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Background and Purpose: An epidemic of suspected Japanese encephalitis occurred in Malaysia in 1998-1999 among pig farmers. In neighboring Singapore, an outbreak occurred among pig slaughterhouse workers. It was subsequently established that the causative agent in the outbreak was not the Japanese encephalitis virus but a previously unknown Hendra-like paramyxovirus named Nipah virus., Methods: The brain MR images of eight patients with Nipah virus infection were reviewed. All patients tested negative for acute Japanese encephalitis virus. Seven patients had contrast-enhanced studies and six had diffusion-weighted examinations., Results: All patients had multiple small bilateral foci of T2 prolongation within the subcortical and deep white matter. The periventricular region and corpus callosum were also involved. In addition to white matter disease, five patients had cortical lesions, three had brain stem involvement, and a single thalamic lesion was detected in one patient. All lesions were less than 1 cm in maximum diameter. In five patients, diffusion-weighted images showed increased signal. Four patients had leptomeningeal enhancement and four had enhancement of parenchymal lesions., Conclusion: The brain MR findings in patients infected with the newly discovered Nipah paramyxovirus are different from those of patients with Japanese encephalitis. In a zoonotic epidemic, this striking difference in the appearance and distribution of lesions is useful in differentiating these diseases. Diffusion-weighted imaging was advantageous in increasing lesion conspicuity.

Objective: To determine the pathogenesis of catheter-associated urinary tract infection (CAUTI) and the relative importance of each of the possible mechanisms of entry of infecting microorganisms to the catheterized urinary tract., Material and Methods: We conducted a prospective study of 1,497 newly catheterized patients. Paired quantitative urine cultures were obtained daily, from the catheter specimen port and from the collection bag, using a technique that could detect 1 colony-forming unit/mL. We assumed that with extraluminal infections, caused by microorganisms ascending from the perineum in the mucous film contiguous to the external surface of the catheter, the organisms would be detected first in bladder urine or in far higher concentrations in urine from the specimen port than from the collection bag. With intraluminal CAUTIs, caused by microorganisms gaining access to the catheter lumen because of failure of closed drainage or contamination of collection bag urine, the organisms would be detected first or in far larger numbers in a collection bag specimen., Results: The probable mechanism of infection could be determined for 173 of 250 organisms (69.2 %) identified in 235 new-onset CAUTIs. Among these 173 cases, 115 (66%) were extraluminally acquired, and 58 (34%) were derived from intraluminal contaminants. For these determinable cases, CAUTIs caused by gram-positive cocci (enterococci and staphylococci) and yeasts were far more likely to be extraluminally acquired (extraluminal:intraluminal, 2.9) than were gram-negative bacilli, which caused CAUTIs by both routes equally (extraluminal: intraluminal, 1.2; P = 0.007). Surprisingly, no significant differences were noted in pathogenetic mechanisms between men and women., Conclusion: We conclude that, in both men and women, CAUTIs occur by both extraluminal and intraluminal portals of entry but derive preponderantly from organisms that gain access extraluminally. Strategies for prevention of CAUTIs must focus on new technologies to prevent access of organisms by all possible routes.

Streptococcus suis infection, an important zoonotic occupational disease in humans, is associated with meningitis, arthritis, and perceptive deafness. We report a case of severe S. suis infection in a previously healthy man who developed purpura fulminans and rhabdomyolysis, complications not previously reported with this disease.

Over a period of 27 months, 32 patients aged 40 and below were admitted for acute myocardial infarction. Twenty-nine had coronary angiography with a mean of 15.7 +/- 10.0 days following infarction. Fourteen patients had single vessel, 10 multi-vessel and 5 had only minor coronary disease. Disease in the left anterior descending (LAD) artery was more common than in the circumflex or right coronary artery (RCA), but myocardial infarction occurred with near equal frequency in both the LAD and RCA territories. Only 2 infarct-related vessels were collateralized. Spontaneous coronary dissection was detected in 2 patients. The left ventricular function was significantly impaired in about half of the patients.

A retrospective analysis was carried out on all patients aged 40 years and below with acute myocardial infarction admitted to the coronary care unit (CCU) at the National University Hospital (NUH). We found that most came early direct to hospital, more than half of those eligible received thrombolysis and there was a low incidence of complications. Compared to the Singapore population, Indians in the group were over-represented. The most common coronary risk factor was smoking. A majority had elevated serum cholesterol level. These observations may provide some insight for the primary prevention of premature coronary artery disease in young people in Singapore.

Down syndrome has long been associated with a variety of autoimmune conditions. A significant link has also been described between Down syndrome and autoimmune thyroid disease, usually hypothyroidism. We report two cases of Down syndrome with Graves disease both with significantly elevated titres of thyrotropin receptor antibody and the presence of the HLA Bw46. We also comment on the problems in diagnosis and management of such patients.

A patient who had prolonged hyperparathyroidism with extensive bone involvement developed delayed post-surgical complications of pseudogout and the hungry bone syndrome with persistent hypocalcaemia and hypomagnesaemia. Although urinary calcium excretion was appropriate for the hypocalcaemia, there was severe excessive renal loss of magnesium despite the hypomagnesaemia. Renal magnesium excretion returned to normal only after correction of the hypocalcaemia. Hypermagnesuria may be an important cause of resistant hypomagnesaemia after parathyroid surgery.