The view of Hong Kong parents on secondary use of dried blood spots in newborn screening program.

BACKGROUND: Residual dried blood spots (rDBS) from newborn screening programmes represent a valuable resource for medical research, from basic sciences, through clinical to public health. In Hong Kong, there is no legislation for biobanking. Parents' view on the retention and use of residual newborn blood samples could be cultural-specific and is important to consider for biobanking of rDBS. OBJECTIVE: To study the views and concerns on long-term storage and secondary use of rDBS from newborn screening programmes among Hong Kong Chinese parents. METHODS: A mixed-method approach was used to study the views and concerns on long-term storage and secondary use of rDBS from newborn screening programmes among Hong Kong Chinese parents of children 0-3 years or expecting parents through focus groups (8 groups; 33 participants) and a survey (n = 1012, 85% mothers) designed with insights obtained from the focus groups. We used framework analysis to summarise the themes as supportive factors, concerns and critical arguments for retention and secondary use of rDBS from focus group discussion. We used multiple logistic regression to assess factors associated with support for retention and secondary use of rDBS in the survey. RESULTS: Both in focus groups and survey, majority of parents were not aware of the potential secondary use of rDBS. Overall secondary use of rDBS in medical research was well accepted by a large proportion of Hong Kong parents, even if all potential future research could not be specified in a broad consent. However parents were concerned about potential risks of biobanking rDBS including leaking of data and mis-use of genetic information. Parents wanted to be asked for permission before rDBS are stored and mainly did not accept an "opt-out" approach. The survey showed that parents born in mainland China, compared to Hong Kong born parents, had lower awareness of newborn screening but higher support in biobanking rDBS. Higher education was associated with support in rDBS biobanking only among fathers. CONCLUSION: Long-term storage and secondary use of rDBS from newborn screening for biomedical research and a broad consent for biobanking of rDBS are generally acceptable to Hong Kong parents given their autonomy is respected and their privacy is protected, highlighting the importance of an accountable governance and a transparent access policy for rDBS biobanks.

Correction to: In utero exposure to gestational diabetes and adiposity: does breastfeeding make a difference?

In the original version of this article, the Publisher incorrectly listed the affiliation of the author, G.M. Leung. The correct affiliation for this author should be: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.

In utero exposure to gestational diabetes and adiposity: does breastfeeding make a difference?

BACKGROUND/OBJECTIVES: Short-term breastfeeding from mothers with gestational diabetes (GDM) may programme metabolism and increase offspring diabetes risk. We examined the association of in utero GDM exposure with adiposity from infancy to adolescence, and whether any association was modified by breastfeeding during early infancy. METHODS: In the prospective Chinese birth cohort "Children of 1997" (n = 7342, 88% follow-up rate), generalised estimate equations with multiple imputation were used to assess associations of in utero GDM exposure with age- and sex-specific body mass index (BMI) z-score during infancy (3 and 9 months), childhood (2- < 8 years) and adolescence (8-16 years), adjusted for sex, parity, maternal age, birth place, preeclampisa, smoking, and family socio-economic position. We also tested whether the associations differed by mode of infant feeding (always formula-fed, mixed, always breastfed) during the first three months of life. RESULTS: In utero GDM exposure (7.5%) was associated with a lower BMI z-score during infancy (-0.13, 95% confidence interval (CI) -0.22, -0.05) but higher BMI z-scores during childhood (0.14, 95% CI 0.03, 0.25) and adolescence (0.25 95% CI 0.11, 0.38). Breastfeeding for the first three months did not modify the association of in utero GDM status with subsequent BMI (all p values for interaction >0.4). CONCLUSIONS: In utero GDM exposure was associated with greater adiposity during childhood and adolescence. Breastfeeding in early infancy from mothers with GDM was not associated with greater adiposity in children and thus should still be encouraged.

Dietitian-led lifestyle modification programme for obese Chinese adolescents with non-alcoholic fatty liver disease: a randomized controlled study.

BACKGROUND: The prevalence of non-alcoholic fatty liver disease (NAFLD) in children is increasing. This study evaluated the efficacy of a dietitian-led lifestyle modification programme (D-LMP) to reduce NAFLD in obese adolescents. METHODS: Subjects with intra-hepatic triglyceride content (IHTC) equal to or greater than 5% diagnosed by proton-magnetic resonance spectroscopy (1H-MRS) were enroled and randomly assigned to either the D-LMP intervention or conventional paediatrician-led consultation (P-CON) group. Subjects in the P-CON group received usual care consisting of a consultation by a paediatrician with the child and parents every 16 weeks. Intention-to-treat analysis was used for data analysis. RESULTS: Fifty-two subjects were recruited, with 26 in each group. After the initiation phase (at week-16), there was a greater difference in the change in the IHTC and BMI z-score in the D-LMP group (P = 0.029 and <0.001, respectively) and there was a decrease in dietary intake of fat content (P = 0.019). After 52 weeks of the maintenance phase, both groups had reductions of IHTC to 2-3% and there was no intergroup difference in the rate of reduction. During the maintenance phase, parents' involvement was minimal in the D-LMP group, with only three parents accompanying their children to attend the dietitian sessions. In contrast, over 90% of the parents in the P-CON group regularly accompanied their children to attend the consultations suggesting the possibility that regular parental and paediatrician involvement may contribute to increasing awareness on fatty liver complications. Multivariate analysis showed that only reduction in body fat remained as an independent factor associated with remission of NAFLD at the end of both study phases. CONCLUSIONS: A dietitian-led lifestyle modification intervention reduced IHTC, BMI z-score and body fat in obese Chinese adolescents with NAFLD. To sustain the effect of this intervention, regular parental and paediatrician involvement may be important.

Waist-to-height ratio as a measure of abdominal obesity in southern Chinese and European children and adolescents.

BACKGROUND: Waist-to-height ratio (WHtR), with a 0.5 threshold (WHtR0.5), is regarded as a simple age- and gender-independent criterion of abdominal obesity (AO) and a better predictor than the 90th percentile of waist circumference (WCP90). OBJECTIVE: An analysis of gender and ethnic differences of WHtR and other AO indices between children and adolescents from southern China (HK: Hong-Kong, China) and Europe (LD: Lódz, Poland). SUBJECTS: Two large cross-sectional surveys of children and adolescents aged 7-19 years, one from LD (13 172) and one from HK (14 566). METHODS: The percentile and standardized values of WHtR and other parameters (WC, body mass index (BMI)) were assessed using the LMS method. The WHtR values corresponding to WCP90 and to the BMI definition of global obesity (BMIP95) were evaluated with the polynomial regression model. The compliance of the AO prevalence data, obtained with two criteria (WCP90 vs WHtR0.5) was analyzed using Cohen's kappa index (κC). RESULTS: The WHtR data of Polish subjects were generally higher than those of their HK peers, and the ethic differences increased with age. The WHtR values of HK boys showed a stronger relationship with BMI z-score. WHtR corresponding to WCP90 assumed values <0.5. An application of Cohen's kappa coefficient (κC) to Polish subjects showed either 'substantial' (κC>0.6) or 'almost perfect' (κC>0.8) agreement in the AO prevalence for both criteria (WCP90 and WHtR0.5). For these criteria, either 'fair' (κC <0.4) or 'moderate' (κC<0.6) AO consistency ratings were observed among HK girls. In HK boys, a significant difference in the prevalence of AO was observed, independent of the criterion used. CONCLUSIONS: Our results provide further evidence of the need for developing ethnic-specific WC charts and for recommending that a WHtR cutoff of 0.5 may not be appropriate to predict cardiometabolic risk in children of different ethnic groups.

Normative values of motor performance and their relationship with BMI status in Hong Kong preschoolers.

This study aimed to establish sex- and age-specific reference values for motor performance (MP) in Hong Kong preschoolers aged 3-5 years old and examine the relationship between MP and BMI status. A cross-sectional study was conducted among 5579 preschoolers in Hong Kong. Three MP tests were administered, and height and weight information were collected. GAMLSS was used to compute the normative values of the motor tests. Boys outperformed girls in activities requiring muscle strength and power, while girls outperformed boys in activities requiring balance and coordination. The MP scores increased with age for both overarm beanbag throw and standing long jump for both sexes, while the one-leg balance scores showed larger differences between P50 and P95 in older preschoolers. Children with excessive weight performed worse in standing long jump and one-leg balance compared to their healthy weight peers. This study provides valuable information on the MP of preschoolers in Hong Kong, including sex- and age-specific reference values and the association between BMI status and MP scores. These findings can serve as a reference for future studies and clinical practice and highlight the importance of promoting motor skill development in preschoolers, particularly those who are overweight or obese.

The role of vitamin C in pneumonia and COVID-19 infection in adults with European ancestry: a Mendelian randomisation study.

BACKGROUND: High dose vitamin C infusion has been proposed to treat critically ill patients, including patients with pneumonia and severe COVID-19. However, trials have shown mixed findings. Here we assessed the unconfounded associations of vitamin C with COVID-19 and pneumonia using the Mendelian randomisation approach. METHODS: This is a separate-sample Mendelian randomisation study using publicly available data. We applied single nucleotide polymorphisms (SNPs) that were associated with plasma vitamin C, in a recent genome-wide association study (GWAS) as genetic instruments to the GWAS of severe COVID-19, COVID-19 hospitalisation and any infection in the COVID-19 host genetics initiative and the GWAS of pneumonia in the UK Biobank, to assess whether people with genetically predicted higher levels of plasma vitamin C had lower risk of severe COVID-19 and pneumonia. RESULTS: Genetically predicted circulating levels of vitamin C was not associated with susceptibility to severe COVID-19, COVID-19 hospitalisation, any COVID-19 infection nor pneumonia. Similar results were obtained when a weighted median and MR-Egger methods were used. CONCLUSIONS: Mendelian randomisation analysis provided little evidence for an association of genetically predicted circulating levels of vitamin C with COVID-19 or pneumonia and thus our findings provided little support to the use of vitamin C in prevention and treatment in these patients, unless high dose vitamin C infusion has therapeutic effects via different biological pathways.

Breakfast frequency inversely associated with BMI and body fatness in Hong Kong Chinese children aged 9-18 years.

The present study assessed the relationship between breakfast frequency and measures of obesity in Hong Kong Chinese children aged 9-18 years. A total of 11,570 children (50 % boys) underwent anthropometric measurements and completed a simple self-administered dietary behaviour questionnaire. Their parents completed a questionnaire providing demographic information. Breakfast frequency was assessed by a single question, 'How many days over the past week did you have breakfast?' Children were categorised into three groups: skippers (ate breakfast 0-2 times/week); semi-skippers (ate breakfast 3-4 times/week); non-skippers (ate breakfast 5-7 times/week), to assess all associated characteristics. Of the 3644 primary and 7926 secondary school students, 8 % (8·7 % of boys and 6·9 % of girls) and 14 % (14 % of boys and 15 % of girls), respectively, were breakfast skippers. The prevalence of obesity among breakfast skippers, semi-skippers and non-skippers was, respectively, 9·8, 10·6 and 3·8 % (P < 0·001) for primary school students and 3·9, 3·1 and 2·4 % (P < 0·001) for secondary school students. The 12 % of Hong Kong children aged 9-18 years who skipped breakfast had higher BMI, BMI z-scores and percentage of body fat (PBF) than their counterparts. The dose effects of breakfast frequency (unstandardised regression coefficient, P < 0·001) on BMI and PBF were, respectively, -0·125 kg/m2 and -0·219 % for boys and -0·165 kg/m2 and -0·353 % for girls, adjusting for physical activity per additional breakfast meal per week. Further study is recommended to elucidate whether regular breakfast consumption may have a role in the prevention of childhood obesity.

Implications of using World Health Organization growth reference (2007) for identifying growth problems in Hong Kong children aged 6 to 18 years.

OBJECTIVE: To evaluate the implications of replacing Hong Kong's 1993 growth references (HK1993) with the World Health Organization's 2007 references (WHO2007) for children aged 6 to 18 years. DESIGN: Cross-sectional study. SETTING: Thirty-six randomly selected primary and secondary schools in Hong Kong. PARTICIPANTS: A total of 14 842 children and adolescents aged 6 to 18 years in Hong Kong during 2005/06. MAIN OUTCOME MEASURES: Creation of age-specific z-scores for height, weight, and body mass index relative to HK1993 and WHO2007 references. RESULTS: Use of WHO2007 instead of HK1993 could classify an additional 1.4% children aged 6 to 10 years and 2.8% children aged 11 to 18 years as having a short stature. Using WHO2007, respective proportions that could be classified as underweight and obese increased by 3.5% and 2.1% among children aged 6 to 10 years, and 5.5% and 1.6% among children aged 11 to 18 years. CONCLUSIONS: Use of WHO2007 could increase clinical workload and patient and parent anxiety by 'over-diagnosing' short stature and underweight. Although WHO2007 may have a role in international comparative research, retention of HK1993 would seem appropriate from a clinical perspective.

Factors associated with length of hospital stay in children with respiratory disease.

OBJECTIVES: To explore factors associated with length of stay, and secondarily to explore the potential of enhanced diagnostics to address respiratory disease burden in children. DESIGN: Prospective study. SETTING: A university teaching hospital in Hong Kong. PATIENTS: Data from 475 children with respiratory tract symptoms or fever admitted to Prince of Wales Hospital, Hong Kong from November 2005 to April 2007. MAIN OUTCOME MEASURES: Aetiological diagnoses based on enhanced diagnostics and their association with clinical information. RESULTS: Data from 469 subjects showed that major presentations were fever (84%), cough (72%), and runny nose (64%). The median length of stay was longest (3 days) for adenovirus, metapneumovirus and mycoplasma infections, while children with negative aetiological results had a median length of stay of 2 days. Fever duration during admission (P<0.001), the highest recorded temperature during admission (P < 0.001), use of antibiotics during admission (P<0.001), ear pain before admission (P = 0.019), and high white cell counts (P = 0.021) were associated with increased length of stay (univariate analysis). Identifying an aetiological agent did not affect length of stay. Comparison of children with a positive immunofluorescence test result (rapidly available) with those in whom the test was negative though a positive multiplex polymerase chain reaction ensued (result not available to clinicians) also showed no association with length of stay. CONCLUSION: Although rapid enhanced diagnostics may not have a major influence on length of stay, these data form an integral part of enhanced sentinel surveillance systems.

Identification of viral and atypical bacterial pathogens in children hospitalized with acute respiratory infections in Hong Kong by multiplex PCR assays.

Acute respiratory tract infection is a leading cause of hospital admission of children. This study used a broad capture, rapid and sensitive method (multiplex PCR assay) to detect 20 different respiratory pathogens including influenza A subtypes H1, H3, and H5; influenza B; parainfluenza types 1, 2, 3, and 4; respiratory syncytial virus (RSV) groups A and B; adenoviruses; human rhinoviruses; enteroviruses; human metapneumoviruses; human coronaviruses OC43, 229E, and SARS-CoV; Chlamydophila pneumoniae; Legionella pneumophila; and Mycoplasma pneumoniae; from respiratory specimens of 475 children hospitalized over a 12-month period for acute respiratory tract infections. The overall positive rate (47%) was about twice higher than previous reports based on conventional methods. Influenza A, parainfluenza and RSV accounted for 51%, and non-cultivable viruses accounted for 30% of positive cases. Influenza A peaked at March and June. Influenza B was detected in January, February, and April. Parainfluenza was prevalent throughout the year except from April to June. Most RSV infections were found between February and September. Adenovirus had multiple peaks, whereas rhinovirus and coronavirus OC43 were detected mainly in winter and early spring. RSV infection was associated with bronchiolitis, and parainfluenza was associated with croup; otherwise the clinical manifestations were largely nonspecific. In general, children infected with influenza A, adenovirus and mixed viruses had higher temperatures. In view of the increasing concern about unexpected outbreaks of severe viral infections, a rapid multiplex PCR assay is a valuable tool to enhance the management of hospitalized patients, and for the surveillance for viral infections circulating in the community.

The effect of diet and strength training on obese children's physical self-concept.

AIM: The aim of this study was to examine the effects of a 6-week diet and exercise program, with emphasis on strength training, on the physical self-concept, body composition, and physical fitness of young overweight and obese children. METHODS: Eighty-two overweight and obese children aged 8-11 years were randomized into a diet-only or a diet-and-strength training group. Self-concept, body composition and physical fitness were measured before and after the 6-week study period using the Physical Self Description Questionnaires (PSDQ), dual-energy X-ray absorptiometry (DXA), and standard fitness tests. Dietary intake was assessed with a food frequency questionnaire. Total daily energy intake was significantly reduced in both groups with a trend of more reduction in the diet-only group. RESULTS: Both groups developed greater confidence in strength. Those in the diet-and-strength training group also improved their endurance self-concept. Body Mass Index (BMI) decreased significantly in both groups. Lean mass increased significantly in both groups but significantly more in the diet-and-strength training group (+0.8 kg vs +0.3 kg, P<0.05). Handgrip, shuttle run, sit-up, and push-up were significantly improved in both groups, to a significantly greater extent in the diet-and-strength training group. CONCLUSION: These findings confirm the 6-week program of either diet-only or diet-and-strength training improved overweight/obese children's self-perception of muscular strength and body composition. With the diet-and-strength training program, self-concept in endurance also improved and the gain in lean body mass was more than double that of the diet only group.

Agreement between breast milk dioxin levels by CALUX bioassay and chemical analysis in a population survey in Hong Kong.

Chemically-activated luciferase gene expression (CALUX) bioassay and gas chromatography/mass spectrometry (GC/MS) are used to determine dioxin levels in food and humans. Valid measures of the agreement between the two methods would improve interpretation of bioassay results. Paired breast milk samples from 250 mothers, as 11 pooled samples, were analysed by GC/MS for total WHO-TEQ (7 polychlorinated dibenzo-para-dioxins, 10 polychlorinated dibenzofurans and 12 dioxin-like polychlorinated biphenyls) and as individual samples by CALUX. Mean difference between total WHO-TEQ (weighted by TEF system derived in 1997) and mean CALUX-TEQ in each pool was 1.6 pg/g fat (95% CI: 0.7, 2.4), indicating a statistically significant overestimation of CALUX-TEQ compared to WHO-TEQ, probably due to the presence of Ah-receptor agonists. CALUX estimated toxicity of 13 pg/g fat was greater than the WHO-TEQ by 0.9, 3.1 and 0.3 pg/g fat for mothers from Hong Kong, mainland China and overseas territories, respectively. When the 2005 TEF system was applied, a reduction of 14-26% in the WHO-TEQ and a larger but less disperse discrepancy between WHO-TEQ and CALUX-TEQ (3.9 pg/g fat, 95% CI: 3.5, 4.4) were observed. Our study suggested that the mothers' place of residence explained the discrepancy between CALUX-TEQ and WHO-TEQ and should be considered in inter-country comparisons for CALUX-TEQ. For regulatory purposes bioassays for detecting quantitative dioxin contents in any setting must be combined with adequate extraction, clean-up and validation with WHO-TEQs. The larger difference between the two measurements after using the new TEF system warrants further investigation.

Meal glycaemic load of normal-weight and overweight Hong Kong children.

OBJECTIVE: To describe the pattern of meal glycaemic load of children in Hong Kong and to determine whether the meal glycaemic load is associated with childhood overweight. METHOD: Dietary records (3-day) of 316 Hong Kong children aged 6-7 years were collected. Glycaemic load was calculated from the estimated weight (WT), carbohydrate content (%CHO) and glycaemic index (GI) of each food taken using the equation: (% CHO x GI x WT/100). The meal glycaemic load was then the sum of the glycaemic loads of all food taken in each meal. Logistic regression analyses were used to compare the average meal glycaemic load (of breakfast, lunch and dinner) and other dietary parameters between overweight children and normal-weight children. RESULTS: Breakfast, lunch, dinner and snacks provided, respectively, 17, 29, 29 and 25% of the total glycaemic load in a day. White rice (excluding congee (rice porridge) and glutinous rice) contributed almost half of the total glycaemic load. Adjusted logistic regression showed that the meal glycaemic load was not significantly associated with childhood overweight after adjusting for parental obesity, birth weight, sleeping duration, mean energy intake and paternal smoking. CONCLUSION: Meal glycaemic load calculated from current diet was not an independent factor associated with childhood overweight in children aged 6-7 years. Our data suggested that modifying the type of rice/staple consumed and choosing low-GI snacks could have a major influence on the total meal glycaemic load of young Hong Kong children.

Bone mineral density and calcium metabolism of Hong Kong Chinese postpartum women--a 1-y longitudinal study.

OBJECTIVE: This paper reports longitudinal changes in bone mineral density (BMD), calcium homeostasis and dietary calcium intake in a group of Hong Kong breastfeeding women during the first year postpartum. DESIGN AND SUBJECTS: Nine mothers who breastfed exclusively or almost exclusively for at least 3 months and 14 formula feeding mothers aged 20-40 y were interviewed after delivery, 2 and 6 weeks, 3, 6 and 12 months postpartum. BMD at L2-L4 lumbar spine (LS), trochanter (Tro) and femoral neck (FN), serum intact parathyroid hormone (iPTH), serum bone-specific alkaline phosphatase (b-ALP), urinary deoxypyridinoline (Dpd), serum and urinary calcium (Ca) and phosphorus (P) and dietary intake of macronutrients were assessed. RESULTS: Compared to the formula feeding group, BMD assessed at LS, Tro and FN decreased significantly in the breastfeeding group over the first 6 months, with rebound to approximate baseline values at 12 months for the latter two sites. Serum iPTH increased in both groups, whereas serum b-ALP was consistently higher in the breastfeeders. Urinary Ca and P excretion decreased early postpartum in both groups, but the breastfeeders had higher excretion at 3 and 6 months. Breastfeeding mothers consumed significantly more Ca than the formula feeding mothers in the early postpartum. CONCLUSIONS: Increased calcium requirement during early lactation is affected through mobilisation of bone and renal calcium conservation. Bone mineral loss during lactation is temporary. Further studies are warranted to investigate the effects of diet and other hormonal factors on the calcium homeostasis during lactation.

International Child Care Practices study: breastfeeding and pacifier use.

Although the Baby-Friendly Hospital Initiative advises that no pacifiers be given to breastfeeding infants, both breastfeeding and pacifier use may protect against sudden infant death syndrome. The International Child Care Practice Study data set on child care practices associated with sudden infant death syndrome risk from 21 centers in 17 countries was used to describe infant-feeding practices and pacifier use and assess factors associated with breastfeeding. At approximately 3 months of age, rates of breastfeeding only (4%-80%) and pacifier use(12.5%-71%) varied between centers. Pacifier use was negatively associated with breastfeeding, and a dose-response effect was noted. Other negative (multiple birth, smoking by mother) and positive (intention to breastfeed, bed sharing, mothers' education) associations with breastfeeding only were identified. Although causality should not be inferred, these associations are consistent with previous studies. Advice on pacifiers should include potential benefits as well as risks.

Review of children hospitalised for ingestion and poisoning at a tertiary centre.

INTRODUCTION: The main aim of this study is to determine the pattern of referrals of poisoning to a tertiary university hospital. The information will be used for poison prevention programme planning, and for educating and awareness promoting to the public. MATERIALS AND METHODS: All patients (under 21 years of age) admitted to the paediatric wards between January 1997 and December 2002 with a discharge diagnosis indicating unintentional (UP) or intentional poisoning (IP) were identified through the computerised discharge information. RESULTS: Sixty males and 98 females accounted for 161 admissions over the 6-year period. Their mean (standard deviation, SD) age was 8.2 (6.2) years. Sixty per cent of admissions involved UP. Females accounted for 47% of the UP but 86% of the IP [odds ratio of females for IP, 7.05; 95% confidence interval (CI) 2.95 to 17.28]. When compared with UP, IP patients were significantly older [mean (SD): 14.9 (1.7) versus 3.6 (3.3) years]. In 70% of the admissions, the patients ingested a single substance. Tablets and pills, especially in the IP adolescents, were more commonly ingested than syrups. The spectrum of substances ingested was vast but paracetamol, cough or cold medicines, and common adult household medications and agents accounted for the majority of medications ingested. The substances ingested were obtained at home in 81 cases (50%) and as over-the-counter medication in 33 (20%). The majority (92%) of patients presented within 24 hours of ingestion. On admission, 63% of UP and 45% of the IP were asymptomatic. No active treatment was required in 65% of patients. In IP, nearly 30% of IP who ingested paracetamol had toxic levels and received N-acteyl cysteine. A history of previous poisoning was more common and subsequent follow-up was offered to 74%. CONCLUSION: Young boys were more at risk of unintentional ingestion whereas adolescent girls were more likely to ingest medications as a gesture of suicide. Paracetamol is a frequently ingested medicinal for which an antidote is available.

Incidence of rotavirus diarrhea and intussusception in Hong Kong using standardized hospital discharge data.

Incidence for rotavirus and intussusception was estimated from standardized discharge data for all Hong Kong government hospitals (1997 to 1999). Intussusception incidence in infants (78 to 100 of 100,000) was relatively high. The distinct winter seasonality of rotavirus was not evident for intussusception. During the first 5 years of life an estimated 1 child of 28 is admitted with rotavirus infection (4% of all medical admissions).