Original Article

SS Chao, KS Loh
Correspondence: Dr Chao Siew Shuen, entv6@nus.edu.sg

ABSTRACT
Introduction Rhinosporidiosis is a rare cause of nasal masses locally, with only two cases reported over a 35-year period.
Methods Four patients with rhinosporidiosis, all from the Indian subcontinent, were managed at our tertiary referral centre over a recent five-year period. They presented with nasal masses and the diagnosis was confirmed by histological examination.
Results All patients were treated by local excision of the nasal masses, and two also received dapsone therapy after surgery. During follow-up, local recurrence was found in two patients, one of whom had received dapsone.
Conclusion With a significant number of foreign workers from endemic regions, this uncommon disease may be observed more frequently in the future. It is thus important to consider the diagnosis of rhinosporidiosis in patients from endemic regions presenting with nasal masses. The mainstay of treatment should be wide surgical excision.

Keywords: dapsone therapy, nasal mass, nasal obstruction, rhinosporidiosis, surgical excision
Singapore Med J 2004; 45(5): 224-226

WYK Hwang, LYA Chai, HJ Ng, YT Goh, PHC Tan
Correspondence: Dr William Hwang Ying Khee, ghehyk@sgh.com.sg

ABSTRACT
Introduction The thrombotic thrombocytopenic purpura-haemolytic uraemic syndromes (TTP-HUS) are uncommon disorders that are fatal if untreated. Therapeutic plasma exchange has resulted in excellent remission and survival rates in this patient population.
Methods We reviewed our experience of therapeutic plasmapheresis for TTP-HUS syndromes for 11 patients who presented in the last five years. Parameters captured included haemoglobin and platelet counts at presentation as well as the number of plasmapheresis sessions and adjunctive treatment given.
Results We found a response rate of 82 percent to plasma exchange, of whom 55 percent attained complete remission. Responses were excellent in the five patients who presented with primary or idiopathic TTP (100 percent response) among whom 80 percent had sustained long term responses. Responses were poor and often unsustained (only one out of six survived) in patients who presented with thrombotic microangiopathies secondary to underlying disorders such as bone marrow transplantation and metastatic carcinoma.
Conclusion Plasmapheresis is mandatory and extremely effective for primary TTP. However, it is at most an adjunct for patients who developed it secondary to an underlying disorder until and if the primary disorder can be successfully treated.

Keywords: therapeutic plasmapheresis, thrombotic thrombocytopenic purpura
Singapore Med J 2004; 45(5): 219-223

H Alfizah, AJ Nordiah, WS Rozaidi
Correspondence: Alfizah Hanafiah, alfizah@mail.hukm.ukm.my

ABSTRACT
Introduction Serratia marcescens is a well-known cause of nosocomial infections and outbreaks, particularly in immunocompromised patients with severe underlying disease. An outbreak due to S. marcescens infection was detected from 13 to 22 February 2001 at the intensive care unit (ICU) of our institution. We used pulsed-field gel electrophoresis (PFGE) typing to analyse the outbreak strains involved.
Methods A total of 25 isolates were included in this study: 12 isolates from infected patients, nine isolates from insulin solution, one isolate from sedative solution (midazolam and morphine infusion) and one isolate from frusemide solution. Two isolates from other wards which were epidemiologically-unrelated were also included.
Results The S. marcescens from patients, insulin solution and sedative solution showed an identical PFGE fingerprint pattern. The isolate from the frusemide solution had a closely-related PFGE pattern to the outbreak strain with one band difference. Attempts were made in the present study to identify the environmental reservoir of S. marcescens during the outbreak. We found that the insulin and sedative solutions used by the patients were contaminated with S. marcescens which was proven to be the source of the outbreak.
Conclusion Using PFGE, we showed that the outbreak in the ICU of our hospital was due to the clonal spread of a single strain of S. marcescens.

Keywords: intensive care unit, nosocomial infection, pulsed-field gel electrophoresis, Serratia marcescens
Singapore Med J 2004; 45(5): 214-218

SC Emmanuel, HP Phua, PY Cheong
Correspondence: Dr S C Emmanuel, Shanta_EMMANUEL@nhgp.com.sg

ABSTRACT
Introduction The 2001 survey on primary medical care was undertaken to compare updated primary healthcare practices such as workload and working hours in the public and private sectors; determine private and public sector market shares in primary medical care provision; and gather the biographical profile and morbidity profile of patients seeking primary medical care from both sectors in Singapore. This is the third survey in its series, the earlier two having been carried out in 1988 and 1993, respectively.
Methods The survey questionnaire was sent out to all the 1480 family doctors in private primary health outpatient practice, the 89 community-based paediatricians in the private sector who were registered with the Singapore Medical Council and also to all 152 family doctors working in the public sector primary medical care clinics. The latter comprised the polyclinics under the two health clusters in Singapore, namely the Singapore Health Services and National Healthcare Group, and to a very much smaller extent, the School Health Service's (SHS) outpatient clinics. The survey was conducted on 21 August 2001, and repeated on 25 September 2001 to enable those who had not responded to the original survey date to participate. Subjects consisted of all outpatients who sought treatment at the private family practice clinics (including the clinics of the community-based paediatricians), and the public sector primary medical care clinics, on the survey day.
Results The response rate from the family doctors in private practice was 36 percent. Owing to the structured administrative organisation of the polyclinics and SHS outpatient clinics, all returns were completed and submitted to the respective headquarters. Response from the community-based paediatricians was poor, so their findings were omitted in the survey analysis. The survey showed that the average daily patient-load of a family doctor in private practice was 33 patients per day, which was lower than the 40 patients a day recorded in 1993. The average working hours of each of these private practitioners was 7.6 hours per day. Family doctors in public sector primary medical care clinics were responsible for 16.6 percent of the patient-load for primary medical care in Singapore while the remaining 83.4 percent was provided by family doctors in private practice. Singaporeans made approximately 4.4 visits to a family doctor in 2001, which was lower than the 5.0 visits ascertained in 1993. Chronic medical conditions seen by family doctors as a whole, increased from 29.2 percent in 1993 to 34.3 percent in 2001. Upper respiratory tract infections and hypertension were the two leading disease conditions seen at both private and public sector primary medical care clinics in 2001. The load of hypertension managed at primary medical care clinics had notably increased.
Conclusion The public sector share of outpatient load at 17 percent in 2001 is well within the 25 percent level set in the Government's 1993 White Paper on Affordable Healthcare. The private sector remains the main provider of primary medical care in Singapore, serving 83 percent of the population. The average workload for each family doctor in private practice had dropped from 40 to 33 patients a day between 1993 and 2001. There had been a notable growth in family doctors working in the private sector over this period. Both sectors saw an increase in the chronic disease load that they managed.

Keywords: family doctors, primary medical care, private primary medical practice, public primary medical practice
Singapore Med J 2004; 45(5): 199-213

KDKY Choy, HS Lee, CH Tan
Correspondence: Dr Choy Kwok Yin Kenneth David, Kenneth_CHOY@mom.gov.sg

ABSTRACT
Introduction To illustrate the lead hazard in the ceramics art industry and the importance of blood lead monitoring and suspension of workers with high blood lead levels.
Methods Interviews were conducted for workers exposed to the lead hazard from a factory manufacturing decorative ceramic tiles. Serial blood lead levels were taken and measurements of lead-in-air and lead in the bulk samples were conducted.
Results High blood lead levels were observed in four out of 12 workers. Three workers were suspended from further lead exposure and one left the factory. These workers were not aware of the hazards of lead and the importance of good personal hygiene. They were educated on the hazards of lead, the importance of good personal hygiene practices and on the use of the appropriate personal protective equipment. There was an improvement in overall blood lead results in the subsequent months.
Conclusion Lead hazard is present in the ceramics art industry and ingestion is probably an important route of absorption. The monitoring of blood lead levels was useful to identify and follow-up workers with high blood lead levels. Suspension of workers from further lead exposure was effective in decreasing the blood lead levels of the workers.

Keywords: blood lead monitoring, ceramic tiles, ingestion, serial blood lead levels
Singapore Med J 2004; 45(4): 176-179

BD Aziah, BN Rusli, T Winn, L Naing, MA Tengku
Correspondence: Prof Rusli bin Nordin, rusli@kb.usm.my

ABSTRACT
Introduction Several sources of job stress exist. Some of these stressors are intrinsic to the job, while some are related to psychosocial and other factors.
Methods A cross-sectional study of the prevalence and risk factors of job strain in 84 laboratory technicians in Hospital Universiti Sains Malaysia (HUSM) (response rate 82.4 percent) was conducted between September 2001 and February 2002. A Malay version of the validated Karasek's Job Content Questionnaire was used as the research instrument in this study. There were five scales in the questionnaire. Two scales were used to define job strain, namely: decision latitude and psychological demands.
Results The prevalence of high job strain in laboratory technicians in HUSM was 33.3 percent. Job insecurity (adjusted OR 2.4; 95 percent CI 1.2-5.7), physical exertion (adjusted OR 1.7; 95 percent CI 1.1-2.9), and total psychological stressors (adjusted OR 3.6; 95 percent CI 1.8-7.1) were significantly associated with job strain.
Conclusion A high proportion of laboratory technicians in HUSM experienced high job strain and psychosocial factors in the workplace posed significant risks of job strain in these workers.

Keywords: Job Content Questionnaire, job strain, risk factors, laboratory technicians, psychosocial factors
Singapore Med J 2004; 45(4): 170-175

JJ Lee, EY Yap
Correspondence: Dr Lee Jong Jian, jongjian@hotmail.com

ABSTRACT
Introduction Optociliary shunt vessels is classically described to be associated with optic nerve sheath meningioma, with the triad symptoms of optociliary veins, disc pallor and visual loss. Other clinical settings include retinal vein occlusion, chronic glaucoma, meningioma, and rarely as a congenital form. We report an interesting case series of three patients with diabetes mellitus presenting with optociliary shunts.
Methods Patients who underwent diabetic retinopathy screening were referred to the eye clinic for abnormal findings. Between 2000 and 2001, out of a total of 3,360 patients, three diabetic patients with optociliary shunt vessels were found (0.1 percent). Optociliary shunt vessels were documented with fundus photography and fundal fluorescein angiography.
Results All three patients had bilateral mild nonproliferative diabetic retinopathy with one having, in addition, bilateral diabetic maculopathy. Fluorescein angiography showed classical features of acquired optociliary shunts with no leakage. Systemic review did not show any secondary cause of the optociliary shunts.
Conclusion Our case series showed that optociliary veins can be associated with diabetes mellitus. The authors postulate that it may be due to venous insufficiency secondary to the process of diabetic microangiopathy and venous stasis.

Keywords: diabetes mellitus, diabetic retinopathy, fluoresein angiography, optociliary shunts
Singapore Med J 2004; 45(4): 166-169

AF Low, WL Ng, YT Lim, TC Yeo
Correspondence: Dr Adrian F Low, mdclowa@nus.edu.sg

ABSTRACT
Introduction There is currently limited data on the prognostic value of a normal dobutamine stress echocardiogram (DSE) in patients with intermediate to high cardiovascular risk. The impact of diabetes mellitus, recently recognised as a cardiovascular risk-equivalent, has not been previously evaluated. This study aims to determine the prognostic value of a normal DSE in these patients.
Methods The study population includes all patients with two cardiovascular risk factors or diabetes mellitus and a normal DSE (baseline and peak stress) with three months follow-up. A total of 122 patients (47 females, 75 males; mean age 59.6 years) were recruited. Impact of diabetes mellitus on subsequent cardiovascular events was determined.
Results Diabetes mellitus was present in 32.8 percent, hypertension in 72.1 percent, smoking in 27.0 percent, family history of premature coronary artery disease in 15.6 percent, and hypercholesterolemia in 66.4 percent. On follow-up until 6.4 years (mean 4.1 years), there were four myocardial infarctions (0.8 percent per patient/year) and five revascularisation procedures (1.0 percent per patient/year). The majority of adverse events occurred among patients with diabetes mellitus (three out of four myocardial infarctions; four out of five revascularisations). Diabetes mellitus independently predicted subsequent cardiac events on both univariate and multivariate analyses (p value is equal to 0.015 and 0.011, respectively). Presence of diabetes mellitus also conferred a worse outcome on survival analysis (p value is equivalent to 0.0046).
Conclusion The presence of diabetes mellitus adversely affects clinical outcome despite a normal DSE. Patients without diabetes mellitus, but with intermediate to high cardiovascular risk, and a normal DSE have a better medium term outcome.

Keywords: cardiovascular disease, diabetes mellitus, echocardiogram, dobutamine stress echocardiography, stress testing
Singapore Med J 2004; 45(4): 161-165

CY Hong, KS Chia, K Hughes, SL Ling
Correspondence: Dr Ching-Ye Hong, hong_ching_ye@hpb.gov.sg

ABSTRACT
Introduction Ethnic differences exist in patients with diabetes mellitus. Not much is known about such differences in Asian populations. The aim of the study was to determine ethnic differences among Chinese, Malay and Indian patients with type 2 diabetes mellitus in Singapore.
Methods The study design was cross-sectional, involving 967 patients who were attending follow-up care for type 2 diabetes mellitus at a primary care clinic. Data collection was by patient interview, examination, and from case records. Blood and urine samples were collected for analysis of indicators of diabetic control and albuminuria.
Results Malays had the highest mean body mass index (BMI) after controlling for age, gender, duration of diabetes and exercise status. Adjusted mean BMI for Malays was 27.4kg per square metres, Indians 25.7kg per square metres, Chinese 24.9kg per square metres, with the p value being less than 0.01. HbA1c levels were highest among Indians after controlling for age, duration of diabetes, body mass index and treatment. Adjusted mean HbA1c for Indians was 8.3 percent, Malays 8.0 percent, and Chinese 7.7 percent, with the p value being less than 0.01. Compared with Chinese, Indians were more likely to have a positive family history of diabetes (prevalence rate ratio (PRR) of 1.3, 95 percent confidence interval (CI) of 1.0 to 1.7), but were less likely to have associated hypertension (PRR of 0.7, 95 percent CI of 0.5 to 1.0) and microalbuminuria and macroalbuminuria (PRR of 0.6, 95 percent CI of 0.4 to 1.0).
Conclusion Ethnic differences exist with regard to BMI, diabetic control as reflected by HbA1c levels, family history of diabetes, presence of associated hypertension, and severity of albuminuria. Indians, while having poorer control of diabetes, are less prone to hypertension and renal complications than Chinese.

Keywords: body mass index, diabetes mellitus, hypertension, family history, albuminuria
Singapore Med J 2004; 45(4): 154-160

N Ukarapol, N Lertprasertsuk, L Wongsawasdi
Correspondence: Dr Nuthapong Ukarapol, nukarapo@mail.med.cmu.ac.th

ABSTRACT
Introduction To study the utility of upper gastrointestinal endoscopy with biopsy in the evaluation of children with clinically-significant recurrent abdominal pain.
Methods Over a three-month period, children with three or more episodes of upper abdominal pain that was severe enough to impair their normal activity and required medical attention were included in the study. After complete history, physical examination and basic investigations, upper gastrointestinal endoscopy with biopsy was performed in all patients.
Results Thirty-eight children were enrolled. Their average age was 10.5 years and 21 were female. Organic causes were identified in 44.7 percent of the cases, with Helicobacter pylori gastritis being the most common diagnosis (28.9 percent). No specific dyspeptic symptom was significantly associated with either organic cause of recurrent abdominal pain or Helicobacter pylori infection. Antral nodularity was the only endoscopic finding significantly associated with Helicobacter pylori infection (sensitivity 63.4 percent, specificity 85.2 percent). All patients improved after specific therapy was instituted.
Conclusion The organic causes of recurrent abdominal pain in children have been increasingly identified in our hospital, a tertiary care centre in Northern Thailand. One of the most common causes found in this study was Helicobacter pylori infection. Upper endoscopy was very helpful in identifying the underlying pathology.

Keywords: abdominal pain, children, endoscopy, Helicobacter pylori, recurrent abdominal pain
Singapore Med J 2004; 45(3): 121-124