Publications by authors named "Chee F Yung"
Aim: Continuous monitoring of blood culture (BC) systems allows rapid detection of microbial growth. We aimed to determine differences in time to positivity (TTP) in BACTEC BC between organisms and whether a 36-h period was sufficient to detect all relevant pathogenic bacteria for children admitted to a tertiary care paediatric hospital.
Methods: This was a retrospective audit of positive aerobic (AE) and anaerobic (AN) BC from paediatric inpatients with available TTP from 1 August 2016 to 2 January 2019.
Article Synopsis
- Multiple Omicron sub-lineages, particularly XBB and XBB.1.5, have become the global dominant variants, showcasing their ability to evade immunity despite minor genetic changes from previous variants.
- Researchers conducted a pseudovirus neutralization test with convalescent sera from individuals who recovered from SARS-CoV infections, including various Omicron subvariants.
- The findings showed no significant cross-neutralization among the different strains, suggesting that current SARS-related coronaviruses should be classified into three distinct serotypes.
Introduction: Information on the quality of health of children and younger persons (CYPs) after SARS-COV-2 infection remains scarce, especially from Asia. In this study, we utilised an online survey to investigate Long COVID prevalence in CYPs in Singapore.
Method: The study was an anonymised online survey of physical and functional symptoms, made available from 14 October 2022 to 15 January 2023.
Background: Hybrid immunity to SARS-CoV-2, resulting from both vaccination and natural infection, remains insufficiently understood in paediatric populations, despite increasing rates of breakthrough infections among vaccinated children.
Methods: We conducted a prospective longitudinal study to investigate the magnitude, specificity, and cytokine profile of antigen-specific T cell responses elicited by breakthrough SARS-CoV-2 infection in a cohort of mRNA-vaccinated children (n = 29) aged 5-11. This longitudinal analysis involved six distinct time points spanning a 16-month period post-vaccination, during which we analysed a total of 159 blood samples.
In studies of infectious disease prevention, the level of protective efficacy of medicinal products such as vaccines and prophylactic drugs tends to vary over time. Many products require administration of multiple doses at scheduled times, as opposed to one-off or continual intervention. Accurate information on the trajectory of the level of protective efficacy over time facilitates informed clinical recommendations and implementation strategies, for example, with respect to the timing of administration of the doses.
View Article and Find Full Text PDFBackground And Aims: There is a paucity of information on remdesivir (RDV) use in severe pediatric coronavirus disease 2019 (COVID-19). We aimed to explore the effectiveness of RDV as the cumulative proportion of pediatric COVID-19 patients deescalated from Day 5 of high dependency or intensive care unit (HD/ICU).
Methods: All children ≤18 years admitted to Singapore's largest pediatric hospital from January 1, 2020 to March 18, 2022 were reviewed retrospectively.
Article Synopsis
- Infants under 6 months are at a high risk of severe COVID-19, especially due to variants like Omicron (including XBB), but there's limited data on optimal maternal vaccination timing for safeguarding them.
- This study in Singapore examined the effects of maternal vaccination (before or during pregnancy) on the rates of SARS-CoV-2 infection in infants born between January and September 2022, focusing on those whose parents had COVID-19.
- Out of 7292 infants studied, the majority were born to vaccinated mothers, and while a small percentage were infected, the effectiveness of vaccination timing was an important factor in the overall analysis.
There is little information on BNT162b2 vaccine-induced variant-specific immunogenicity, safety data and dynamics of breakthrough infections in pediatric populations. We addressed these questions using a prospective two dose BNT162b2 (10 mcg) vaccination cohort study of healthy children 5-11 years in Singapore. Follow up included blood samples at scheduled visits, daily vaccination symptom diary and confirmation of SARS-CoV-2 infection.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates how well the BNT162b2 COVID-19 vaccine protects children and adolescents against omicron variants (BA.4, BA.5, and XBB), especially for those with previous infections.
- It involves a comprehensive analysis of national health data from Singapore, focusing on confirmed SARS-CoV-2 infections and vaccination histories among children aged 5-17, while excluding certain groups like immunocompromised individuals and those with multiple infections.
- Results are based on 135,197 participants, with researchers calculating the effectiveness of the vaccine through adjusted statistical methods to understand the protection levels conferred.
Combating a resurgence of poliomyelitis through public health surveillance and vaccination.
Ann Acad Med Singap
January 2023
Article Synopsis
- Poliomyelitis, or polio, can lead to permanent paralysis but is preventable through vaccination; Singapore has been polio-free since 2000.
- While wild polioviruses types 2 and 3 were eradicated globally in 2015 and 2019, resurgence of vaccine-derived poliovirus (VDPV) cases was noted in countries like Israel and the US in late 2022.
- To sustain global eradication and prevent outbreaks, high vaccination coverage is crucial, with Singapore maintaining 96% coverage among 1-year-olds, and enhanced surveillance strategies are recommended for early detection of poliovirus transmission.
Introduction: Multisystem inflammatory syndrome in children (MIS-C) is a rare inflammatory syndrome with multisystem involvement affecting children exposed to COVID-19. This condition is rarely reported in East Asia and was not detected in Singapore until 2021. We present 12 cases of MIS-C diagnosed in KK Women's and Children's Hospital (KKH) from October 2021 to December 2021.
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- A study evaluated the effectiveness of universal antigen rapid tests (ART) in preventing COVID-19 spread among hospitalized children aged 5 and older during the Omicron wave.
- Out of 444 hospitalized pediatric patients, ART showed a high accuracy with 93.7% agreement with PCR tests, and sensitivity of 83.3% and specificity of 97.5%.
- Findings suggested that while ART screening could help limit COVID-19 outbreaks in hospitals, its effectiveness is enhanced when combined with clinical symptoms and exposure assessment.
Article Synopsis
- - The study aimed to create and test a predictive model that assesses the likelihood of children with COVID-19 developing severe or critical symptoms, using data from five pediatric hospitals in Asia.
- - Researchers analyzed registry data from 1,147 COVID-positive patients to identify factors like age, comorbidities, and symptoms that increase or decrease the risk of severe illness.
- - The model showed strong predictive ability, with high accuracy rates in both training and validation tests, indicating it could help estimate risk in hospitalized children, but further validation is needed for clinical application.
Protective efficacy of vaccines and pharmaceutical products for prevention of infectious diseases usually vary over time. Information on the trajectory of the level of protection is valuable. We consider a parsimonious, non-linear and non-monotonic function for modelling time-varying intervention effects and compare it with several alternatives.
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- A country-specific method was developed to calculate the COVID-19 vaccination coverage needed for herd immunity by analyzing factors like age demographics, contact patterns, and vaccine effectiveness.
- * The study found that vaccinating adults aged 60+ has minimal impact on reducing transmission rates (R), largely because they have fewer social contacts compared to younger populations.
- * Achieving herd immunity is challenging without additional measures for highly transmissible variants, such as booster shots or vaccinating children, especially when vaccine effectiveness is lower than 95%.
Background: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory infection in young children. We previously estimated that in 2015, 33·1 million episodes of RSV-associated acute lower respiratory infection occurred in children aged 0-60 months, resulting in a total of 118 200 deaths worldwide. Since then, several community surveillance studies have been done to obtain a more precise estimation of RSV associated community deaths.
View Article and Find Full Text PDFThere is a scarcity of population-level data of pediatric COVID-19 infection from Southeast Asia. This study aims to describe and compare epidemiological, clinical, laboratory and outcome data among pediatric COVID-19 cases versus controls in two neighboring countries, Singapore and Malaysia. We used a test-negative case-control study design recruiting all suspected COVID-19 cases (defined by either clinical or epidemiological criteria) from January 2020 to March 2021 admitted to two main pediatric centers in Singapore and Malaysia.
View Article and Find Full Text PDFPediatric Kawasaki Disease Trends Prior to and During COVID-19 Outbreak in Singapore.
J Pediatric Infect Dis Soc
August 2021
Kawasaki disease (KD, typical/atypical/partial) admissions (n = 644) were surveyed from 2017 to 2020 and compared to urinary tract infection (UTI) admissions and COVID-19 in 2020. KD admissions decreased by 27% and median KD age decreased in 2020, whereas UTI admissions remained steady. KD admissions showed a seasonality with a peak in April and nadir in February-March.
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- This study investigates COVID-19 infection in children across Southeast and South Asia, focusing on identifying risk factors for severe disease through data from the Pediatric Acute and Critical Care COVID-19 Registry.
- The research includes 260 confirmed cases from eight hospitals in seven countries, revealing common symptoms like fever and cough, with about 40% of cases being asymptomatic and a low overall mortality rate of 2.3%.
- Key risk factors for severe or critical COVID-19 cases in children were found to be being under one year old, having underlying health issues, and presenting with a cough; further research is suggested to explore reasons behind variations in mortality across different regions.
An accurate depiction of the convalescent COVID-19 immunome will help delineate the immunological milieu crucial for disease resolution and protection. Using mass cytometry, we characterized the immune architecture in patients recovering from mild COVID-19. We identified a virus-specific immune rheostat composed of an effector T (T) cell recall response that is balanced by the enrichment of a highly specialized regulatory T (T) cell subset.
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