found. The seasonal, sex and age patterns are consistent with other studies, supporting HCC as a biomarker of chronic stress in wolves for a retrospective time frame of several weeks. Our results highlight the need for standardization of sampling and analytical techniques to ensure the value of HCC in informing management at a continental scale.
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162 members
Bertil Järplid
  • Department of Pathology and Wildlife Diseases
Jenny Frössling
  • Department of Disease Control and Epidemiology
Erik Olof Agren
  • Department of Pathology and Wildlife Diseases
Mats Isaksson
  • Department of Virology, Immunology and Parasitology
Arianna Comin
  • Department of Disease Control and Epidemiology
Uppsala, Sweden