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S K Chew

Publications and source records attributed to S K Chew.

At least 19 recordsLinked to original sources
PubMed1995

A national computer-based surveillance system for tuberculosis notification in Singapore.

SETTING: The notification rate of tuberculosis (TB) among residents in Singapore has been declining at a mean rate of 5.6% per annum, from 307 cases per 100,000 population in 1960 to 54 cases per 100,000 population in 1992. A National TB Notification Registry was set up in 1958 using a manual card system, and was captured into a computer database from 1986. OBJECTIVE: To monitor epidemiological trends of TB in Singapore with more speed, versatility and analytical capabilities, a new microcomputer-based surveillance system was developed in 1993. DESIGN: The main software programmes used in this system were DBase IV (version 1.5) and Epi Info (version 5). These versions could use base memory interchangeably and were therefore incorporated into a single application DBase programme. Security features were incorporated into the programme. The TB database was linked to the National HIV Notification Registry to enhance surveillance of combined TB and human immunodeficiency virus infection (HIV). RESULTS: The system was able to track notifications and TB culture results, address letters and analyze data and enabled prompt dissemination of information. CONCLUSION: The authors believe that this system would enhance surveillance and provide timely information for national TB control programmes. However, the effectiveness of this system is dependent on an established notification structure with notifications for tuberculosis of sufficient completeness.

Database Management Systems↗
PubMed1995

Prevalence of hepatitis B virus (HBV) infection in Singapore men with sexually transmitted diseases and HIV infection: role of sexual transmission in a city state with intermediate HBV endemicity.

STUDY OBJECTIVES: To describe the prevalence of hepatitis B virus (HBV) infection in patients with sexually transmitted diseases (STD) and human immunodeficiency virus (HIV) infection, and to determine the role of sexual transmission of HBV infection in Singapore. DESIGN: A cross sectional study of all consecutive men presenting with a new episode of STD at a government outpatient clinic and all men with HIV infection on routine follow up at a government hospital. The prevalence of various HBV markers was compared with that of healthy males aged 15 years and above (controls). SETTING: Singapore, a city state of intermediate HBV endemicity. SUBJECTS: These comprised 497 STD patients, 47 HIV infected patients, and 418 controls. MAIN RESULTS: The overall seroprevalences of HBV infection in STD patients, HIV infected patients, and control subjects were 41.2%, 61.7%, and 33.3%, respectively (p < 0.001). The seroprevalences of hepatitis B surface antigen (6.2%, 8.5%, and 4.5%, respectively) were comparable in the three groups. Using stepwise logistic regression analysis, the adjusted seroprevalences of HBV infection in STD and HIV infected patients were respectively 2.4 times (95% confidence interval (CI), 1.7, 3.3) and 3.3 times (95% CI 1.7, 6.3) higher than in controls. HBV infection rates were higher among Chinese (odds ratio (OR), 1.9; 95% CI 1.6, 3.4) than non-Chinese, and among those aged 25-34 years (OR 2.4; 95% CI 1.6, 3.4), 35-44 years (OR 3.9; 95% CI 2.5, 5.9), and 45+ years (OR 6.2; 95% CI 3.8, 10.2) than in those aged 15-24 years. Sex related factors significantly associated with higher infection rates, independent of age and ethnic group, were reactive VDRL test (OR 2.4; 95% CI 1.2, 4.7), participation in anal intercourse (OR 2.3; 95% CI 1.2, 4.3), and having 10 or more lifetime sexual partners (OR 1.5; 95% CI, 1.0, 2.1). CONCLUSION: The importance of sexual transmission of HBV in an area of intermediate HBV endemicity was confirmed. Patients attending STD clinics should be routinely screened for HBV markers and those found to be seronegative should be strongly advised to be immunised against this virus.

Adolescent↗
PubMed1995

A descriptive profile and the immune status of some hospitalised patients with measles.

The incidence of measles in Singapore has declined with the introduction of measles vaccination in 1976. However, a progressive increase in notified measles cases has occurred since 1990. To characterise the current profile of hospitalised patients with measles, particularly their measles immunity status, we analysed 46 cases over a period of 3 months. The majority (69.6%) were school-going children (aged 5-19 years). Of the 25 patients (54.3%) classified as preventable by immunisation according to the current strategy, 68% were school-age persons. Five previously vaccinated patients had measles enzyme immunoassay immunoglobulin M and immunoglobulin G antibodies present. The occurrence of preventable cases among school-age children indicates that the implementation of the current immunisation programme should be improved.

Adolescent↗
PubMed1995

Multidrug-resistant tuberculosis.

In 1993, the World Health Organization declared tuberculosis a global emergency. Tuberculosis is the leading cause of death attributable to a single infectious pathogen. One-third of the world's population are at risk of developing the disease. In countries confronted with the human immunodeficiency virus (HIV) epidemic, the overlap of these two populations leads to a rapid acceleration of active tuberculosis and of the emergence of multidrug-resistant tuberculosis. Multidrug-resistant tuberculosis is defined as isolates resistant to both isoniazid and rifampicin with or without resistance to other antituberculosis drugs. In the United States, outbreaks of multidrug-resistant tuberculosis have been reported in patients with HIV infection and acquired immunodeficiency syndrome (AIDS) as well as HIV sero-negative patients. These reports have caused great concern owing to the very high case-fatality rate. The treatment outcome of multidrug-resistant tuberculosis is poor. The use of second-line drugs is frequently associated with toxicity and intolerance. Patients require admission to hospitals at the beginning of treatment and adjunctive resectional surgery should be considered when the sputum does not convert after 4 months of therapy. The incidence of multidrug-resistant tuberculosis among Singapore residents remains low. Organisms resistant to one drug occurred in 3.8% of newly diagnosed tuberculosis cases with positive culture and 8.7% of relapsed tuberculosis cases with positive cultures. Organisms resistant to two or more drugs occurred in 1.6% of newly diagnosed culture positive tuberculosis cases and 4.6% of relapsed cases where cultures were positive. This is the result of vigilant surveillance, effective treatment including supervised chemotherapy and close monitoring for non-compliance.

Humans↗
PubMed1995

Oral acyclovir in the treatment of adult varicella.

An open study was conducted to evaluate the efficacy of oral acyclovir in a group of 295 Singapore Armed Forces male servicemen. The 148 patients who were willing to take acyclovir were given 800 mg orally five times per day for seven days. The other 147 who refused to take acyclovir were monitored as a control group. Each of these groups was further classified into two groups. Group A patients presented with rash within 24 hours of rash onset and Group B presented between 24 and 72 hours. Daily lesion counts, temperature, pruritus scores and laboratory tests were used to monitor disease progression. Early acyclovir intervention (Group A) reduced the time to 100% crusting from 7.19 to 5.71 days (P = 0.0001), decreased the maximum number of all lesions by 26% (P = 0.03) and the maximum number of vesicular lesions by 45% (P = 0.0004). Late therapy (Group B) was effective in reducing the maximum number of vesicular lesions by 38% (P = 0.003). The number of patients requiring antibiotics for suspected secondary skin infection, the duration of fever and paracetamol consumption were significantly reduced in both the early and late intervention groups. However, there were no effects in minimizing pruritus in either group. Serious complications such as pneumonia, encephalitis or death were not observed in this study. The most common adverse effect of acyclovir was mild diarrhoea occurring in 35% of patients treated with the drug. We conclude that early treatment with acyclovir was beneficial whereas late therapy had limited effect in reducing the severity of cutaneous lesions in patients with varicella.

Acyclovir↗
PubMed1995

A computer-based surveillance system for human immunodeficiency virus infection in Singapore.

The first case of the human immunodeficiency virus (HIV) infection was detected in Singapore in 1985 and the first case of the acquired immunodeficiency syndrome (AIDS) in 1986. Since then, the number of infections had increased. By the end of 1993, there were 222 residents with HIV infection, including 75 cases of AIDS. In view of the rapidly increasing magnitude of HIV infection, a microcomputer-based surveillance system was designed and developed in 1992 to better monitor epidemiological trends of HIV infection in Singapore. OBJECTIVE--The objective was to define a composite model of a successful HIV and AIDS registry that included: (a) patient data forms, (b) patient's contact data forms, (c) data analysis, and (d) report generation. METHODOLOGY--An IBM-compatible desk-top microcomputer was used for the project. The main software used for computer programming and data analysis were DBase IV (Version 1.5) and Epi Info (Version 5.0), respectively. Security features were incorporated into the programme to ensure confidentiality of information and that only authorized personnel could gain access to the programme. MAIN FINDINGS--The system functioned as the National HIV Notification Registry and was able to track notifications, analyse data and enabled prompt dissemination of information. The system was also linked to another database system for tuberculosis to enhance surveillance of both HIV infection and tuberculosis. CONCLUSION--The authors believe that this system would enhance surveillance and provide timely information for national AIDS control programmes. However, the effectiveness of this computer-based surveillance system is dependent on an established notification structure with notifications of sufficient completeness for both HIV infection and AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Malaria: prophylaxis and therapy.

Malaria remains a significant cause of morbidity and mortality in many regions of the world. In Singapore, an average of 200 cases of malaria have been reported annually, the majority of which are imported cases. Malaria eradication is a goal that may not be achieved. A more realistic aim is to educate and protect individual travellers. This paper attempts to summarise various therapeutic options including the use of monotherapy and combination therapy. The decision on therapy depends on several factors, such as the Plasmodium species, risk of transmission of the resistant parasite and the severity of infection. So far, none of the chemoprophylactic regimens available can provide an absolute protection from malaria transmission. Therefore, one needs to assess the risk of transmission against the potential risk of adverse drug reaction. Complications of anti-malaria drugs may range from minor cutaneous manifestations to death. General measures to prevent vector transmission of the disease should be emphasised while awaiting the development of an effective malaria vaccine.

Animals↗
PubMed1994

Multidrug-resistant typhoid fever in Singapore.

A study was conducted to determine the clinical and epidemiological characteristics of multidrug-resistant (MDR) typhoid fever in Singapore. Twenty-one of 121 patients with typhoid fever had MDR typhoid fever after recent travel to the Indian subcontinent. Fifty patients with drug susceptible typhoid fever were also analysed for comparison. Nineteen of the MDR S. typhi isolates had resistance to ampicillin, chloramphenicol and trimethoprim-sulphamethoxazole (TMP-SMX) while the remainder had resistance to ampicillin and TMP-SMX. The predominant presenting symptoms were fever and diarrhoea. Eleven patients with MDR typhoid fever were treated with oral ciprofloxacin and nine with intravenous ceftriaxone. The patients with MDR typhoid fever had a longer duration of fever defervescence (8 +/- 5 days) compared to those with drug-susceptible typhoid fever (5.7 +/- 4.16 days) (p < 0.01). Eighteen patients were cured and one patient defaulted treatment. Two patients relapsed within two months of treatment. The study showed that 17.4% of patients with typhoid fever had imported MDR S. typhi after recent travel to the Indian subcontinent where MDR typhoid fever is prevalent.

Adult↗
PubMed1994

Acquired immunodeficiency syndrome and Cryptosporidium infection.

A child suffering from the acquired immunodeficiency syndrome (AIDS) with intestinal cryptosporidiosis is reported. The child presented with profuse diarrhoea up to 15 episodes a day over a period of one week. Management was with intravenous rehydration and oral spiramycin. Diagnosis of intestinal cryptosporidiosis requires examination of multiple stool specimens by several concentration and staining procedures which aid in the visualisation of the oocysts. In the absence of an effective treatment for cryptosporidiosis, the cornerstone of management is mainly supportive therapy.

AIDS-Related Opportunistic Infections↗
PubMed1993

Fatal varicella infections in Singapore.

Varicella (chickenpox) is common in Singapore. The annual incidence of reported cases for the period 1977-1990 ranged from 790 to 18,934, with a mean of 4,747. Mortality from chickenpox is rare. However, failure to recognise the severity and the potential complications of the disease, especially in immunocompetent patients, exists because of the common knowledge that chickenpox is a mild and self-limiting illness. We report six cases of fatal varicella in immunocompetent patients during the period 1988 to 1990.

Adolescent↗
PubMed1993

Trends in human immunodeficiency virus infection: epidemiology in Singapore.

The acquired immunodeficiency syndrome (AIDS), caused by the human immunodeficiency virus (HIV) and recognised a decade ago, has reached pandemic proportions worldwide. By early 1992, the World Health Organisation estimates that at least 10 to 12 million people are infected with HIV globally. The majority of these infections are the result of heterosexual transmission. In South and South-east Asia, the AIDS pandemic is growing rapidly due to intravenous drug use and heterosexual transmission. Since 1985, the major route of HIV transmission in Singapore has been sexual. The transmission pattern, however, has changed from one that was predominantly homosexual or bisexual to one that is increasingly heterosexual from mid-1990. In addition, HIV infections among intravenous drug users, children and organ recipients who received transplantation overseas have also surfaced since 1990. It is estimated that there will be 400 cases of HIV infection in Singapore by the mid-1990s.

Acquired Immunodeficiency Syndrome↗
PubMed1992

A 7-day course of ciprofloxacin for enteric fever.

A prospective, open and non-randomised clinical trial using a 7-day short course of oral ciprofloxacin 500 mg twice daily was conducted on 25 adult patients with bacteraemic enteric fever. Twenty-four patients (96%) were cured and there was one treatment failure. Two patients with typhoid fever relapsed 6 weeks after finishing treatment. Defervescence of fever was rapid (median: 4 days) and the duration of hospitalisation was short (median: 8 days). Both factors resulted in patient satisfaction. A short-course regime of ciprofloxacin for the treatment of enteric fever, is therefore, highly promising.

Administration, Oral↗
PubMed1992

Cytomegalovirus pneumonitis in AIDS--a case report.

Respiratory infections occur commonly in patients with advanced human immunodeficiency virus (HIV) infection. Prompt accurate diagnosis is essential as many of the various available therapies have significant toxicities. We describe a patient previously diagnosed with the acquired immunodeficiency syndrome (AIDS) who was found to have cytomegalovirus (CMV) pneumonitis on bronchoscopy. His pneumonitis responded to treatment with the nucleoside analogue ganciclovir. Our patient is the first documented CMV pneumonitis in the Singapore HIV seropositive population.

AIDS-Related Opportunistic Infections↗
PubMed1992

A case of cavitating pneumonia in AIDS.

Tuberculosis is a common cause of cavitating pneumonia in Singapore. In patients with the human immunodeficiency virus (HIV), cavitary pneumonias mimicking tuberculosis can mislead the clinician, delaying diagnosis, resulting in increased morbidity. We describe a HIV seropositive patient with cavitating pneumonia in whom the diagnosis of Pneumocystis carinii pneumonia (PCP) was ultimately established only on bronchoscopy.

AIDS-Related Opportunistic Infections↗
PubMed1992

Diagnostic value of the Widal test for typhoid fever in Singapore.

A study was conducted to assess the diagnostic value of the Widal test in patients with bacteraemic typhoid fever. The Widal test was carried out on 25 bacteriologically proven cases of typhoid fever and 50 patients with non-typhoid fever. All the patients with non-typhoid fever had an O agglutinin titre of less than 1:40, while 82% had an H agglutinin titre of less than 1:40. In the patients with typhoid fever, 56% had an O agglutinin titre of greater than or equal to 1:40 and 72% had an H agglutinin titre of greater than or equal to 1:40. Typhoid patients with titres greater than or equal to 1:40 for O and H antigens of Salmonella typhi were significantly different (P less than 0.01) from those with non-typhoid fever. The O agglutinin was highly specific (100%) in the diagnosis of the disease. The study shows that a single Widal test is useful in the diagnosis of typhoid fever in Singapore.

Adolescent↗
PubMed1991

Human immunodeficiency virus infection in Singapore--containment strategies.

The worldwide occurrence of the Acquired Immunodeficiency Syndrome (AIDS) since its advent in the United States in 1981 has resulted in a global dilemma on how best to reduce transmission of the Human Immunodeficiency Virus (HIV). In Singapore, a national AIDS programme was established in 1985 to control the spread of the disease in the country. The programme included health care delivery, education of health care workers and the community, surveillance and counselling of individuals with high risk behaviours, as well as protection of the nation's blood supply. This paper examines the global response to the HIV pandemic and containment strategies appropriate to Singapore based on established epidemiological data.

AIDS Serodiagnosis↗
PubMed1991

Schistosomiasis in Singapore--a case report.

Schistosomiasis although endemic in the Far East, has not been reported in Singapore. We describe an 83 year-old lady with Schistosoma japonicum infection presenting with bloody diarrhoea. We discuss its diagnosis and postulate the mode of transmission of this infection in urban Singapore.

Aged↗