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Biomedical subjects

K T Goh

Publications and source records attributed to K T Goh.

At least 91 records · Page 5Linked to original sources
PubMed1986

Isolation of Legionella pneumophila from hospital cooling towers.

Water from twenty cooling towers from three major hospitals (A, B, C) were screened for the presence of Legionella pneumophila. Three of the water specimens were found to be positive for the organism. Serogroup 1 was isolated from the two cooling towers in Hospital A, while serogroup 4 was isolated from one of the cooling towers in Hospital B, this being the first time L. pneumophila has been isolated in Singapore.

Cross Infection↗
PubMed1986

Prevalence of respiratory illnesses of school children in the industrial, urban and rural areas of Singapore.

An epidemiological survey of 3216 primary school children living in the industrial, urban and rural areas of Singapore revealed a high prevalence of various respiratory symptoms and illnesses, with 13.1% cough, 8.2% wheezy chest, 25.9% blocked/running nose, 4.3% sinusitis, 7.8% asthmatic attacks and 4.1% bronchitis/pneumonia. Differences in the prevalence of respiratory illnesses and lung function tests were observed among children in the three areas, but this could not be accounted for by the varying air pollution levels which have been maintained below the long-term standards set up by WHO. It was probably responsible for the differences noted.

Adolescent↗
PubMed1985

Maternal-child hepatitis B virus transmission in Singapore.

A study of maternal-infant transmission of hepatitis B virus (HBV) was conducted in Singapore between June 1980 and June 1982. HBsAg carrier rate was highest among Chinese (6.2%) followed by Malay (2.3%) and Indian (0.6%) mothers. The presence of HBeAg in maternal sera correlated well with high titre HBsAg (p = 7.34 X 10(-5)). Overall HBV transmission occurred in 27/56 (48.2%) infants from carrier mothers. The majority of the transmission was perinatal. There was a very strong correlation between transmission and HBeAg status of the mother (p = 1.85 X 10(-9); odds ratio = 68.44) and to a lesser extent with high titre HBsAg (p = 0.002; odds ratio = 6.38). A strong negative correlation was seen between transmission and anti-HBeAg (p = 8.19 X 10(-7); odds ratio = 0.04). At one year 19 (70.4%) infants were still HBsAg positive while seven (25.9%) lost the antigenemia and acquired anti-HBsAg and one developed HBsAg after one year. It could be calculated that perinatal HBV transmission contributed about 18% to the total pool of HBsAg positive infants of one year of age.

Carrier State↗
PubMed1985

Hepatitis B infection in households of acute cases.

Seroepidemiological studies conducted in 369 household contacts of 80 acute cases of hepatitis B in Singapore showed that asymptomatic chronic carriers of hepatitis B surface antigen (HBs Ag) are the main source of acute hepatitis B infection. The HBs Ag prevalence rate in asymptomatic household members was 20% compared with a 6% prevalence for the general population. The majority of the household carriers (60%) were highly infectious with positive hepatitis e antigen (HBe Ag). The overall prevalence of HBV infection (with at least one HBV marker) of the household contacts was 40.7%. Spouses and parents of acute cases had a significantly higher prevalence of HBV infection than other members of the families. HBV prevalence rate showed no association with the household size. Factors associated with the risk of transmission of HBV infection included sharing of various personal and household articles, such as toothbrush, towel, handkerchief, clothing, razor, comb, bed and bedding. Sleeping in the same bedroom, eating together at meals, and sharing of eating and drinking utensils were not associated with an increased risk of transmission of infection. Follow-up studies six months later showed that 30% of the acute cases became chronic HBs Ag carriers (with 46% HBe Ag positive), thus providing an additional source of infection in the families, while 8% of the susceptible household members acquired asymptomatic HBV infection. Health education on the prevention of HBV transmission in the homes of acute cases should be based on sound epidemiological information. Household contacts of acute cases of hepatitis B should be routinely screened and the susceptible vaccinated against the disease as soon as possible.

Acute Disease↗
PubMed1985

Disease-bearing insects brought in by international aircraft into Singapore.

Fifty-seven (17.3%) of 330 incoming aircraft landing at Changi International Airport were found to harbour mosquitoes and other insects on board. The frequency of insects detected in aircraft from the Southeast Asian countries varied from 7.1% to 32.2%. Live insects were found in 5 (6.1%) of 82 aircraft disinsectized by the "block away" method. The species of mosquitoes brought in were: Culex quinquefasciatus (96), Culex tritaeniorhynchus (1), Aedes albopictus (2) and Aedes aegypti (1). None of the 51 female Culex quinquefasciatus dissected was found to be infected with microfilariae. They key to the prevention of introduction of exotic vectors and transmission of vector- borne diseases is to continue with the existing system of vector surveillance and control at the international airport, rather than routine disinsecting of aircraft landing in Singapore.

Aircraft↗
PubMed1984

A common source foodborne outbreak of cholera in Singapore.

An epidemiological investigation of an outbreak of Vibrio cholerae 01, biotype El Tor, serotype Ogawa, phage type 1, confined to a group of foreign construction workers in Singapore is described. A total of 22 workers were confirmed to have cholera and another 15 had asymptomatic Vibrio cholerae 01 infection between 3 November and 11 November 1982. The source of infection was traced to contaminated seafood prepared at the construction site canteen where two food handlers were found to be infected with V. cholerae 01 (one symptomatic and the other asymptomatic). The incubation period of cholera in this outbreak ranged from 4 to 203 hours with a median of 38 hours. Only two workers had moderate to severe dehydration and required intravenous therapy. Early recognition of the outbreak and prompt implementation of control measures prevented the outbreak from spreading to other parts of Singapore.

Adolescent↗
PubMed1984

Imported communicable diseases in Singapore.

Most communicable diseases in Singapore have been brought under control and some eliminated. In recent years, an increasing proportion of the reported cases turned out to be imported. Between the period 1977 and 1982, 96% of malaria, 44% of paratyphoid, 32% of typhoid, 20% of leprosy, 11% of acute viral hepatitis, 7% of dengue fever/dengue haemorrhagic fever and 7% of cholera were imported. About 10% of the notified tuberculosis cases were non-residents while all the sporadic cases of poliomyelitis (except in 1977) and diphtheria (except in 1982) were contracted outside Singapore. The majority of the infections originated from Southeast Asia and the Indian subcontinent. The main groups of population with imported infections were local residents who travelled to the endemic areas without taking adequate preventive measures, foreign contract workers, and foreign seeking medical treatment in Singapore. Whether or not these imported cases would spread the infection to others in the community and cause epidemics depend on the virulence of the pathogen introduced, the susceptibility of the population and the environmental conditions which favour transmission of infection. Measures taken to reduce the risk of transmission include provision of a high standard of environmental sanitation, epidemiological surveillance to detect and eliminate the focus of infection; maintenance of a high level of herd immunity through immunisation; health education of the medical practitioners and of the public on the need for personal prophylaxis when travelling overseas; and screening of foreign contract workers and returning residents in special situations.

Adolescent↗
PubMed1984

An epidemic of cockles-associated hepatitis A in Singapore.

An epidemic of serologically confirmed hepatitis A occurred between May and September 1983 in Singapore. The vehicle of transmission was traced to raw and partially cooked cockles, Anadara granosa, which had been imported from places with no sanitary control on the production. Strict controls on imported cockles are warranted.

Adolescent↗
PubMed1982

An outbreak of hand, foot, and mouth disease in Singapore.

Epidemiological studies were carried out during an extensive outbreak of hand, foot and mouth disease caused by coxsackievirus A 16 in Singapore in 1981. Most of the cases were concentrated in densely populated public housing estates, and the morbidity rate was highest in children under 5 years of age. The mean secondary attack rate for children under 12 years of age was 76.7% compared with an overall rate of 31.3%. The incubation period ranged from 1 to 7 days. Factors favouring the transmission of infection within a household included sharing of household and personal articles with the index case. The disease was mild and self-limiting.

Adolescent↗
PubMed1981

An epidemic of acute conjunctivitis caused by enterovirus-70 in Singapore in 1980.

The clinical, epidemiological and virological findings of the 1980 epidemic of acute conjunctivitis were described. Enterovirus 70 was isolated from 7 (35%) of 20 eye swabs submitted for virus isolation, and the paired sera of eight patients showed a four-fold or greater rise in neutralising antibody titre to Enterovirus 70. The disease mainly affected children and young adults of all ethnic groups. Most of the cases contracted the infection at home. The mean secondary attack rate was 72.6% and the mean incubation period, four days. The clinical features were similar to the 1970 and 1975 epidemics caused by Coxsackievirus A24. Subconjunctival haemorrhage was observed in 10% of the cases. Most of the cases recovered spontaneously within a week. Transmission of infection within the home was either indirect, probably through fomites contaminated with eye or respiratory discharges of cases, or direct, through intimate person-to-person contact. During outbreaks, health education on simple personal hygiene should be highlighted.

Acute Disease↗
PubMed1981

An outbreak of paratyphoid A in Singapore: clinical and epidemiological studies.

The epidemiological and clinical findings of 61 cases of laboratory-confirmed paratyphoid A reported in an outbreak in 1979 were described. Epidemiological investigations of 42 indigenous cases implicated imported fresh oysters as the vehicles of transmission (p less than 0.01). Although S. paratyphi A could not isolated from the implicated oysters, several observations presented tend to support the association between oyster consumption and illness. The clinical features were similar to typhoid, 82.8% of the organisms were isolated from blood cultures. The relapse rate was 8.6%. There were three stool and one urinary convalescent carriers. Two of the stool carriers were treated with cholecystectomy.

Adolescent↗
PubMed1981

Vibrio infections in Singapore.

Both symptomatic and asymptomatic Vibrio infections, caused by V cholerae, V parahaemolyticus and NAG vibrios, occurred in Singapore. V cholerae are introduced into the country from time to time, but the risk of transmission of infection in the community is negligible in the presence of a high standard of environmental sanitation and a well-established system of epidemiological surveillance. As cholera is probably transmitted through contaminated food, shellfish imported from cholera-endemic countries are regularly monitored for the presence of V cholerae. Vigilance has also been stepped up in the laboratory in view of the possibility of introduction of multiple-antibiotic resistant V cholerae strains into the country. V parahaemolyticus is one of the commonest causes of bacterial food poisoning in Singapore because of the preference of the local population to consume raw or partially cooked seafood. 78% of a variety of imported seafood were found to be contaminated with V parahaemolyticus. Infections caused by NAG vibrios are infrequent, and the mode of transmission has not been established.

Adolescent↗
PubMed1981

Epidemiological studies of Hepatitis A in Singapore.

1,341 cases of Hepatitis A were reported during the 44-month period between January 1977 and August 1980. The morbidity rate per 100,000 population varied from 9.4 in 1977 to 25.2 for the first eight months of 1980. The case fatality rate was 1.0%. Among the three major ethnic groups, Indians had the highest morbidity rate; but during outbreaks, the attack rate was highest among the Chinese. High age-specific morbidity rate was noted in the 15-34 years age group. The male to female ratio was 2.9: 1. 7.4% of the cases contracted the disease overseas while 7.2% gave a contact history with known hepatitis cases. Contact with unrecognised asymptomatic or mild cases in the community could probably be the mode of transmission for a considerable proportion of the reported cases. Ingestion of raw or partially cooked imported bivalve molluscs (cockles and oysters) was associated with an outbreak in September 1978 and the outbreaks in 1980. The possibility of low-level transmission by water should be seriously considered.

Adolescent↗