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Biomedical subjects

Paul A Tambyah

Publications and source records attributed to Paul A Tambyah.

14 recordsLinked to original sources
PubMed2006

An outbreak of Fusarium keratitis associated with contact lens wear in Singapore.

CONTEXT: Fungal keratitis is a potentially blinding condition that is rarely seen with contact lens wear. OBJECTIVE: To describe a nationwide outbreak of fungal keratitis caused by Fusarium species among contact lens wearers in Singapore. DESIGN, SETTING, AND PATIENTS: Nationwide, hospital-based case series. All cases of fungal keratitis among contact lens wearers in all ophthalmology departments in Singapore were reviewed along with the charts of all contact lens wearers with culture-proven fungal keratitis from March 2005 through May 2006. A standardized telephone interview was conducted to obtain additional clinical information. MAIN OUTCOME MEASURE: Diagnosis of Fusarium keratitis associated with contact lens wear. RESULTS: During the study period, 66 patients (68 affected eyes) were diagnosed with Fusarium keratitis associated with contact lens wear; the estimated annual national incidence is 2.35 cases per 10,000 contact lens wearers (95% confidence interval, 0.62-7.22). Patients ranged in age from 13 to 44 years (mean [SD], 27.1 [8.4] years), of which 32 (48.5%) were men. The vast majority (65 patients; 98.5%) wore soft, disposable contact lenses; 62 patients (93.9%) reported using 1 brand of contact lens cleaning solution (ReNu, Bausch & Lomb, Rochester, NY), including 42 patients (63.6%) who recalled using ReNu with MoistureLoc. Most patients (81.8%) reported poor contact lens hygiene practices, including overnight use of daily wear contact lenses (19.7%), and use of contact lenses past the replacement date (43.9%). The final best-corrected visual acuity ranged from 20/20 to 20/80. Five patients (5 eyes; 7.4%) required emergency therapeutic or tectonic corneal transplantation. CONCLUSIONS: A new and evolving epidemic of Fusarium keratitis associated with contact lens wear was found in Singapore. Physicians and eye care practitioners worldwide need to be aware of the likelihood of similar outbreaks emerging among contact lens wearers.

Adolescent↗
PubMed2004

Mild illness associated with severe acute respiratory syndrome coronavirus infection: lessons from a prospective seroepidemiologic study of health-care workers in a teaching hospital in Singapore.

BACKGROUND: Severe acute respiratory syndrome (SARS) is a newly recognized infectious disease that has recently emerged in East Asia and North America. Although the clinical features of acute infection have been well described, mildly symptomatic or asymptomatic infections have not been well characterized. OBJECTIVE: To assess the spectrum of illness in health-care workers (HCWs). METHODS: A prospective seroepidemiologic cohort study was conducted on 372 HCWs in a large teaching hospital in Singapore who were both exposed and not exposed to patients with SARS. Participating HCWs completed a questionnaire and provided paired serum samples, which were analyzed by 2 different laboratories blinded to clinical data, by use of an enzyme-linked immunosorbent assay based on a protocol developed by the Centers for Disease Control and Prevention and a dot-blot immunoassay, with confirmation by a viral neutralization assay. RESULTS: A total of 21 patients with SARS were treated at our hospital. They were associated with transmission to 14 staff members, patients, and visitors in our hospital. Of the 372 HCWs participating in the present study, 8 were found to have positive antibodies to the SARS coronavirus in both samples by use of both test methods, and 6 had pneumonia and had been hospitalized for either probable or suspected SARS infection, whereas 2 had fever but did not have changes on chest radiographs. All seropositive HCWs had been exposed either directly or indirectly to patients with SARS. No asymptomatic, nonexposed staff members were found to be seropositive. There was a trend towards protection for HCWs who, while fully protected, had had contact with patients with SARS. CONCLUSIONS: Although the majority of cases of SARS are associated with pneumonia, a small number of mildly symptomatic individuals do seroconvert. HCWs who are exposed to patients with SARS can be infected with SARS, regardless of the intensity of exposure. This has implications for surveillance and infection control planning, in the event that SARS returns next winter.

Adult↗
PubMed2004

Catheter-associated urinary tract infections: diagnosis and prophylaxis.

Catheter-associated urinary tract infections (CAUTI) are the commonest nosocomial infections worldwide. While they are often asymptomatic and frequently cost less than nosocomial surgical site infections or nosocomial pneumonia, they are major reservoirs of antimicrobial resistant pathogens. Numerous strategies have been devised in an attempt to reduce the incidence of CAUTI but few have proven effective. Novel technologies such as the potential use of antiseptic or antimicrobial coatings on catheters hold promise for possibly reducing these infections in the fight against antimicrobial resistance.

Anti-Infective Agents, Local↗
PubMed2004

Severe acute respiratory syndrome from the trenches, at a Singapore university hospital.

The epidemiology and virology of severe acute respiratory syndrome (SARS) have been written about many times and several guidelines on the infection control and public health measures believed necessary to control the spread of the virus have been published. However, there have been few reports of the problems that infectious disease clinicians encounter when dealing with the protean manifestations of this pathogen. This is a qualitative account of some of the issues faced by an infectious disease physician when identifying and treating patients with SARS as well as protecting other healthcare workers and patients, including: identification of the chain of contagion, early recognition of the disease in the absence of a reliable and rapid diagnostic test, appropriate use of personal protective equipment, and the use of isolation to prevent super-spreading events. Many issues need to be addressed if clinicians are to be able to manage the virus should it reappear.

Adult↗
PubMed2004

Nosocomial infection with vancomycin-dependent enterococci.

We report three patients infected with unique strains of vancomycin-dependent enterococci. Two were first infected by genetically identical strains of vancomycin-resistant enterococci (VRE). All three patients had much greater exposure to vancomycin and third-generation cephalosporins than did two control groups (patients infected with VRE and hospitalized patients without enterococcal infections). While antimicrobial pressure promotes nosocomial colonization by VRE, prolonged exposure to vancomycin may foster the transition from vancomycin resistance to dependence.

Anti-Bacterial Agents↗
PubMed2003

Community-acquired methicillin-resistant Staphylococcus aureus infection in Singapore is usually "healthcare associated".

OBJECTIVE: To assess the frequency of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections. SETTING: A teaching hospital in Singapore. METHODS: Prospectively collected surveillance data were reviewed during a 1-year period to determine the extent and origin of community-acquired MRSA infections. RESULTS: Whereas 32% of 383 MRSA infections were detected less than 48 hours after hospital admission and would, by convention, be classified as "community acquired," all but one of these were among patients who had been exposed to outpatient centers including dialysis or chemotherapy clinics, visiting nurses, community hospitals, or all three. CONCLUSIONS: With health care increasingly being delivered in an outpatient setting, community-acquired MRSA infections are often acquired in hospital-related sites and most may be more accurately described as "healthcare acquired." Infection control measures need to move beyond the traditional paradigm of acute care hospitals to effectively control the spread of resistant pathogens.

Community-Acquired Infections↗
PubMed2002

The direct costs of nosocomial catheter-associated urinary tract infection in the era of managed care.

OBJECTIVE: To determine the additional direct costs of hospitalization attributable to catheter-associated urinary tract infection (CAUTI) in 1,497 newly catheterized patients. DESIGN: Prospective observational and laboratory study. SETTING: University hospital. METHODS: Data were collected on risk factors for CAUTI (defined as > 10(3) colony-forming units [CFU]/mL), severity of illness, and diagnostic and therapeutic interventions in consenting newly catheterized patients. Daily urine cultures were obtained from each newly catheterized patient, but the results of these cultures were not revealed to his or her physician. During the study, one of the investigators (DGM) reviewed each patient's record and made a judgment as to which of the diagnostic tests and treatments ordered and what incremental length of stay could reasonably be ascribed to his or her CAUTI. The total hospital costs for each patient were also obtained. RESULTS: Overall, 235 patients acquired CAUTIs during the study; most of the CAUTIs were completely asymptomatic, and only 52% were diagnosed by the patients' physicians using the hospital laboratory. Only 1 patient with a CAUTI had a secondary bloodstream infection. Thirty-three (13%) of the CAUTIs were caused by Escherichia coli; 63 (25%) by Klebsiella, Enterobacter, Citrobacter, Pseudomonas aeruginosa, or other antibiotic-resistant, gram-negative bacilli; 87 (35%) by enterococci or staphylococci; and 67 (27%) by Candida species. The 123 CAUTIs diagnosed by the hospital laboratory were judged to have been responsible for an additional $20,662 in extra costs of diagnostic tests and $35,872 in extra medication costs, a mean of $589 (median, $356) per CAUTI. CAUTIs caused by E. coli cost considerably less than infections caused by other gram-negative bacilli ($363.3 +/- $228.2 vs $690.4 +/- $783.7; P = .02) or yeasts ($821.2 +/- $2,169.9). There were less striking differences in the costs per CAUTI caused by staphylococci or enterococci ($387.1 +/- $434.8). CONCLUSIONS: The extra direct costs associated with nosocomial CAUTI found in this prospective study, which was done in the era of managed care during the late 1990s, are substantially lower than those reported in the largest comparable studies done more than 15 years ago, most of which were retrospective, reflecting the powerful impact of cost-containment measures that are now implemented in managed care.

Adult↗
PubMed2002

Nipah virus encephalitis: serial MR study of an emerging disease.

PURPOSE: To report the serial magnetic resonance (MR) imaging findings of the Nipah virus. MATERIALS AND METHODS: Twelve patients underwent serial MR imaging. Eight patients were examined at the outbreak; 11, at 1 month; and seven, at 6 months. Contrast material-enhanced MR images, diffusion-weighted images, and single-voxel proton MR spectroscopic images were reviewed. Clinical and neurologic assessment, as well as analysis of the size, location, and appearance of brain lesions on MR images, were performed. RESULTS: During the outbreak, all eight patients had multiple small foci of high signal intensity within the white matter on T2-weighted images. In six patients, cortical and brain stem lesions were also detected, and five patients had diffusion-weighted MR imaging-depicted hyperintensities. One month after the outbreak, five patients had widespread tiny foci of high signal intensity on T1-weighted images, particularly in the cerebral cortex. Diffusion-weighted images showed decreased prominence or disappearance of lesions over time. There was no evidence of progression or relapse of the lesions at 6-month follow-up. MR spectroscopy depicted reduction in N-acetylaspartate-to-creatine ratio and elevation of choline-to-creatine ratios. CONCLUSION: The Nipah virus has findings unlike other viral encephalitides: small lesions that are primarily within the white matter, with transient punctate cortical hyperintensities on T1-weighted images.

Adult↗