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P Wallgren,
F Hasslung,
G Bergström,
A Linder,
K Belak, C Hård af Segerstad,
M Stampe,
B Molander,
T Björnberg Kallay,
E Nörregård,
C J Ehlorsson,
M Törnquist,
C Fossum,
G M Allan,
J A Robertsson
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ABSTRACT: Postweaning multisystemic wasting syndrome (PMWS) is causally associated with porcine circovirus type 2 (PCV2) infection of pigs. PCV2 has been present in the Swedish pig population for at least ten years. Despite this, no signs of PMWS were observed in pigs of Sweden until 2003. Since then the disease has spread slowly in Sweden. The pig population of Sweden is geographically isolated, the density of pigs and the pathogen load in the country is low and the trade of animals is organised in a restricted way. To date, there has been little information placed in the peer-reviewed literature on the study of the spread of PMWS in a country during the early phase of the disease outbreak, mainly because diagnosis of PMWS has only occurred after the disease has been recognised on a number of farms. This manuscript documents the studies to date on the PMWS outbreak in Sweden which has been closely monitored since the initial outbreak of diseases on a single farm in 2003 was diagnosed. In Sweden PMWS was officially reported for the first time at a progeny test station during December 2003. One year later sixteen herds have been diagnosed and reported to the authorities: one progeny test station, one nucleus herd, thirteen piglet producers or integrated herds and one specialised fattening herd. Fifteen suspected cases have been deemed negative for PMWS with disease scenarios associated with Lawsonia intracellularis, Brachyspira pilosicoli, Mycoplasma hyopneumoniae, shortcomings in feed composition etc. To date, one year after the index case was reported ten other herds suspected for PMWS are under observation. The PMWS cases are concentrated into the southern part of Sweden. However, the disease is spreading slowly, and in general there are no obvious physical links between affected herds. The data generated to date in Sweden suggest that introduction of a new contagious microbe into the country that is responsible for the PMWS outbreaks appears unlikely, as does the spread of PMWS via semen.
The Veterinary quarterly 01/2005; 26(4):170-87. · 1.47 Impact Factor
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ABSTRACT: Within the framework of the active surveillance for transmissible spongiform encephalopathies in sheep in Sweden, 4 cases of the atypical form of scrapie, Nor98, were identified during 2003. Nor98 is a recently recognized and poorly understood variant of scrapie, first described in Norway. The cases were positive by the rapid test (enzyme-linked immunosorbent assay). Immunohistochemical staining showed diffuse thin-granular staining of the cerebellar cortex. Western immunoblotting analysis of specimens of brain stem and cerebellum showed a light band of approximately 12 kDa. Typical scrapie was ruled out based on the confirmatory testing. The affected ewes were from 4 different flocks. They were between 7 and 9 years old. Two were of the ARQ/ARQ genotype, 1 ARR/ARQ, and 1 ARR/AHQ. Two ewes had shown ataxia, and the other 2 had no clinical signs. Whole-flock slaughter was applied, and testing of the flock mates did not reveal additional cases. Nor98 differs from typical scrapie in its epidemiology, frequency of genotypes of sheep affected, clinical signs, microscopic lesions, distribution of scrapie prion protein in the brain, and characteristics of the immunostaining and immunoblotting profiles.
Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 12/2004; 16(6):562-7. · 1.21 Impact Factor
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ABSTRACT: The aim of this study was to find suitable and reliable tools for demonstrating Lawsonia intracellularis in routine clinical diagnosis. Firstly, a method to prepare tissue samples before a polymerase chain reaction (PCR) was evaluated in pigs submitted for necropsy. Secondly, seven different faecal preparation methods and four different DNA polymerases were tested in single or nested PCR, with co-amplification of a mimic molecule. Thirdly, in selected pigs submitted for necropsy, tissue and faecal samples were examined histopathologically and by PCR, and blood samples were analysed serologically. Detection of L. intracellularis in tissue preparations by PCR showed good specificity and correlated to lesions found at necropsy. The sensitivity in spiked tissue samples was 10(1)-10(2) mimic molecules per tube. In faecal samples, nested PCR on boiled lysate gave the best result with a sensitivity of 10(2)-10(3) mimic molecules per reaction tube. However, because of the time-consuming procedure and the increased risk for contamination, a commercially available kit was preferred for routine diagnoses, despite a somewhat lower detection rate in subclinically infected pigs. In a few cases, the serological results differed from those obtained by PCR and by necropsy but the reason for this is not clear. This study indicates that the best method for diagnosis of acute enteritis in growers is PCR on faecal or tissue samples. To determine the presence of the bacteria in a herd, serology or repeated faecal sampling for PCR from target animals, or both, should be used.
Veterinary Microbiology 10/2004; 102(3-4):189-201. · 3.33 Impact Factor
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ABSTRACT: Diarrhoea among growing pigs (8-13 weeks old) is a significant problem in many herds. Nine herds with poor performance and diarrhoea among growing pigs were selected on the basis of their piglet mean age at a body weight of 25 kg, compared to the overall mean age in Swedish herds. In addition, four herds with good average performance and no problems with diarrhoea were selected. Pigs were necropsied and samples for histology and microbiology were collected. Based on the necropsy findings, the pigs from the good performing herds were all judged to be healthy. The presence of Brachyspira pilosicoli and Lawsonia intracellularis was significantly correlated to poor performing herds and the results indicate that these microbes are main pathogens involved in enteric diseases among Swedish grower pigs. In addition, concomitant infections with other presumptive pathogens were commonly found.
Research in Veterinary Science 05/2003; 74(2):163-9. · 1.65 Impact Factor
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ABSTRACT: The clinical, radiological and pathological findings in 12 dogs with canine leucocyte adhesion deficiency (CLAD) from six litters are described. All the dogs were younger than 15 weeks at admission, all had been febrile and 11 had been treated with antibiotics. Seven had been treated for omphalophlebitis. At admission, all had gingivitis, lymph node enlargement and profound neutrophilia. Ten dogs were radiographed and showed various skeletal lesions compatible with metaphyseal osteopathy, craniomandibular osteopathy and osteomyelitis. Four dogs had clinical signs of respiratory distress and seven exhibited a mild interstitial pneumonia at necropsy. Six dogs had skin wounds, with strikingly few neutrophils seen on stained sections. All dogs were euthanased before six months of age due to severe and incurable infections. The clinical signs, radiological features and haematology were strongly suggestive of CLAD. The diagnosis was confirmed by granulocyte function tests and flow cytometry, which revealed impaired adhesion, impaired C3b-mediated phagocytosis and absence of adhesion proteins CD11b/CD18.
Journal of Small Animal Practice 06/2000; 41(5):211-7. · 1.00 Impact Factor
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ABSTRACT: We compared two strains of avian influenza A viruses of subtype H10 by exposing mink to aerosols of A/mink/Sweden/3,900/84 (H10N4) naturally pathogenic for mink, or A/chicken/Germany/N/49, (H10N7). Lesions in the respiratory tract during the first week after infection were studied and described. Both virus strains caused inflammatory reactions in the lungs and antibody production in exposed mink but only mink/84 virus was reisolated. The lesions caused by mink/84 virus were more severe with higher area density of pneumonia, lower daily weight gain, and more virus in the tissues detected by immunohistochemistry. The results indicate that mink/84 (H10N4), but not chicken/49 virus (H10N7), established multiple cycle replication in infected cells in the mink.
Archives of Virology 02/1998; 143(4):653-66. · 2.11 Impact Factor
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ABSTRACT: Calves persistently infected with bovine viral diarrhoea virus (BVDV) often appear small for their age and it is possible that the virus interferes with their body metabolism by affecting the production of hormones. In this study, the serum concentrations of thyroxine (T4) and triiodothyronine (T3) were measured in calves with transient or persistent BVDV infections. The mean (SD) concentrations of T3 and T4 were lower (P < 0.001) in the persistently infected calves (1.79 [0.67] and 69.2 [23.8] nmol litre-1, respectively) from three dairy herds than in age-matched control calves (2.39 [0.72] and 93.4 [22.1] nmol litre-1, respectively). In each herd, the thyroid hormone levels were also lower in the persistently infected calves than in the controls, the differences being significant (P < 0.05) with the exception of the T3 level in one herd. The girth of the infected calves over the heart was less (P < 0.001) than that of the controls, and, among the infected calves but not among the controls, there was a significant correlation between heart girth and the levels of T3 (r = 0.72, P < 0.001) and T4 (r = 0.60, P < 0.01). Six calves not previously exposed to BVDV were infected through nose-to-nose contact with a persistently infected calf. Their T3 and T4 levels were decreased seven days (P < 0.05 and not significant, respectively) and nine days (P < 0.001 and P < 0.01, respectively) after the infection, when the clinical signs of the disease appeared.
Research in Veterinary Science 03/1995; 58(2):186-9. · 1.65 Impact Factor
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ABSTRACT: Investigation of 12 Irish setter puppies from six litters with severe recurrent infections, neutrophilia and low body weight revealed a leucocyte adhesion protein deficiency with a total lack of CD11b and CD18. Their neutrophil function was severely impaired with a totally absent capacity to ingest C3b-opsonized particles, a significantly impaired capacity to ingest IgG-opsonized particles and significantly diminished adherence to nylon wool when compared with neutrophils from healthy control dogs. The chemiluminescence of patient neutrophils activated by C3b-opsonized particles was, consequently, significantly decreased compared with that of control neutrophils, while the respiratory burst assayed by phorbolmyristate acid (PMA) stimulated nitroblue tetrazolium (NBT)-reduction was normal in the patient group. Random migration and chemotactic responses of patient and control neutrophils, were similar. The etiology, pathogenesis and clinical manifestations of the Irish setter leucocyte adhesion deficiency were similar to that of the leucocyte adhesion deficiency in humans.
Veterinary Immunology and Immunopathology 06/1992; 32(3-4):261-80. · 2.08 Impact Factor
