Understanding the Spatial Clustering of Severe Acute Respiratory Syndrome (SARS) in Hong Kong

We applied cartographic and geostatistical methods in analyzing the patterns of disease spread during the 2003 severe acute respiratory syndrome (SARS) outbreak in Hong Kong using geographic information system (GIS) technology. We analyzed an integrated database that contained clinical and personal details on all 1,755 patients confirmed to have SARS from 15 February to 22 June 2003. Elementary mapping of disease occurrences in space and time simultaneously revealed the geographic extent of spread throughout the territory. Statistical surfaces created by the kernel method confirmed that SARS cases were highly clustered and identified distinct disease “hot spots.” Contextual analysis of mean and standard deviation of different density classes indicated that the period from day 1 (18 February) through day 16 (6 March) was the prodrome of the epidemic, whereas days 86 (15 May) to 106 (4 June) marked the declining phase of the outbreak. Origin-and-destination plots showed the directional bias and radius of spread of superspreading events. Integration of GIS technology into routine field epidemiologic surveillance can offer a real-time quantitative method for identifying and tracking the geospatial spread of infectious diseases, as our experience with SARS has demonstrated

Censoring of patient-held records by doctors

Computer-held information is increasingly shared between general practice and hospitals and with the provisions of the Data Protection Act now in operation, the practical issues of disclosure to patients need to be reviewed. Patients attending diabetic clinics at University Hospital, Nottingham, are routinely issued with a copy of their computerheld record but a previous study showed a high level of censoring by the hospital doctors. This paper reports a review of a sample of 251 censored records, containing 426 problems, whereby the doctors concerned provided reasons for the censoring and restored information they thought suitable. After the review, only 8% of censored problems, that is 1% of all problems, remained censored. An additional 2% of all problems were deleted from the patient's copy at the request of the patient. It is essential that systems which allow censoring of patient records have continuous built-in audit to monitor the reasons for censoring

Community psycho-behavioural surveillance and related impact on outbreak control in Hong Kong and Singapore during the SARS epidemic

Hong Kong Medical Journal15SUPP930-34HKMJ

MEMS resonator tuning using focused ion beam platinum deposition

This paper presents a novel post-fabrication tuning method which changes the resonant frequency of micromechanical beam resonators using Focused Ion Beam (FIB) deposition and removal of platinum. Tuning was achieved by depositing platinum on a 13x5m surface area at the tips of cantilever and the middle sections of bridge resonators in thicknesses ranging from 0.3 to 3.1m. Measurements on both types of resonator structures showed a maximum frequency change of -12% for 2.4 and 3.1m thick deposition. A decrease was observed in the quality (Q) factor due to the damping effect of the platinum material and the increased surface roughness of the resonator. After deposition, the change in resonant frequency was re-adjusted by precise milling of the deposited platinu

SiC cantilever resonators with electrothermal actuation

Cubic SiC cantilever resonators designed for electrothermal actuation are presented. Metal electrodes with both open circuit and short circuit designs have been deposited and patterned on top of the 3C-SiC cantilevers. Pt electrodes on single crystal 3C-SiC cantilevers and NiCr electrodes on poly-crystalline 3C-SiC cantilevers have both been fabricated and tested in order to investigate the material property effect on the performance of the devices. An analytical model has been developed to understand the electrical power distribution in the cantilevers for the different material systems as well as the different metal terminations. Electrothermal actuation of resonance has been successfully achieved in all the fabricated cantilevers. The dynamic performance of the cantilever resonators has been systematically studied including resonance frequencies, amplitude response with voltage and actuation efficiencies. During the discussion of these results, the mechanism of the electrothermal actuation in these devices has been identified which allows actuation frequencies up to 100MHz to be possible

A clinical prediction rule for diagnosing severe acute respiratory syndrome in the emergency department

1. Several features increased the likelihood of severe acute respiratory syndrome (SARS): previous contact with a patient with SARS, fever, myalgia (muscle aches), malaise (feeling unwell), abnormal chest radiograph, and abnormal lymphocyte and low platelet counts. Age older than 65 years or younger than 1 years, sputum production, abdominal pain, sore throat, runny nose, and high neutrophil count decreased the likelihood of SARS. 2. We derived a risk index that used data easily obtained in emergency departments, and identified patients with low and high likelihood of SARS during an outbreak. 3. Study data were obtained by reviewing medical records. Some patients may have had symptoms and findings that were not recorded in the records. Characteristics that identify patients with a high likelihood of SARS may differ in settings that are not large outbreaks