Re: Porcine dermatitis and nephropathy syndrome in New Zealand

Extract

We wish to record the source of Figures 1a and 2 from the report “Porcine dermatitis and nephropathy syndrome in New Zealand” published in the New Zealand Veterinary Journal 56, 94–99, 2008. These images were kindly provided by AF Julian from Gribbles Veterinary, Hamilton, New Zealand, and illustrate the gross cutaneous and renal lesions that were typical of those seen in pigs in the reported disease outbreak. The images were obtained from a pig with porcine dermatitis and nephropathy syndrome submitted by one of the authors (DEBL) from a similar outbreak of the disease that was examined by Gribbles Veterinary, Hamilton. The failure to properly acknowledge this contribution is regretted.     

Porcine dermatitis and nephropathy syndrome (PDNS) is associated with a systemic cytokine expression profile indicative of proinflammation and a Th1 bias

Porcine dermatitis and nephropathy syndrome (PDNS) is broadly discussed as a porcine circovirus type 2 (PCV2)-associated disease, although PCV2, in contrast to postweaning multisystemic wasting syndrome (PMWS), has to date not been proven to be the aetiologic agent. In order to better understand the complex immunopathology of PDNS, the systemic cytokine expression profiles of (i) five pigs suffering from PDNS, (ii) five animals suffering from naturally acquired PMWS and (iii) five controls were investigated at mRNA and protein levels by means of multiplex real-time RT-PCR and flow cytometric intracellular cytokine detection, respectively. IL-1alpha, IL-6 and IFN-gamma mRNA expressions were found to be elevated in PDNS pigs. At the protein level, an increased capacity of peripheral blood mononuclear cells to produce IL-2, IL-4, IL-6, IL-12, TNF-alpha and IFN-gamma was evident. Hematological investigations revealed a hypochromic anemia while basophils and monocytes were relatively and neutrophils absolutely increased in PDNS pigs. PCV2 antibody levels did not differ significantly between PDNS and PMWS affected animals. Taken results together, the cytokine profile of the PDNS affected animals together with hematological data pointed towards a proinflammatory condition supporting a Th1 bias. Cytokine data of PMWS affected animals exhibited only minor non-significant differences when compared to controls, only IL-10 was significantly decreased at the mRNA level.     

Torque teno sus virus 1 and 2 viral loads in postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS) affected pigs

Torque teno viruses (TTV) are small, non-enveloped viruses with a circular single-stranded DNA genome, which are considered non-pathogenic. However, TTVs have been eventually linked to human diseases. TTVs infecting pigs, Torque teno sus virus 1 (TTSuV1) and 2 (TTSuV2), have been recently associated to porcine circovirus diseases (PCVD). To get more insights into such potential disease association, the aim of this study was to quantify TTSuV1 and TTSuV2 viral loads in serum of pigs affected by two PCVDs, postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). Such study was carried out by means of a newly developed real-time quantitative PCR (qPCR) method. Both TTSuVs were highly prevalent among studied pigs. TTSuV2 viral loads were significantly higher in PMWS affected animals, further supporting the previously suggested association between TTSuV2 and PMWS. On the contrary, TTSuV1 prevalence and loads were not related with the studied PCVDs.     

Porcine circovirus 2-associated disease in Eurasian wild boar.

Porcine circovirus 2 (PCV2) was first identified in high-health herds of domestic swine and was associated with a debilitating disease called postweaning multisystemic wasting syndrome (PMWS). Most subsequent studies have indicated that PCV2 infects only swine but there is little information on porcids other than improved breeds of domestic swine. Multisystemic disease was reported in a group of Eurasian wild boars raised under free-range conditions. Affected young pigs had pneumonia and enteritis and were cachectic. Porcine circovirus 2 was identified in affected tissue by immunohistochemistry and in situ hybridization, and a PCV2-like virus was isolated from pooled organs. The open reading frame (ORF2) of the isolated PCV2 had a 98.7% homology with the ORF2 of a reference PCV2 isolate. These diagnostic data indicate that PCV2 can infect and cause disease in Sus scrofa subspecies other than domestic swine.     

Porcine dermatitis and nephropathy syndrome. clinical and pathological features of cases in the United Kingdom (1993-1998)

This paper documents the salient clinical and pathological features of porcine dermatitis and nephropathy syndrome (PDNS) in 96 pigs submitted from 55 units in the UK from 1993 to 1998. This series of cases pre-dated the emergence of post-weaning multisystemic wasting syndrome (PMWS) in the UK. The morbidity during outbreaks was 1% or less. Affected pigs ranged from 14 to 70 kg in weight and most died after a short clinical illness. Fifty-five pigs had multifocal or coalescing erythematous skin lesions, some progressing to dermal necrosis. Biochemistry showed raised serum urea, creatinine and gamma globulin levels accompanied by proteinuria. All cases showed bilateral renal enlargement with petechiae throughout the cortices. Microscopically these renal lesions ranged in chronology from acute necrotizing glomerulitis and vasculitis with multiple hyaline casts in renal tubules to chronic glomerular sclerosis with interstitial inflammation and fibrosis. Haemorrhagic dermatitis when present was associated with necrotizing vasculitis in the dermal vessels. Vasculitis was sometimes detected in other tissues including subcutis, lymph nodes, spleen, liver, joint synovial membrane, gastric and intestinal submucosa or serosa and meninges but its frequency and distribution varied considerably in individual pigs. Immunostaining showed deposits of IgG and IgM in damaged glomeruli, renal casts and skin lesions. The aetiology and pathogenesis of the condition remain unknown but the histopathological and immunological findings suggest a systemic immune-complex disorder resulting in vasculitis with particular predilection for kidney and skin.     

Epidemiology of bovine brucellosis in Northern Ireland between 1990 and 2000

Between 1990 and 2000, 317 herds of cattle in Northern Ireland were identified as being seropositive to Brucella abortus, and 68 per cent of them were attributed to transmission from neighbouring herds or to local spread. Of particular significance were three primary outbreaks in 1997, which resulted in significant secondary and tertiary spread. Three spatial clusters were identified, corresponding to two of the primary outbreaks, and the herd density and within-herd spread were highest in the largest cluster. Abortions in an infected herd and the disease-risk status of the disclosure test were positively associated with an increased within-herd prevalence.     

Bovine spongiform encephalopathy in Northern Ireland: epidemiological observations 1988-1990.

This study describes the epidemiological features of bovine spongiform encephalopathy (BSE) in Northern Ireland where the first case occurred in November 1988. They were very similar to those observed in Great Britain except that the annual incidence of BSE in 1990 in Northern Ireland, 2.3 confirmed cases per 10,000 adult cows, was approximately one 10th of that in Great Britain. The findings were also consistent with the current hypothesis that affected cattle had been exposed to a scrapie-like agent via cattle feedstuffs containing ruminant-derived protein. However, a preliminary investigation of the potential sources of infection for cattle in Northern Ireland did not provide any conclusive evidence.     

神木县PRRSV与PCV-2的血清学调查

为调查猪繁殖与呼吸综合征(PRRS)和猪圆环病毒病(PCVD)在陕西省神木县的流行情况,用ELISA方法对从该地区规模化猪场收集的200份血清进行了猪繁殖与呼吸综合征病毒(PRRSV)和猪圆环病病毒(PCV-2)抗体检测,结果显示,PRRSV抗体阳性率为26.8％;PCV-2抗体阳性率为85.5％,初步证明PCV-2感染在神木县十分普遍,部分猪场PRRSV感染比例较高,应加强对这两种疾病的防疫工作.     

Occurrence of porcine dermatitis and nephropathy syndrome in Hungary

In the past few years a characteristics, often fatal disease associated with cutaneous lesions and nephropathy has been observed in several large pig herds and household pig stocks of Hungary. In addition to general symptoms and slight fever in several cases, the disease was characterised by cutaneous lesions occurring mostly on the ventral part of the thorax and abdomen, on the extremities and ear pinnae, and in the nasal and perianal region. In the acute phase, circumscribed hyperaemic, confluent, crust-covered areas were seen. Histological examination revealed necrosis of the epithelial layer and lympho-histiocytic vasculitis in the corium, here and there accompanied by thrombosis and fibrinoid degeneration. The kidneys were pale brown and harder to tear, with cortical petechiae in most cases. By histopathological examination, intra- and extracapillary glomerulonephritis accompanied by fibrinoid exudation was seen. Some of the renal tubules were dilated, others were atrophied, and in advanced cases proliferation of the intertubular connective tissue and inflammatory cell infiltration also occurred. Necrotic vasculitis was also observed in some cases. By immunohistochemical examination IgA, IgG and IgM, and in a single case C3 belonging to the complement system were observed in the pathologically changed skin areas and kidneys. By polymerase chain reaction (PCR), porcine circovirus type 2 (PCV-2) was detected. Bacteriological and serological examinations did not reveal infections of aetiological importance.     

猪皮炎肾病综合征的病理学观察

对临床表现为猪皮炎肾病综合征的患病猪进行了剖检病变的观察,采用常规石蜡切片法对患病猪的病理组织学变化进行了研究,同时采用PCR方法对PCV2进行了检测。结果显示:剖检病理变化主要变现为皮肤散在分布不规则的圆形暗红色病灶,病灶中央凹陷,黄色结痂;肾表面可见大小不等的灰白色病灶;肺间质明显增宽、水肿,肺组织呈灰红色斑驳状或呈现为虾肉样变。组织病理学变化表现为肾脏呈现肾小球肾炎,真皮及皮下血管表现为坏死性脉管炎,淋巴组织中淋巴滤泡数量减少,淋巴细胞缺失、巨噬细胞浸润,以及典型的间质性肺炎。PCR检测结果为PCV2阳性。结果表明:该猪场发生了PCV2感染并引起了典型的猪皮炎肾病综合征病理变化。