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.

Childhood bronchiolitis obliterans in Hong Kong-case series over a 20-year period.

BACKGROUND AND OBJECTIVE: Bronchiolitis obliterans (BO) is a rare but serious condition. The natural history and outcomes remain poorly understood. In this clinical review, we aimed to describe the clinical characteristics and outcomes of children diagnosed with BO in Hong Kong (HK). METHODS: This was a retrospective study of pediatric patients with BO under the care of six respiratory units in HK from January 1996 to December 2015. Information was retrieved from medical records. RESULTS: Fifty-six patients were included with a male predominance (67.9%). The median age at diagnosis was 1.98 years (interquartile range [IQR]: 0.84-4.99 years). Postinfectious BO (PIBO) was the commonest cause (64.3%) followed by posthematopoietic stem-cell transplant (21.4%). Adenovirus (63.2%) was the commonest causative pathogen among PIBO. The median follow-up duration was 9.7 years (IQR: 2.9-14.3 years). Twenty-five patients (44.6%) could achieve symptom-free recovery at the time of follow-up. Five (8.9%) and three (5.4%) were oxygen or ventilator dependent, respectively. There were two deaths, both had posttransplant BO. Patients who developed BO after transplant had significantly worse lung function than those with PIBO. There were no risk factors significantly associated with worse clinical outcomes (oxygen/ventilator dependence or death) by logistic regression. Among patients with PIBO, coinfection at presentation was significantly associated with persistent symptoms at follow-up (p = .028). CONCLUSIONS: The most common cause of childhood BO in HK is postinfectious and coinfection at presentation was associated with persistent symptoms at follow-up. Further studies are needed to better elucidate disease progression, treatment options and long term outcomes.

Chylothorax secondary to catheter related thrombosis successfully treated with heparin.

It has been well recognized that intra-thoracic surgery is a major cause of chylothorax in the newborn period; however, catheter-related thrombosis could also be a cause. We report a preterm baby who presented with right chylothorax secondary to venous thrombosis postinadvertent right internal jugular vein catheterization. The complication resolved with drainage, catheter removal and low molecular weight heparin. The literature on neonatal chylothorax and thrombosis and case reports reporting thrombosis-related chylothorax that have been successfully treated with anticoagulation are reviewed.

Diagnosing acute appendicitis: are we overusing radiologic investigations?

PURPOSE: Acute appendicitis is the most common emergency presenting to pediatric surgeons. With proper history and thorough physical examination, the diagnosis of the condition clinically should approach 90%. With the increasing ease of performing radiologic investigations because of technological advances, more ultrasound and computed tomography (CT) are used to help diagnosing appendicitis. The aim of this study is to review the trend of diagnosing appendicitis in a single center and discuss the implications. METHODS: A retrospective analysis was carried out for all patients who were admitted with acute appendicitis between 1997 and 2007. The methods of diagnosis were divided into 3 groups as follows: clinical, ultrasound, and CT. The demographics and operative findings were noted. Statistical analysis was done using Fisher's Exact test and paired t test when appropriate. A value of P < .05 was considered to be statistically significant. RESULTS: During this period, a total of 254 patients (167 boys and 87 girls) were admitted with appendicitis. The average age at presentation was 12 years, and the mean duration of symptoms before presentation was 2 days. For 11 years, there was an initial rise of the use of ultrasound (10% in 1997 to a peak of 60% in 2005). This percentage decreased with a corresponding rise of the use of CT scan (0% in 1997 to 35% in 2007). There was no correlation found between the use of adjunct investigations and the severity of appendicitis found at operation, suggesting an overreliance of CT. CONCLUSION: It appears that there is an increasing trend in using radiologic investigations for the diagnosis of appendicitis for the past 11 years. With the association of cancer in later life and early radiation exposure well documented, it would be advisable to avoid the use of CT if possible.