Epidemiology of typical and atypical rotavirus infections in New Zealand pigs

Polyacrylamide gel electrophoresis (PAGE) and enzyme-linked immunosorbent assay (ELISA) were employed to investigate the epidemiology of typical and atypical rotavirus infections in five piggeries. Of 152 faecal samples examined, 46 (30 per cent) were positive by ELISA for group A rotavirus. Rotaviruses with electrophoretic patterns resembling groups A, B and C were detected. At least two and up to five different rotavirus electrophoretypes (typical and/or atypical) were detected in each of the five piggeries. Out of 152 faecal samples examined, 28 (18 per cent) contained rotaviruses with group A electrophor etypes, 9 (6 per cent) with group C but only 1 with Group B. Six samples contained both group A and group C rotaviruses. No common electrophoretypes of group A or C rotaviruses were detected in these five piggeries. The PAGE technique was also used to analyze group A rotavirus isolated sequentially from another piggery over a three year period. A singIe electrophoretype was found during the first two years, but in the third year a different electrophoretype was detected.     

A search for infections of Trichinella spiralis in New Zealand pigs

Abstract

Extract

Following the occurrence of one case of human trichinosis in New Zealand in 1931 (Lynch, 1932 Lynch, P. P. 1932. N.Z. med. J., 31: 216–216.  [Google Scholar]), a search was made for the larvae of Trichinella spiralis in the diaphragms of pigs. The examinations were made by pressing out pieces of muscle between two glass slides, and examining them under the microscope using a low-power objective. Samples from nearly 20,000 pigs were examined without any infections being found (N.Z. Dept. Agric, 1932 N.Z. Dept. Agric. 1932. Annual Report for 1931–32, : 57–57.  [Google Scholar]).     

The incidence of Leptospira hyos and Leptospira pomona infections in pigs in New Zealand

Extract

The occurrence of leptospirosis in New Zealand was first reported by this station in 1950. when Leptospira pornona was isolated from a calf with haemoglobinuria. Since then it has been demonstrated in most farm animals, including pigs, on many occasions.     

Neospora caninum infections in Australia and New Zealand

OBJECTIVE: To review the current state of knowledge of Neospora caninum infections with particular reference to Australia and New Zealand. PROCEDURE: Several databases were searched electronically including Medline, Current Contents, Vet CD using several key words (Neospora caninum, neosporosis, abortion, cattle, dogs) and authors names. References in original articles were also traced and use made of the author's own original research in the field. CONCLUSION: N caninum is recognised worldwide and is also widespread, in particular in dairy cattle, in Australia and New Zealand. It has been reported in both countries retrospectively (in dogs) from the early 1970s. Abortion storms in dairy herds appear to be the most common feature. Recent reports indicate that the dog is the definitive host, in which the sexual cycle is completed. Further studies are however required to establish important aspects of the epidemiology, such as mode of transmission. In the absence of an effective vaccine, the most effective control strategy is selective culling of infected animals and the prevention of access of dogs to expelled placentas and foetuses and, possibly, to raw beef.     

Monitoring the health of pigs in New Zealand abattoirs

A survey of the prevalence of pneumonia, ascariasis, mange, oesophagogastric ulcers and porcine intestinal adenomatosis was carried out during 1986-90 on 2792 baconer pigs from 46 herds located in Canterbury, North Otago and the southern part of the North Island of New Zealand. Enzootic pneumonia had an overall prevalence of 45%, ascariasis 13% and clinical mange 13%. Oesophagogastric ulceration was a problem in certain herds only, whilst porcine intestinal adenomatosis and associated ileal lesions had a very low prevalence (7%). Examination of 534 snouts for atrophic rhinitis revealed a prevalence of 31%, but most of the lesions recorded were very mild.     

Relative prevalence of typical and atypical strains among rotaviruses from diarrheic pigs in conventional swine herds

Polyacrylamide gel electrophoresis was conducted on genomic RNA extracted from rotaviruses detected in diarrheic pigs from conventional swine herds. Ninety samples contained sufficient virus for RNA band visualization and genome classification. Genome profiles were characteristic of typical group A rotaviruses in 67.8% of the 90 samples, of group B rotaviruses in 10.0%, and of group C rotaviruses in 11.1%. In 11.1% of the samples, the presence of more than 11 bands suggested concurrent infection with more than 1 strain of rotavirus. In infections among nursing pigs, 76.4% were group A rotaviruses, 7.4% were group B, 7.4% were group C, and 8.8% were coinfections. In infections among weaned pigs, 40.9% were group A, 18.2% were group B, 22.7% were group C, and 18.2% were coinfections. Coelectrophoresis with prototype OSU and Gottfried strains revealed a great diversity in electropherotype among field strains of rotavirus.     

Three cases of a presumptive atypical myopathy in New Zealand horses

CASE HISTORY: Three weanling Thoroughbred fillies were presented during autumn with depression, muscle rigidity and, in one case, colic symptoms and cardiovascular shock.

CLINICAL FINDINGS: All fillies had abnormal physical examinations that included elevated heart rates and respiratory rates coupled with muscle rigidity through the back and rump. Biochemistry revealed markedly elevated creatinine kinase and aspartate aminotransferase which indicated a myopathy.

DIAGNOSIS AND TREATMENT: All three horses were diagnosed with presumptive equine atypical myopathy. The horses received supportive therapy as per the literature available at the time regarding this condition; two responded to supportive therapy and survived, and one was euthanased due to a rapid deterioration in clinical status.

PATHOLOGICAL FINDINGS: Following post mortem of one case, histology of the trapezius muscle demonstrated an acute, severe myofibre degeneration.

CLINICAL RELEVANCE: Atypical myopathy and a very similar disorder termed seasonal pasture myopathy in North America are potentially fatal, pasture-related syndromes that have been described in Europe and America but have not been previously described in New Zealand. This report describes three presumptive cases of this unique syndrome in New Zealand for the first time; it outlines the characteristics of the condition; and includes recently published information regarding diagnosis and treatment.     

Molecular detection of norovirus in sheep and pigs in New Zealand farms

Human norovirus (NoV) is reportedly the major cause of non-bacterial gastroenteritis outbreaks worldwide and is commonly associated with water- and food-borne transmission via the faecal-oral route. Aside from humans, norovirus has been detected in pigs, cattle and mice. The close relatedness of some human and animal noroviruses has raised concerns about potential zoonotic transmission. Our laboratory recently reported the development of a multiplex real-time RT-PCR for the detection and genotyping of norovirus of genogroups I-III. Here we report a study of 56 faecal specimens from pigs and sheep that were collected and screened for noroviruses using this assay. Norovirus was found in 2/23 (9%) of porcine specimens (all were genogroup II) and in 8/33 (24%) of ovine specimens (all were genogroup III). Samples tested positive for norovirus were verified by conventional RT-PCR with different primer sets. Genomes of representative porcine and ovine norovirus strains underwent partial sequence analysis (343 and 2045 bases, respectively). This is the first report describing norovirus in sheep.     

Isolation of rotavirus from calves, foals, dogs and cats in New Zealand

The incidence of rotaviruses in calves, foals, dogs and cats in the Dunedin urban and rural areas was investigated using electron microscopy and enzyme-linked immunosorbent assays. Of the 283 faecal specimens examined, 26% were positive for rotavirus. Comparison of the genetic electropherotypes was made by separating the viral dsRNA segments using polyacrylamide gel electrophoresis. It is possible that rotavirus infection is a zoonotic disease.     

Epidemiology of Mycobacterium bovis infections of pigs and wild boars using a molecular approach

A molecular epidemiological approach was applied to establishing a possible role for the wild boar as a natural reservoir of Mycobacterium bovis in Sierra de Villuercas, Western Spain; an area free of farmed cattle and wild deer populations. Spoligo and VNTR typing were used over a three year period to study the epidemiological relationship between the occurrence of bovine tuberculosis (TB) in extensively bred Iberian pigs and indigenous wild boar. The 37 sampled wild boar showed different degree of calcified granulomatous lesions in retropharyngeal, mediastinal and pulmonary lymph nodes. The 25 sampled Iberian pigs showed calcified lesions, mainly in the respiratory tract. Lesions located in the mesenteric lymph nodes appeared secondarily. M. bovis was isolated from all affected animals. Twenty-five and 37 isolates of M. bovis were obtained from domestic pigs and wild boar, respectively. Our findings provide evidence that supports the possibility of cross infection between wild boar and domestic pig populations. This is contrary to the generally held belief that swine represent an epidemiological dead end host and play no role in the epidemiology of M. bovis.     

Problems of interpretation of ileal lesions in New Zealand slaughter pigs

The term proliferative enteritis (PE) is a collective one used to describe a group of related diseases characterised by adenomatous intestinal epithelium frequently seen to contain intra-cellular campylobacter-like organisms. It embraces four related disease syndromes, porcine intestinal adenomatosis (PIA), necrotic enteritis (NE). regional ileitis and proliferative haemorrhagic enteropathy (PHE), all affecting mainly the terminal ileum.     

Experimental rotavirus infection in three-week-old pigs

Thirteen 3-week-old pigs that had been allowed to nurse for the first 16 to 18 hours after birth were orally inoculated with 1 x 10(6.5) TCID50 of porcine rotavirus. All developed diarrhea, anorexia, and vomiting by postinoculation (PI) hour 30. These signs had abated by PI day 6. Villus blunting in the small intestine was most severe in the jejunum and ileum of pigs euthanatized between PI days 3 and 5. Villi had returned to nearly normal length by PI day 6, although fused villi were seen in a few locations in the distal portion of the jejunum and in the ileum. Virus was detected in the feces of inoculated pigs by isolation in cell cultures and by electron microscopy during the 7-day course of the experiment. There was 1 extraintestinal virus isolation from the lung of 1 pig at PI day 2. Infection and disease developed in the presence of serum-neutralizing antibody obtained by nursing seropositive sows. There was no significant change in neutralizing antibody titers in the 3-week-old pigs over the course of the experiment. In this experimental work, a model to study rotavirus infection in 3-week-old pigs has been developed.     

Observations on the incidence of Ascaris lumbricoides in New Zealand pigs

Extract

It is often considered that Ascaris lumbricoides is one of the most common parasites of pigs and also one of the most serious. There is no doubt that this is so in many parts of the world but until recently there was little information available on its importance in New Zealand. It is well recognized that the parasite is pathogenic for pigs, particularly for younger pigs and during the period when the worms are immature and undergoing their migration through the lung tissue.     

动物轮状病毒病的流行病学及综合防治

轮状病毒病(Rotavirus diseases)是由轮状病毒引起的各种动物的腹泻性疾病,如小牛、小猪、羔羊、小狗或家禽等。通过试验发现也可引起非人类灵长目Tupaiabelangeriyunalis的严重腹泻病,因此轮状病毒病是一种人畜共患传染病,不仅感染率高,发病率也相当高,对人类健康和畜牧业危害较大。本病最早(1943年)在患腹泻的儿童中发现,     

The occurrence of mycoplasmas in the lungs of pigs in New Zealand

Attempts were made to recover and serologically identify mycoplasmas from the lungs of 50 pigs with mycoplasmal pneumonia and from 50 lungs without gross evidence of pneumonia. Mycoplasma hyopneumoniae and M. hyorhinis were respectively cultured from 30% and 50% of pneumonic lungs and the former species was also recovered from 12% of non-pneumonic lungs. Three other isolates (one from pneumonic and two from non-pneumonic lungs) differed in colonial morphology from M. hyopneumoniae and M. hyorhinis. The viability of these isolates could not be maintained on subculture and they were not identified serologically. The indirect immunofluorescence test was found to be highly specific for the identification and differentiation of M. hyopneumoniae and M. hyorhinis.     

The occurrence of Trlchinella spiralis in New Zealand pigs,rats and cats

Extract

In October, 1964, a case of human trichinosis was diagnosed in Auckland and it seemed likely that the disease had been contracted by eating locally raised pigmeat which was infected with Trichinella spiralis. Subsequently, the Parasitology Department of this Centre, in association with the Meat Inspection Division of the Department of Agriculture, conducted a survey on adult pigs killed in the Auckland Province to determine whether infection of pigs occurred in the area and to try to obtain an indication of its prevalence.