Effects of Nonpharmaceutical COVID-19 Interventions on Pediatric Hospitalizations for Other Respiratory Virus Infections, Hong Kong.

To determine the effects of nonpharmaceutical interventions (NPIs) for coronavirus disease on pediatric hospitalizations for infection with respiratory viruses other than severe acute respiratory syndrome coronavirus 2, we analyzed hospital data for 2017-2021. Compared with 2017-2019, age-specific hospitalization rates associated with respiratory viruses greatly decreased in 2020, when NPIs were in place. Also when NPIs were in place, rates of hospitalization decreased among children of all ages for infection with influenza A and B viruses, respiratory syncytial virus, adenovirus, parainfluenza viruses, human metapneumovirus, and rhinovirus/enterovirus. Regression models adjusted for age and seasonality indicated that hospitalization rates for acute febrile illness/respiratory symptoms of any cause were reduced by 76% and by 85%-99% for hospitalization for infection with these viruses. NPIs in Hong Kong were clearly associated with reduced pediatric hospitalizations for respiratory viruses; implementing NPIs and reopening schools were associated with only a small increase in hospitalizations for rhinovirus/enterovirus infections.

Epidemiology of Acute Myocarditis/Pericarditis in Hong Kong Adolescents Following Comirnaty Vaccination.

BACKGROUND: Age-specific incidence of acute myocarditis/pericarditis in adolescents following Comirnaty vaccination in Asia is lacking. This study aimed to study the clinical characteristics and incidence of acute myocarditis/pericarditis among Hong Kong adolescents following Comirnaty vaccination. METHODS: This is a population cohort study in Hong Kong that monitored adverse events following immunization through a pharmacovigilance system for coronavirus disease 2019 (COVID-19) vaccines. All adolescents aged between 12 and 17 years following Comirnaty vaccination were monitored under the COVID-19 vaccine adverse event response and evaluation program. The clinical characteristics and overall incidence of acute myocarditis/pericarditis in adolescents following Comirnaty vaccination were analyzed. RESULTS: Between 14 June 2021 and 4 September 2021, 33 Chinese adolescents who developed acute myocarditis/pericarditis following Comirnaty vaccination were identified. In total, 29 (87.88%) were male and 4 (12.12%) were female, with a median age of 15.25 years. And 27 (81.82%) and 6 (18.18%) cases developed acute myocarditis/pericarditis after receiving the second and first dose, respectively. All cases are mild and required only conservative management. The overall incidence of acute myocarditis/pericarditis was 18.52 (95% confidence interval [CI], 11.67-29.01) per 100 000 persons vaccinated. The incidence after the first and second doses were 3.37 (95% CI, 1.12-9.51) and 21.22 (95% CI, 13.78-32.28 per 100 000 persons vaccinated, respectively. Among male adolescents, the incidence after the first and second doses were 5.57 (95% CI, 2.38-12.53) and 37.32 (95% CI, 26.98-51.25) per 100 000 persons vaccinated. CONCLUSIONS: There is a significant increase in the risk of acute myocarditis/pericarditis following Comirnaty vaccination among Chinese male adolescents, especially after the second dose.

Epidemiology and Trends of Infective Meningitis in Neonates and Infants Less than 3 Months Old in Hong Kong.

OBJECTIVES: Meningitis in neonates and young infants leads to significant morbidity and mortality worldwide. This study aimed to investigate pathogens, antibiotic resistance and secular change of incidence in Hong Kong. METHODS: A retrospective search was performed on meningitis in neonates and infants aged <3 months in three Hong Kong public hospitals from 2004 to 2019. Medical charts were reviewed, with focus on the identification and antibiotic resistance of the pathogens. RESULTS: A total of 200 cases of meningitis were identified (67% were bacterial). Group B Streptococcus (GBS) and Escherichia coli (E. coli) were the commonest bacterial pathogens. The annual rates of early-onset GBS meningitis decreased after the implementation of universal GBS screening and intrapartum antibiotic prophylaxis (IAP) in 2012, while that of late-onset GBS meningitis remained similar. A significant portion of E. coli isolates were resistant to ampicillin and/or gentamicin. CONCLUSION: GBS and E. coli were the most common bacteria for meningitis in this age group. The annual rate of bacterial meningitis in Hong Kong has declined in recent years, which has been attributed to the decline in early-onset GBS meningitis due to universal GBS screening and IAP. Antimicrobial-resistant bacterial strains that cause meningitis require further clinical and public health attention.

Clinical Characteristics and Transmission of COVID-19 in Children and Youths During 3 Waves of Outbreaks in Hong Kong.

Importance: Schools were closed intermittently across Hong Kong to control the COVID-19 outbreak, which led to significant physical and psychosocial problems among children and youths. Objective: To compare the clinical characteristics and sources of infection among children and youths with COVID-19 during the 3 waves of outbreaks in Hong Kong in 2020. Design, Setting, and Participants: This cross-sectional study involved children and youths aged 18 years or younger with COVID-19 in the 3 waves of outbreaks from January 23 through December 2, 2020. Data were analyzed from December 2020 through January 2021. Main Outcomes and Measures: Demographic characteristics, travel and contact histories, lengths of hospital stay, and symptoms were captured through the central electronic database. Individuals who were infected without recent international travel were defined as having domestic infections. Results: Among 397 children and youths confirmed with COVID-19 infections, the mean (SD) age was 9.95 (5.34) years, 220 individuals (55.4%) were male, and 154 individuals (38.8%) were asymptomatic. There were significantly more individuals who were infected without symptoms in the second wave (59 of 118 individuals [50.0%]) and third wave (94 of 265 individuals [35.5%]) than in the first wave (1 of 14 individuals [7.1%]) (P = .001). Significantly fewer individuals who were infected in the second and third waves, compared with the first wave, had fever (first wave: 10 individuals [71.4%]; second wave: 22 individuals [18.5%]; third wave: 98 individuals [37.0%]; P < .001) or cough (first wave: 6 individuals [42.9%]; second wave: 15 individuals [12.7%]; third wave: 52 individuals [19.6%]; P = .02). Among all individuals, 394 individuals (99.2%) had mild illness. One patient developed chilblains (ie, COVID toes), 1 patient developed multisystem inflammatory syndrome in children, and 1 patient developed post-COVID-19 autoimmune hemolytic anemia. In all 3 waves, 204 patients with COVID-19 (51.4%) had domestic infections. Among these individuals, 186 (91.2%) reported having a contact history with another individual with COVID-19, of which most (183 individuals [90.0%]) were family members. In the third wave, 18 individuals with domestic infections had unknown contact histories. Three schoolmates were confirmed with COVID-19 on the same day and were reported to be close contacts. Conclusions and Relevance: This cross-sectional study found that nearly all children and youths with COVID-19 in Hong Kong had mild illness. These findings suggest that household transmission was the main source of infection for children and youths with domestic infections and that the risk of being infected at school was small.

Prevalence and risk factors for hypertension in Hong Kong Chinese adolescents: waist circumference predicts hypertension, exercise decreases risk.

PURPOSE: To determine the prevalence, risk factors for and patterns of hypertension in Chinese adolescents based on a territory-wide school based screening programme in Hong Kong. METHODS: Cross-sectional anthropometric and oscillometric blood pressure (BP) measurements and lifestyle information were obtained as part of a growth survey of students from randomly selected secondary schools in Hong Kong. Those with blood pressure ≥ 95th centile were screened a second or third time. Hypertension is defined as elevated blood pressure on three separate occasions. The independent effects of age, sex, body mass index, high waist circumference (≥ 85th centile), sleep duration, family history of hypertension and frequency of exercise on hypertension were explored by multivariate analysis. RESULTS: Among the 6193 students screened, the prevalence of elevated blood pressure on the first, second and third screens was 9.54%, 2.77% and 1.44% respectively. Hypertension was more likely to be systolic. High waist circumference (≥ 85th centile) was independently associated with a higher risk of hypertension (adjusted OR 2.4), while exercising twice or more per week was protective (adjusted OR 0.28). CONCLUSIONS: The prevalence of hypertension in Hong Kong Chinese adolescents is 1.44%. The current study shows high waist circumference is a predictor of hypertension in adolescents, while increased physical activity is a protective factor. Incorporating waist circumference into screening protocols may increase the sensitivity of cardiovascular risk stratification. Healthcare providers should be strong advocates helping to prevent obesity and promote physical activity in adolescents and children.

Evaluating different imaging strategies in children after first febrile urinary tract infection.

We conducted a retrospective multicenter review to estimate the prevalence of urological abnormalities in Chinese children with first febrile urinary tract infection (UTI) and to evaluate the selective imaging strategy recommended by the NICE guideline for detecting underlying abnormalities. Atypical UTI was defined as in the NICE UTI guideline. Overall, 576 boys and 244 girls aged below 24 months were reviewed. All underwent ultrasound (US) and micturating cystourethrogram (MCUG) and 612 underwent DMSA scans. US was abnormal in 73 (8.9%) and vesicoureteral reflux was shown in 195 patients (23.8%). A total of 126 patients were considered to have remediable urological abnormalities requiring additional surgical or medical interventions. The NICE guideline yielded excellent negative predictive values (NPV) of 100-94.4% in girls but 91% in boys. If all boys underwent US and DMSA and only those with atypical UTI or abnormal US or DMSA proceeded to MCUG, then the NPV increased to 95.2% and 97.4% for boys aged below and above 6 months, respectively. These revised strategies would substantially save invasive studies-DMSA and MCUG in 27 and 74% of girls aged below and above 6 months, respectively, or MCUG in 23 and 59% of boys aged below and above 6 months, respectively.

Membranous lupus nephritis in Chinese children--a case series and review of the literature.

We retrospectively reviewed the cases of 13 lupus nephritis children with pure membranous glomerulonephritis (MGN; Group A) and ten children with mixed proliferative and membranous nephritis (Group B). The children were identified through a territory-wide survey of patients between 1990 and 2003. All were ethnic Chinese. Age at diagnosis ranged from 3.7 to 18.6 years (Group A) and from 9.6 to 22.1 years (Group B). Female-to-male ratios were 12:1 (Group A) and 9:1 (Group B). Group A patients were more often nephrotic than Group B patients (11/13 vs. 5/10, p = 0.17). The glomerular filtration rate (GFR) at presentation was normal in all but two patients (one from each group). For induction, Group B patients consistently received prednisolone and cyclophosphamide; in contrast, the cytotoxic regimens in Group A patients varied from cyclophosphamide (five patients), mycophenolate mofetil (two patients), azathiorpine plus cyclosporine (one patient), and azathioprine alone (one patient). After a median follow-up of 7.6-7.8 years, one Group A patient had died of fulminant lupus. One survivor in Group B had a GFR < 90 ml/min per 1.73 m(2). Proteinuria persisted in five Group A patients and two Group B patients. In conclusion, Group B patients had good prognosis in terms of survival and proteinuria control. The only death occurred in Group A, and five of the 12 survivors in this group had persistent proteinuria. Further studies are needed to define the best treatment for pure lupus MGN.

Lupus nephritis in Chinese children--a territory-wide cohort study in Hong Kong.

We report a multicenter study of Chinese children in Hong Kong with systemic lupus erythematosus (SLE) nephritis. Children were included if: they fulfilled the ACR criteria, had significant proteinuria or casturia, were Chinese and younger than 19 years and had been diagnosed with SLE between January 1990 and December 2003. Investigators in each center retrieved data on clinical features, biopsy reports, treatment and outcome of these patients. There were 128 patients (eight boys, 120 girls; mean age: 11.9+/-2.8 years). About 50% presented with multisystem illness and 40% with nephritic/nephrotic symptoms. Negative anti-dsDNA antibodies were found in 6% of the patients. Renal biopsy revealed WHO Class II, III, IV and V nephritis in 13 (10%), 22 (17%), 69 (54%) and 13 (10%) patients, respectively. The clinical severity of the nephritis did not accurately predict renal biopsy findings. The follow-up period ranged from 1 to 16.5 years (mean+/-SD: 5.76+/-3.61 years). During the study five patients died (two from lupus flare, one from cardiomyopathy, two from infections). Four patients had endstage renal failure (ESRF) (one died during a lupus flare). All deaths and end-stage renal failure occurred in the Class IV nephritis group. Chronic organ damage was infrequent in the survivors. The actuarial patient survival rates at 5, 10 and 15 years of age were 95.3, 91.8, and 91.8%, respectively. For Class IV nephritis patients, the survival rates without ESRF at 5, 10, and 15 years were 91.5, 82.3 and 76%, respectively. The survival and chronic morbidity rates of the Chinese SLE children in the present study are comparable to those of other published studies.