Ostreid herpesvirus-1 microvariant surveillance in Pacific oysters (Magallana gigas, Thunberg, 1793) in Australia in 2011.

OBJECTIVE: To demonstrate that OsHV-1 microvariant was limited to the known infected areas in New South Wales at the time of the survey in 2011. DESIGN: A 2-stage survey to demonstrate probability of infection at 2% design prevalence within oyster growing regions and to detect at least one infected region (4% design prevalence) with 95% confidence. SAMPLE POPULATION: Magallana gigas in nominated oyster growing regions in New South Wales, South Australia and Tasmania as approved by the Aquatic Consultative Committee on Emergency Animal Diseases and documented in a national surveillance plan. PROCEDURE: Field sampling for active surveillance and laboratory selection of appropriate tissues using methods to minimize potential for cross contamination. Published methods for qPCR and conventional PCR for OsHV-1 microvariant. Stochastic analysis of survey results to demonstrate probability of detection in the areas tested. RESULTS AND CONCLUSIONS: OsHV-1 microvariant was not detected in a total 4121 samples according to the case definition developed for the survey. However, in NSW a screening qPCR for OsHV-1 detected 13 samples that reacted. These samples were negative at 2 laboratories in the qPCR and conventional PCR assays used in the case definition for the survey. We concluded that oyster production areas of Australia outside the infected area in NSW met the criteria for self-declaration of freedom at the time of the survey in 2011. CLINICAL RELEVANCE: This activity illustrated achievements in surveillance for an emerging emergency animal pathogen where epidemiological and test validation data were limited, but where data was required to inform the emergency disease response. It also illustrated the challenges faced by investigators in interpreting surveillance results using tests with limited validation. It was guided by and has informed improvements in surveillance and emergency disease preparedness.

Hyperoxaluria, hyperglycoluria and renal oxalosis in Gilbert's potoroos (Potorous gilbertii).

CASE REPORT: Six Gilbert's potoroos (Potorous gilbertii) in a captive colony, five of which were closely related, died or were euthanased with severe renal disease. Clinical signs were mostly non-specific. Renal calculi were seen on ultrasound of two affected potoroos and oxalate crystalluria was seen in two of three affected potoroos that had urine samples examined. Necropsies revealed extensive severe renal oxalosis in all affected potoroos. These findings and markedly increased concentrations of glycolate in the urine of the four affected potoroos for which it was measured, confirmed a disorder of oxalate metabolism and suggested a condition similar to primary hyperoxaluria type 1 in humans. Liver alanine : glyoxylate aminotransferase activity and intracellular location were assessed as normal in one affected potoroo, which is inconsistent with human primary hyperoxaluria type 1. Although a condition similar to human primary hyperoxaluria type 2 or 3 was not ruled out, other clinicopathological findings were not consistent with those seen in humans with these conditions. A lack of faecal oxalate-degrading activity was observed in two affected potoroos in which it was measured, whereas oxalate-degrading activity was variably present in healthy captive and wild potoroos. CONCLUSION: Although the pathogenesis of renal oxalosis in these cases was not clear, the biochemical findings of elevated urinary oxalate and glycolate excretion indicate an abnormality of oxalate metabolism. The familial pattern of disease suggests it could be an inherited condition.

Protective effect of enprostil against aspirin-induced gastroduodenal mucosal injury in man. Comparison with cimetidine and sucralfate.

A single-blind endoscopic study was undertaken to test the relative efficacy of enprostil, a synthetic analogue of prostaglandin E2, cimetidine, and sucralfate in the prevention of aspirin-induced gastroduodenal mucosal injury. Fifty healthy, non-smoking male volunteers completed the study after having been randomly assigned to receive two weeks of therapy with one of the following regimens: enprostil 35 micrograms twice daily; enprostil 35 micrograms in the morning; cimetidine 200 mg three times daily and 400 mg at night; sucralfate 1 g four times daily; or placebo. In the second week, aspirin (900 mg three times daily) was also administered. Endoscopies were performed before and after the aspirin phase of the study, and lesions (mucosal erosions plus submucosal hemorrhages) were counted in the stomach and duodenal bulb. All treatments were superior to placebo (p less than 0.05). The mean number of lesions in the 70-micrograms enprostil group (8.5) was significantly less than in the 35-micrograms enprostil group, (11.1), the sucralfate group (12.4), or the placebo group (16.0); the benefit over cimetidine (10.1), however, was not statistically significant. The protective effect of enprostil was greatest in the antrum, the site of maximal mucosal injury. Gastrointestinal side effects were reported in all groups, though abdominal pain and dyspepsia were noted more frequently in those taking enprostil.

The spatial and temporal variation of the distribution and prevalence of Atlantic salmon reovirus (TSRV) infection in Tasmania, Australia.

Atlantic salmon reovirus (TSRV) has been consistently isolated from Atlantic salmon in Tasmania, since first identification in 1990 under the Tasmanian Salmonid Health Surveillance Program (TSHSP). The distribution and prevalence of TSRV was identified using TSHSP data. A data set of 730 fish submissions tested over a period of 15 years was reviewed and analysed to describe the spatial and temporal variation of TSRV in Tasmanian salmonid aquaculture production units. The virus was present throughout Tasmania with the highest reported prevalence of the virus in the south-east region of Tasmania.

Gross pathology and its relationship with histopathology of amoebic gill disease (AGD) in farmed Atlantic salmon, Salmo salar L.

Gross pathological assessment of amoebic gill disease (AGD) is the only non-destructive, financially viable method for rapid and broad-scale disease management of farmed Atlantic salmon, Salmo salar L., in Tasmania. However, given the presumptive nature of this diagnosis, the technique has been considered questionable. This study investigated the degree of conformity between clinical signs and histological lesions observed in a commercial setting. Three groups of Atlantic salmon (n = 42, 100 and 100, respectively) were collected from various farm sites in southern Tasmania between December 2001 and April 2003. Micro-stereoscopic analysis showed that grossly affected tissue regions correspond to areas of hyperplastic lamellar fusion, generally in association with attached Neoparamoeba sp. Agreement between gross signs of AGD and histopathological diagnosis was compared. Kappa analysis indicated moderate to good agreement between methods (kappa = 0.52-0.74). Individual cases of disagreement were further scrutinized and several factors were found to influence the level of agreement between the two methods. Stage of disease development, lesions derived from other pathogens, assessor interpretation/experience, sampling methods, histological technique and/or experience were potential confounding factors. It was concluded that clinical diagnosis is acceptable as a farm-monitoring tool only. Removal of grossly affected tissue and subsequent histological examination is recommended to improve diagnostic accuracy.

Acute and chronic stress in duodenal ulcer disease.

Acute and chronic life event stressors were objectively assessed in a sample of duodenal ulcer patients and community controls. Stress was assessed on two dimensions, "personal threat" and "goal frustration." Chronic stressors (those of 6 months' duration or more) involving high goal frustration were significantly and independently associated with the onset and relapse of duodenal ulcers, as were acute events of high immediate but transient personal threat.

Suppression of emotions in essential dyspepsia and chronic duodenal ulcer. A case-control study.

It remains controversial whether psychologic factors contribute to the onset or chronicity of non-ulcer dyspepsia (NUD) and duodenal ulcer. Although such patients on conventional psychologic testing have no clearly defined specific personality type, an inability to express emotion, which may result in excessive autonomic arousal, has been suggested to be important on theoretic grounds. The aim of this study was to assess whether the latter defect is associated with the subgroup of NUD patients with essential dyspepsia and with patients with chronic duodenal ulcer. Eighty-one patients with essential dyspepsia and 53 patients with duodenal ulcer studied after endoscopy were compared with 82 randomly selected dyspepsia-free community controls. All were assessed with the Courtauld emotional control scale, a valid and objective self-report measure. Control of anger, anxiety, unhappiness, and total emotional control over negative reactions were similar in all three groups. It is concluded that patients with essential dyspepsia and duodenal ulcer who present for investigation are unlikely to repress emotional reactions consciously.