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Biomedical subjects

I Snodgrass

Publications and source records attributed to I Snodgrass.

8 recordsLinked to original sources
PubMed1999

Imported malaria in a Singapore hospital: clinical presentation and outcome.

OBJECTIVE: To evaluate the clinical presentation and outcome of imported malaria. METHODS: A retrospective chart review was conducted of patients with imported malaria admitted to the Communicable Disease Centre (CDC), Singapore (a 130-bed tertiary referral center) from January 1992 to December 1993. An imported case was defined as a smear-positive infection that was acquired in another country. RESULTS: Among 200 malaria patients hospitalized at CDC, 168 imported cases (137 males and 31 females, 131 nonresidents and 37 residents) were studied. The mean age was 31.6 6 10.5 years. The countries visited were India (49.4%), Indonesia (16.7%), and Bangladesh (13%). Five patients had chemoprophylaxis and 36 patients had experienced previous malaria infection. The predominant symptoms were fever (97.6%), chills (79.2%), and rigors (67.9%). Hepatomegaly was detected in 56 (33.3%) and splenomegaly in 49 patients (29.2%). Plasmodium vivax was present in 132 patients, Plasmodium falciparum in 29, and mixed P. vivax and P. falciparum in 7 patients. Parasitemia ranged from 0.1% to 8.0%. Of the vivax cases, 130 were treated with chloroquine, followed by primaquine in 123 patients. Quinine was given to 36 patients (29 falciparum malaria and 7 mixed infections). Median time to fever defervescence was 2 days. Complications occurred in three patients (2 with shock and 1 with pulmonary edema). According to World Health Organization gravity criteria, body temperature over 40 degrees C was detected in six patients, bilirubinemia higher than 50 mmol/L in nine, parasitemia over 5% in five, glycemia less than 2.2 mmol/L in two patients. There were five relapses. No death was recorded. CONCLUSION: Plasmodium vivax is the most common cause of imported malaria, with the majority acquired from the Indian subcontinent. Only a few patients presented with severe malaria.

Adolescent↗
PubMed1997

Drug-resistant tuberculosis in Singapore, 1995 to 1996.

Singapore's tuberculosis incidence of 49 to 57 per 100,000 population for 1987 to 1996 presents a picture that is intermediate between developed and developing countries. The proportion of drug-resistant isolates has remained stable at 4.3% to 5.5% from 1992 to 1996 despite rising HIV rates. From 1995 to 1996, of the 199 consecutive drug-resistant isolates at the Central Tuberculosis Laboratory, 66% were mono-resistant, 22% dual-resistant and 12% resistant to more than two drugs. Isoniazid resistance was most prevalent, being found in 72% of isolates, followed by streptomycin resistance in 45%. Resistance to isoniazid and streptomycin (21%) was more common than to isoniazid and rifampicin, i.e. multidrug resistance (MDR) (14%). The small numbers indicated by the low overall prevalence of resistance and the predominance of single-drug resistance support the current initial choice of the standard short course with its three-drug initial phase. Of the 170 cases with matching National Tuberculosis Registry data, 72% of drug-resistant cases represented initial and 28% acquired resistance; testifying to the effectiveness of present day treatment regimens in suppressing resistance when compliance is assured. Case-control analysis using 244 drug-sensitive controls randomly selected from notifications in 1995 to 1996 showed an odds ratio for drug-resistance between subjects with a previous history and no previous history of tuberculosis of 2.47 (95% CI 1.40 to 4.37; P = 0.0007). With each increment in the number of episodes of tuberculosis experienced, there was a trend of resistance to progressively more drugs (P = 0.000004). This association remained even when a logistic regression model including all predictor variables was fitted. No associations were found with age, history of contact with tuberculosis, cavitary disease and, most notably, with human immunodeficiency virus infection. This study reaffirms that a history of previous tuberculosis should increase clinicians' index of suspicion for drug resistance, the urgency with which culture and sensitivity results are sought and the vigour with which patients are followed-up and compliance monitored.

AIDS-Related Opportunistic Infections↗
PubMed1997

The demography, clinical manifestations and natural history of human immunodeficiency virus (HIV) infection in an older population in Singapore.

In this retrospective study, we report 43 cases (41 males and 2 females) of human immunodeficiency virus (HIV) infection in the Singapore population aged 50 years and above at first presentation. We found an increasing proportion of these older individuals among our HIV-seropositive patients; from 4.8% in 1991 to 16.7% by mid-1996. The mean age at presentation was 59.2 years (range 50 to 75 years). They were mainly heterosexuals (93%) and the majority (79.1%) were previously or currently married. Thirty-six (83.7%) patients had multiple sexual exposures to commercial sex workers. Nearly all had acquired the infection through the sexual route. The majority (76.7%) were symptomatic at presentation. Common clinical presentations were weight loss (72%), respiratory symptoms (60%) and oral candidiasis (56%). More than half (58.1%) of the patients had acquired immunodeficiency virus (AIDS) at the time of first presentation with a low median CD4 count of 17 cells/mm3. Pneumocystis carinii pneumonia and tuberculosis were the common AIDS-defining diseases. Survival in patients presenting with AIDS (median survival 3 months) is poorer compared to younger HIV-seropositive patients (< 50 years; median survival 1 year). No increase in age-related infection or malignancy was seen. Common causes of death were pneumonia and septicaemia. Physicians should consider HIV infection in older patients particularly when he/she presents with unexplained weight loss, respiratory symptoms and oral candidiasis. A history of high-risk sexual behaviour must be sought in all patients, including the elderly.

AIDS-Related Opportunistic Infections↗
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

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

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↗
PubMed1989

Significance of the tuberculin test in Singapore.

The standard tuberculin test used by all Singapore government hospitals and institutions is the intradermal Mantoux test using 1 TU of PPD RT23 with Tween 80, and read 72 hours later. There is almost 100% BCG coverage in Singapore children for many years, and therefore the tuberculin skin reaction must be interpreted with special consideration. Taking 8 mm and above as positive, six month old infants vaccinated at birth gave a positive rate of 42% and a mean reaction size of 5.89 mm. The reaction appeared to wane rapidly and among 6 year old school children the positive rate dropped to 12% and the mean size to 2.38 mm. By the age of 11 years, the children showed a positive rate of 36% and a mean size of 6.27 mm. A further increase is observed in 15 year old children, the positive rate being 88% and mean size 13.28 mm. Among tuberculosis contacts, the positive rate and mean size of the tuberculin reaction are generally higher, especially in the younger age groups. Tuberculosis patients above 15 years old were observed to be practically all positive reactors with a mean size of at least 16 mm.

Adolescent↗