Avian influenza in Australia: a summary of 5 years of wild bird surveillance.

BACKGROUND: Avian influenza viruses (AIVs) are found worldwide in numerous bird species, causing significant disease in gallinaceous poultry and occasionally other species. Surveillance of wild bird reservoirs provides an opportunity to add to the understanding of the epidemiology of AIVs. METHODS: This study examined key findings from the National Avian Influenza Wild Bird Surveillance Program over a 5-year period (July 2007-June 2012), the main source of information on AIVs circulating in Australia. RESULTS: The overall proportion of birds that tested positive for influenza A via PCR was 1.9 ± 0.1%, with evidence of widespread exposure of Australian wild birds to most low pathogenic avian influenza (LPAI) subtypes (H1-13, H16). LPAI H5 subtypes were found to be dominant and widespread during this 5-year period. CONCLUSION: Given Australia's isolation, both geographically and ecologically, it is important for Australia not to assume that the epidemiology of AIV from other geographic regions applies here. Despite all previous highly pathogenic avian influenza outbreaks in Australian poultry being attributed to H7 subtypes, widespread detection of H5 subtypes in wild birds may represent an ongoing risk to the Australian poultry industry.

Difficulties in the diagnosis of pseudoachalasia.

OBJECTIVES: We undertook this study to determine the utility of various clinical findings and tests in the diagnosis of pseudoachalasia. METHODS: We reviewed the clinical, endoscopic, esophagographic, CT, and manometric findings of five patients with pseudoachalasia of malignancy. These patients were identified from our large group of 206 patients with manometrically diagnosed achalasia who were seen over the past 8 yr. For each pseudoachalasia patient, the two consecutively seen patients with idiopathic achalasia were chosen to comprise a control group. RESULTS: The pseudoachalasia patients, as compared to the control group, had shorter duration of dysphagia (9.6 +/- 8.6 months vs 54.3 +/- 44.2 months, p < 0.05). They had similar weight loss (15.6 +/- 12.8 lbs vs 14.3 +/- 18.4 lbs, p = NS), but weight loss/time, where time is months of symptoms, was greater in the pseudoachalasia group (1.8 +/- 1.8 lbs/month vs 0.5 +/- 0.5 lbs/month, p < 0.05). There was, however, substantial overlap between the groups in all these parameters. Barium esophagography failed to reveal cancer in any of the pseudoachalasia patients. There was difficult passage of the endoscope through the gastroesophageal junction in all patients with pseudoachalasia, but endoscopic biopsy diagnosed cancer in only two of them. CT scans gave no clear evidence of malignancy in any patient, although three scans had nonspecific findings that, in retrospect, probably indicated malignancy. There were no distinguishing manometric findings. CONCLUSIONS: When pseudoachalasia is suspected on the basis of a constellation of findings, such as advanced age, rapid weight loss, and difficulty in passing the endoscope through the gastroesophageal junction of a nondilated esophagus, negative findings on biopsy and CT scans should not lead to a false reassurance of a benign disorder, and repeated biopsy and scans or surgical exploration may lead to the diagnosis of pseudoachalasia.