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Biomedical subjects

A E Ling

Publications and source records attributed to A E Ling.

46 records · Page 3Linked to original sources
PubMed1988

Influenza surveillance in Singapore: 1972-86.

Prospective laboratory surveillance of influenza viruses has been carried out since 1973 in Singapore. The results indicate that antigenic shift variants caused epidemics at various times of the year over this period, whereas drift variants were associated with a regular increase in incidence during the second and fourth calendar quarters. Outbreaks due to influenza A virus occurred every year and to influenza B virus at intervals of 16-24 months. Between outbreaks, viruses belonging to either of the two types could be detected during most months, and certain variants appeared several months before the outbreaks they subsequently caused. The factors that contribute to the seasonal pattern are at present unknown.

Adolescent↗
PubMed1987

Epidemiology of viral infections in Singapore.

As Singapore is a densely populated island, and also a major air and sea port, the importation and dissemination of viral infections is facilitated. Respiratory viral infections have the highest prevalence rates, influenza and respiratory syncytial virus (RSV) being the most important ones. Seasonal variation occurs with influenza, RSV and parainfluenza virus type 1 infections. The age distribution and clinical picture associated with infections due to the various respiratory viruses are similar to those reported in other countries. Carrier rates for hepatitis B are high, but differ in the three major ethnic groups, vertical transmission from infected mothers being an important mode of transmission. Outbreaks of hepatitis A have been associated with the consumption of inadequately cooked shellfish. Cytomegalovirus and Epstein-Barr virus infections are acquired early in life and herpes simplex, more slowly. Genital herpes is increasing in incidence. Coxsackievirus A24 and enterovirus 70 have caused major epidemics of acute haemorrhagic conjunctivitis at 5-10 year intervals. Outbreaks of hand, foot and mouth disease due to coxsackievirus A16 have also occurred. With the declining incidence of dengue haemorrhagic fever, the percentage of susceptible individuals in children under 10 years, has increased markedly. Epidemics of rubella which occurred during the past decade, together with immunisation, have increased herd immunity to this virus.

Adolescent↗
PubMed1987

Acute hepatitis A in Singapore: importance of shellfish ingestion in a non-epidemic period.

A case-control study based on 28 serologically confirmed cases of hepatitis A and 42 home contacts with no recent or past evidence of hepatitis A virus (HAV) infection was conducted to determine the importance of shellfish exposure in the transmission of HAV during a non-epidemic period in Singapore. It was found that consumption of partially-cooked cockles (Anadara granosa) was significantly associated with the illness (p less than 0.001). No other types of locally available shellfish including oysters, mussels and clams were incriminated. The public should be constantly reminded to refrain from consuming raw and inadequately cooked bivalve molluscs all the time, and not just during epidemics.

Acute Disease↗
PubMed1987

Genital herpes in Singapore.

As in many parts of the world, the incidence of genital herpes has increased in Singapore, the increase occurring sharply from 1982 onwards, and affecting females to a greater extent than males. Peak incidence in both sexes was found to occur in the 15-34 year age group. Changes in sexual practices, a decreasing prevalence of age-specific antibody to herpes simplex type 1 virus in sexually active adults, and greater interest in the disease following publicity in the media, are factors which have contributed to both a real and an apparent increase in incidence. However, the incidence in Malay males is very low, and neonatal herpes is extremely rare in the local population. Herpes simplex virus type 1 is responsible for about 30% of initial genital infections and an even higher proportion of primary genital herpes infections. Approximately 16% of purulent penile ulcers in Singapore are associated with genital herpes infection.

Adolescent↗
PubMed1986

Purulent penile ulcers of patients in Singapore.

In 80 patients with painful purulent penile ulcers who attended the outpatient service of Middle Road Hospital in Singapore, Haemophilus ducreyi was isolated from 18 (22%), herpes simplex virus type 2 from nine (11%), and Neisseria gonorrhoeae from eight (10%). Primary pathogens were not isolated from 45 (57%) men. Painful purulent penile ulcers were more common in uncircumcised men, and patients had often acquired the disease after sexual intercourse with prostitutes in Singapore.

Adolescent↗
PubMed1986

Foscarnet (phosphonoformate sodium) in the treatment of recurrent male genital herpes.

Foscarnet 0.3% cream was compared with placebo in a randomised double-blind study. The objective was to investigate the therapeutic efficacy and safety in men with recurrent genital herpes simplex virus (HSV) infections. A total of 51 patients were selected, of which 49 (25 treated with foscarnet) were valid for efficacy analysis. Different variables were analysed including the time to healing, alleviation of symptoms, side effects and the results of viral cultures. The median time to healing was 4 days in foscarnet treated patients compared to 5 days in placebo controls. The difference was not statistically significant (p = 0.22). However, foscarnet alleviated the severity of pain and also significantly reduced the median time to abolition pain to 3 days from 6.6 days in placebo treated patients (p = 0.0028). An antiviral effect of foscarnet was evident. The percentage of positive viral cultures found after starting treatment was 15% in the foscarnet-treated group compared to 44% in the placebo-treated group (p = 0.01). Treatment with foscarnet cream was not associated with any significant side effects.

Administration, Topical↗
PubMed1986

Patterns of viral respiratory tract infections in Singapore.

A second retrospective study on viral respiratory tract infections, based on 12 years' laboratory reports for the influenza viruses, and 9 years' reports for the other respiratory viruses was made. Seasonal variation in incidence was found to occur with infections due to the influenza viruses, respiratory syncytial virus, and parainfluenzavirus type 1. Observations made previously on the age distribution of specific respiratory viral infections, and the association of the viruses with various respiratory syndromes were generally confirmed.

Adenovirus Infections, Human↗
PubMed1981

Acute non-bacterial infections of the respiratory tract in Singapore children: an analysis of three years' laboratory findings.

A retrospective study of the laboratory results on respiratory specimens received from children under 12 years of age between January 1977 and December 1979 was carried out. These children were either hospital patients, usually with lower respiratory infections, or outpatients on the Influenza Surveillance Programme. The overall virus isolation rate was 26.8%, and the isolation rate among hospital patients, 38.5%. Epidemics or outbreaks were associated with infections due to the influenza viruses, respiratory syncytial virus (RSV), the parainfluenza viruses and the enteroviruses. RSV, parainfluenza virus types 1 and 3, and the adenoviruses caused infection mainly in young children under 3 years of age, while the influenza viruses and Mycoplasma pneumoniae caused infection more frequently in older, school-aged children. There was a strong clinical association of bronchiolitis with RSV and the rhinoviruses, of laryngitis or laryngotracheobronchitis with parainfluenza virus types 1 and 2, of pneumonia with Mycoplasma pneumoniae, and of upper respiratory infection or "flu" with the influenza viruses. The significance of some of these findings is discussed.

Acute Disease↗