Endobronchial mucosal nodules and actinomycosis in a child with activated phosphatidylinositol 3-kinase delta syndrome (APDS).

In this report, we describe a case of a 5-year-old girl with poor growth and unresolving pneumonia. Bronchoscopy showed numerous endobronchial mucosal nodules, consisting of dense lymphoid infiltrates. Bacterial culture of the nodule biopsy suggested endobronchial actinomycosis. Genetic test confirmed the diagnosis of APDS.

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.

Influenza vaccine effectiveness in hospitalised Hong Kong children: Feasibility of estimates from routine surveillance data.

BACKGROUND: Hong Kong has a high burden of influenza hospitalisation. This study estimated influenza vaccine effectiveness in hospitalised Hong Kong children aged 6 months to below 6 years using data potentially obtainable from routine surveillance sources. METHODS: This 'test-negative' case-control study was conducted over two summer and one winter influenza seasons in five public Hong Kong hospitals during 2015 and 2016. Patients admitted for febrile and/or respiratory-associated illnesses who met inclusion criteria were invited to participate. Case-patients were respiratory-associated admissions with nasopharyngeal aspirate or nasopharyngeal swab specimens obtained during the first 48 h of hospitalisation that tested positive for influenza A or B, whereas control-patients were those with specimens that tested negative for both influenza A and B. Reliability of a routinely collected influenza immunisation status form was evaluated. Vaccine effectiveness for administration of full or partial series of influenza vaccination was calculated as 1 minus the odds ratio for influenza vaccination history for case-patients versus control-patients. RESULTS: 2900 eligible subjects had influenza vaccination status available. A simple record form, designed to collect upon admission information on influenza vaccination status, was found to be reliable when compared to confirmed vaccination status from immunisation records and guardians' self-reports. Influenza vaccine effectiveness for preventing influenza A or B hospitalisation in children aged from 6 months to below 6 years during the period June 2015 to November 2016 was 68% (95% confidence interval [CI]: 55%, 77%) from unconditional analyses and 64% (95% CI: 46%, 75%) from conditional analyses. CONCLUSIONS: Seasonal influenza vaccine was effective in preventing hospitalisation from influenza A or B in young Hong Kong children during 2015 and 2016. As influenza vaccination status is not currently routinely recorded, implementation of an influenza immunisation status form in all paediatric wards, and centralising the data in Hong Kong's central computerised database, could provide real-time monitoring of influenza vaccine effectiveness.

Rapid defervescence after doxycycline treatment of macrolide-resistant Mycoplasma pneumoniae-associated community-acquired pneumonia in children.

We did a retrospective review of children with Mycoplasma pneumoniae infection hospitalized from March 2010 to March 2013. Mycoplasma-resistant M. pneumoniae constituted 70% of the total M. pneumoniae-associated community-acquired pneumonia. Doxycycline was significantly more effective than macrolide for treatment of Mycoplasma-resistant M. pneumoniae-associated community-acquired pneumonia in terms of achievement of rapid defervescence within 24 hours.

Hemorrhagic shock and encephalopathy syndrome in a child with pandemic H1N1 2009 influenza virus.

We report a case of hemorrhagic shock and encephalopathy in a child with pandemic 2009 H1N1 influenza infection. The patient succumbed within 3 days of admission.

Fatal viral infection-associated encephalopathy in two Chinese boys: a genetically determined risk factor of thermolabile carnitine palmitoyltransferase II variants.

Influenza-associated encephalopathy (IAE) is a potentially fatal neurological complication of influenza infection usually in the presence of high and persistent fever. Thermolabile carnitine palmitoyltransferase II enzyme (CPT-II) predisposes IAE, so far only described in Japanese. As the genetic origins of Japanese and Chinese are alike, similar genetic risk factors in CPT-II are expected. We report the first two unrelated Chinese patients of thermolabile CPT-II variants that underlain the persistent high fever-triggered viral infection-associated encephalopathy, multi-organ failure and death. Elevated (C16:0+C18:1)/C2 acylcarnitines ratio and the CPT2 susceptibility variant allele [p.Phe352Cys; p.Val368Ile] were detected. The asymptomatic family members of one patient also had abnormal long-chain acylcarnitines. In our experience of biochemical genetics, the elevated (C16:0+C18:1)/C2 acylcarnitines ratio is unusual and specific for thermolabile CPT-II variants. Allele frequency of [p.Phe352Cys; p.Val368Ile] among Hong Kong Chinese was 0.104, similar to Japanese data, and [p.Phe352Cys] has not been reported in Caucasians. This may explain the Asian-specific phenomenon of thermolabile CPT-II-associated IAE. We successfully demonstrated the thermolabile CPT-II variants in patients with viral infection-associated encephalopathy in another Asian population outside Japanese. The condition is likely under-recognized. With our first cases, it is envisaged that more cases will be diagnosed in subsequent years. The exact pathogenic mechanism of how other factors interplay with thermolabile CPT-II variants and high fever leading to IAE, is yet to be elucidated. Fasting and decreased intake during illness may aggravate the disease. Further studies including high risk and neonatal screening are warranted to investigate its expressivity, penetrance and temperature-dependent behaviors in thermolabile CPT-II carriers. This may lead to discovery of the therapeutic golden window by aggressive antipyretics and L-carnitine administration in avoiding the high mortality and morbidity of IAE.