E. A. S. Nelson

Risk factors for childhood overweight in 6- to 7-y-old Hong Kong children.

OBJECTIVE: To identify risk factors for overweight in Hong Kong children aged 6–7 y.DESIGN: Case–control study.SETTING: Student Health Service Centres, Hong Kong.SUBJECTS: A total of 343 Hong Kong Chinese children aged 6–7 y old categorised into three groups, an overweight group (≥92nd centile for BMI), a normal middle-weight group (45th–55th centile for BMI) and a normal low-weight group (≤8th centile for BMI).MEASUREMENTS: Subjects and their parents/caregivers were interviewed at home. Data on lifestyle habits, dietary habits, family structure and demographic background were collected by questionnaire. A 3-day dietary record was administrated by the parents/caregivers to assess dietary intake of the children.RESULTS: Logistic regression analyses (overweight group compared with middle-weight plus low-weight groups) showed that childhood overweight was significantly associated with parental obesity (BMI ≥25 kg/m2, Asian reference) (paternal: OR=2.66, 95% CI=1.51–4.70; maternal: 5.07, 2.62–9.79) but not parental overweight (BMI=23–25 kg/m2). After adjustment for parental obesity, the odds ratio for childhood overweight was increased by birth weight (<3.0 kg as reference, 3.0–3.5 kg: 2.13, 1.18–3.84; ≥3.5 kg: 4.89, 2.49–9.60) and decreased by sleeping duration (<9 h/day as reference, 9–11 h/day: 0.54, 0.30–0.97; ≥11 h/day: 0.31, 0.11–0.87). Childhood overweight was also significantly associated with higher energy consumption (2.62, 1.20–5.74) and having a father who was a current smoker (2.08, 1.25–3.46).CONCLUSIONS: Although healthy diet and regular exercise will remain the cornerstones of obesity management in children, our data support the view that education about maintaining a healthy weight could be introduced much earlier in those families with high-risk children, as indicated by high parental BMI or high birth weight. The utility and practicality of such an approach should be carefully evaluated before becoming part of any public health policy. Further study of the role of short sleeping duration and parental smoking on childhood obesity development is warranted.

Rotavirus infection in Hong Kong: epidemiology and estimates of disease burden.

Rotavirus gastroenteritis should soon be a vaccine-preventable disease. In a 10-year survey of rotavirus gastroenteritis conducted at the Prince of Wales Hospital (PWH), 2281 cases were detected of which 2213 (97%) occurred in children < 5 years old. A consistent epidemic occurred each winter during the months of December and January. Of all laboratory-confirmed cases, 78% were community-acquired with a mean hospital stay of 4.7 days. The estimated incidence of rotavirus-attributed hospitalization was 2/1000 children < 5 years old. Over the 10 years, rotavirus was responsible for one death, and contributory to three other deaths. On average each year, 195 children < 5 years old were hospitalized for a total of 917 days in PWH, accounting for an estimated expenditure of HK

Invasion and growth of Plasmodium falciparum is inhibited in fractionated thalassaemic erythrocytes

2.8 (approximately US

Surveillance of childhood diarrhoeal disease in Hong Kong, using standardized hospital discharge data

0.4) million on hospitalization costs. The annual financial burden for rotavirus gastroenteritis for the whole of Hong Kong could be in excess of HK

Flow cytometric assessment of oxidant stress in age-fractionated thalassaemic trait erythrocytes and its relationship to in vitro growth of Plasmodium falciparum

9.6 (approximately US

Poverty focused assistance: new category of development aid

1.2) million.

In vitro sensitivity of artemeter in Plasmodium falciparum-infected beta-thalassaemic trait erythrocytes.

Epidemiological and clinical studies have indicated that the thalassaemias may confer protection against malaria. The study reported here investigated this protective effect in vitro, using a new approach which controls for the potential effect of red cell size and age on the virulence of the parasite. A Percoll density gradient method was used to separate alpha- and beta-thalassaemic trait, haemoglobin H and normal red blood cells (RBC) into fractions of different density. Correlations between RBC density, age and size in fractions of all genotypes were established using red cell creatine as an index of cell age. The development of Plasmodium falciparum over 3 erythrocytic cycles (144 h) in whole blood as well as fractionated samples was monitored by slide microscopy and flow cytometry. A significantly reduced rate of parasite invasion and growth was demonstrated in RBC from all thalassaemic genotypes tested. Poor reinvasion rates were noted in the second and third cycles. Increased duration of culture and red cell age also had a greater negative impact on parasite growth in thalassaemic RBC. This poor growth rate was also associated with the arrest of parasite growth at the schizont stage (schizont maturation arrest) and the accumulation of abnormal, trophozoite/schizont stage parasites in the older thalassaemic RBC fractions. These findings suggest a defect in the number and viability of merozoites generated by parasites growing in thalassaemic RBC. Age related factors such as oxidant stress may play a key role in mediating this kind of protective mechanism and deserve further investigation.

Thalassaemia trait, red blood cell age and oxidant stress: effects on Plasmodium falciparum growth and sensitivity to artemisinin

Discharge information for all Hong Kong government hospitals, which is routinely collected through the Clinical Management System (CMS), was used to assess the relative importance of all causes of diarrhoeal illness and to address the issue of under-diagnosis of rotavirus by linking discharge diagnostic codes with actual laboratory results for one hospital. Of all children less than 5 years of age hospitalized in Hong Kong in the 2-year period July 1997 to June 1999, 12,257 (11%) were discharged with a primary diarrhoea diagnosis (74% coded as non-specified, 10.4% as rotavirus, 11% as Salmonella and 5% as other viral or bacterial). Linked laboratory and discharge data for one hospital demonstrated that 15% (n = 1522) of all admissions had a primary diarrhoea diagnosis and that 40% of these had a specimen sent for rotavirus testing, of which 37% were positive. However, 46% (67/145) of children with a diagnosis of rotavirus infection had no virology result, and 69% (172/248) of positive rotavirus results were in children with no diagnosis indicating rotavirus infection. Modification of the CMS to routinely combine existing computerized laboratory data with the CMS discharge diagnoses and to develop mechanisms to enhance reliability of discharge diagnosis coding could produce a powerful resource for disease surveillance, auditing and for monitoring the impact of future vaccination and other prevention programmes.

Acute gastroenteritis in Hong Kong: a population-based telephone survey

The role of oxidant stress in mediating the protection against malaria in thalassaemic red blood cells (RBC) has been hypothesized. In this study we have assessed the relationship between oxidant stress, red cell age and malarial parasite activity in thalassaemic RBC. Using a flow cytometric method to assess lipid peroxidation, we have shown that the age-related increase in sensitivity to oxidative stress previously demonstrated in normal RBC also occurs in thalassaemic RBC. Invasion and growth of Plasmodium falciparum was also shown to deteriorate with increasing RBC age. This effect was more pronounced in thalassaemic RBC with associated schizont maturation arrest and abnormal parasite morphology. In addition, there was a slight but consistent inverse correlation between sensitivity to oxidant stress and parasite activity (R = -0.43; P = 0.03 for normal RBC and R = -0.42; P = 0.01 for thalassaemic RBC). Our findings indicate an association between red cell age, oxidant stress and P. falciparum growth, providing further support for the role of oxidant stress in mediating the protective effect against malaria in thalassaemic RBC.

Evaluation of a peer counselling programme to sustain breastfeeding practice in Hong Kong

ODASS is now at its lowest level in real terms for 25 years. When governments flaunt such commitments it is easy to be pessimistic. Yet the commitments and programme of action of WSSD provide an idealised blueprint from which steps can be taken to advocate for change. Dissemination of information clearly identifying what governments have, and have not, achieved will be a further part of this process. To this end we analysed British ODASS in greater detail. Although British ODASS has been criticised for being inappropriate, it is also thought by some to be one of the more effective and poverty-focused aid programmes. The results outlined below are thus not intended to represent a bestcase or worst-case scenario, but to draw attention to the issues and make constructive recommendations to improve the effectiveness and appropriateness of ODASS. The average annual British ODASS for the 5 years 1989–93 was 0·3% of gross national product (GNP), equivalent to an average of US