Papers by Natalie W H Tan
Authorea (Authorea), Oct 28, 2022
Introduction Pediatric oncology patients are reportedly at risk for progression to severe Coronav... more Introduction Pediatric oncology patients are reportedly at risk for progression to severe Coronavirus disease-2019 (COVID-19) infection. Data on the safety and clinical effectiveness of remdesivir in children with cancer remains scarce. The main aims of this study were to describe COVID-19 infection in this cohort and to evaluate the utility of remdesivir treatment in terms of the time to viral clearance and its safety profile. Methods This was a retrospective observational cohort study of pediatric oncology patients [?]18 years of age with SARS-CoV-2 polymerase chain reaction (PCR) confirmed infection. Patients were admitted to KK Women's and Children's Hospital from 1 st November 2021 to 31 st March 2022. Clinical data, investigations and laboratory tests results were collected. Results Eighteen patients were included. Median age was 6.5 years (IQR: 4.64-9.83), and there were 13 males (72.2%). The immunosuppressive status of the cohort was: severe (n = 3, 22.2%), moderate (n = 9, 50.0%) and low (5, 27.8%). All patients had mild COVID-19 infection, and there were no COVID-19 attributed deaths. Remdesivir was initiated in four patients. We did not detect any benefit in terms of time to viral clearance or SARS-CoV2 PCR cycle threshold [?]25 between the treated versus non-treated groups. Remdesivir was well tolerated with no safety concerns. Conclusion Our cohort of immunocompromised pediatric oncology patients all had mild clinical COVID-19 with no directly attributable morbidity and mortality. In four patients, treatment with remdesivir was safe but did not lead to early viral clearance.
Journal of Microbiology Immunology and Infection, Apr 1, 2015
Journal of Paediatrics and Child Health, May 30, 2019
Introduction Pediatric oncology patients are reportedly at risk for progression to severe Coronav... more Introduction Pediatric oncology patients are reportedly at risk for progression to severe Coronavirus disease-2019 (COVID-19) infection. Data on the safety and clinical effectiveness of remdesivir in children with cancer remains scarce. The main aims of this study were to describe COVID-19 infection in this cohort and to evaluate the utility of remdesivir treatment in terms of the time to viral clearance and its safety profile. Methods This was a retrospective observational cohort study of pediatric oncology patients ≤18 years of age with SARS-CoV-2 polymerase chain reaction (PCR) confirmed infection. Patients were admitted to KK Women’s and Children’s Hospital from 1 November 2021 to 31 March 2022. Clinical data, investigations and laboratory tests results were collected. Results Eighteen patients were included. Median age was 6.5 years (IQR: 4.64 – 9.83), and there were 13 males (72.2%). The immunosuppressive status of the cohort was: severe (n = 3, 22.2%), moderate (n = 9, 50.0%)...
Frontiers in Immunology
An accurate depiction of the convalescent COVID-19 immunome will help delineate the immunological... more 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 (Teff) cell recall response that is balanced by the enrichment of a highly specialized regulatory T (Treg) cell subset. Both components were reactive against a peptide pool covering the receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein. We also observed expansion of IFNγ+ memory CD4+ T cells and virus-specific follicular helper T (TFH) cells. Overall, these findings pinpoint critical immune effector and regulatory mechanisms essential for a potent, yet harmless resolution of COVID-19 infection.
Annals of the Academy of Medicine, Singapore
Annals of the Academy of Medicine, Singapore
Journal of NeuroVirology, 2022
Journal of NeuroVirology, 2021
Human parechovirus (HPeV) is one of the most common causes of aseptic meningitis in children worl... more Human parechovirus (HPeV) is one of the most common causes of aseptic meningitis in children worldwide. This study aims to review the epidemiology, clinical presentation, and cerebrospinal fluid (CSF) findings in HPeV meningitis and compare these with Enterovirus (EV) meningitis. This is a retrospective study of children aged ≤ 1 year admitted for HPeV meningitis between November 2015 and July 2017, with positive CSF HPeV PCR and negative blood and CSF bacterial cultures. The clinical findings were compared with a historical cohort of children with EV meningitis admitted between July 2008 and July 2011. There were 71 children with HPeV meningitis, aged between 2 and 127 days, with the majority (96%) being ≤ 90 days old. The most common symptoms reported were poor feeding (42%), tachycardia out of proportion to fever (27%), and lethargy (20%). Only 2 patients (3%) had CSF pleocytosis. Cerebral spinal fluid white blood cell counts ranged from 0 to 28 cells/mm3, with a median of 3 cells/mm3 [interquartile range (IQR) 1-6 cells/mm3]. When compared to our historical cohort of EV meningitis ≤ 90 days old, children with HPeV meningitis ≤ 90 days old were less likely to have CSF pleocytosis (OR 0.008, 95% CI 0.001-0.057). HPeV and EV meningitis are known to cause sepsis-like illness in infants < 90 days old. This study further supports this, with the requirement for fluid bolus therapy for tachycardia or poor perfusion noted to be higher in children with HPeV meningitis ≤ 90 days old (OR 6.3, 95% CI 2.7-14.2).
Journal of the Pediatric Infectious Diseases Society, 2021
Kawasaki disease (KD, typical/atypical/partial) admissions (n = 644) were surveyed from 2017 to 2... more 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. All KD/KD-related pediatric intensive care unit cases tested negative for COVID-19, and no multisystem inflammatory syndrome in children was found.
Annals of the Academy of Medicine, Singapore, 2020
Introduction: In this study, a comparison of clinical, epidemiological and laboratory parameters ... more Introduction: In this study, a comparison of clinical, epidemiological and laboratory parameters between symptomatic and asymptomatic children with SARS-CoV-2 infection was performed. Materials and Methods: Data from all children with laboratory confirmed SARS-CoV-2 infection admitted to KK Women’s and Children’s Hospital (KKH), Singapore, from January to May 2020 were analysed. Results: Of the 39 COVID-19 children included, 38.5% were asymptomatic. Household transmission accounted for 95% of cases. The presenting symptoms of symptomatic children were low-grade fever (54.2%), rhinorrhoea (45.8%), sore throat (25%), diarrhoea (12.5%) and acute olfactory dysfunction (5.4%). Children of Chinese ethnicity (37.5% vs 6.7%), complete blood count (45.8% vs 6.7%) and liver enzyme abnormalities (25% vs 7.7%) were more common in symptomatic versus asymptomatic children. All children had a mild disease course and none required oxygen supplementation or intensive care. Conclusions: The high prop...
Pediatric Infectious Disease Journal, 2020
Journal of Pediatric Neurology, 2020
Parechovirus-A (PeV-A) and Enterovirus (EV) commonly cause childhood aseptic meningitis. Bacteria... more Parechovirus-A (PeV-A) and Enterovirus (EV) commonly cause childhood aseptic meningitis. Bacterial meningitis in children has been associated with devastating long-term sequelae. However, developmental outcomes are unclear in Parechovirus meningitis. This study aims to review the clinical findings and developmental outcomes of infants with PeV-A and EV meningitis. We performed a retrospective study of infants aged 90 days or younger being admitted to our hospital with PeV-A meningitis between November 2015 and July 2017, with positive cerebrospinal fluid (CSF) PeV-A PCR and negative blood and CSF bacterial cultures. Hearing and neurodevelopmental outcomes were compared with a previous cohort of infants aged 90 days or younger with EV meningitis admitted from January 2015 to December 2015. A total of 161 infants were included in our study, of which 68 infants (42.2%) had PeV-A meningitis and 93 infants (57.8%) had EV meningitis. We assessed their developmental outcome at 6 months, 1 ...
Global Pediatric Health, 2020
Background. Tuberculosis (TB) remains a major cause of mortality and morbidity globally. Pediatri... more Background. Tuberculosis (TB) remains a major cause of mortality and morbidity globally. Pediatric patients are more likely to develop severe disease. Abdominal TB is a rare manifestation of pediatric TB and can present with chronic and nonspecific abdominal symptoms. This study examines the clinical profile of pediatric patients with abdominal TB and treatment outcomes. Method. A retrospective study of patients admitted to a tertiary pediatric hospital in Singapore over 10 years. Clinical characteristics and outcomes were examined. Results. There were 3 male and 3 female patients with mean age of 11.3 years. Household contacts were traced in 3 cases. The most common presenting symptoms were fever, weight loss, and abdominal symptoms such as diarrhea, vomiting, and loss of appetite. Inflammatory markers were raised with mean C-reactive protein (CRP) and erythrocyte sedimentation (ESR) rate at 70.9 mg/L and 90 mm/h respectively. Abdominal imaging showed abnormalities such as splenic ...
BMJ Paediatrics Open, 2018
BackgroundTuberculosis (TB) is a major cause of mortality and morbidity in the world. Each case r... more BackgroundTuberculosis (TB) is a major cause of mortality and morbidity in the world. Each case represents ongoing transmission and has a significant public health burden. We aim to examine the clinical profile of paediatric TB and compare pulmonary TB (PTB) with extrapulmonary TB (EPTB) in Singapore.MethodsA retrospective study of patients admitted to KK Women’s and Children’s Hospital, Singapore from January 2008 to September 2017 with active TB was undertaken. The clinical characteristics and outcomes of patients with PTB and EPTB were compared.ResultsSeventy-five patients were diagnosed as having active TB (49 (65%) with PTB and 26 (35%) with EPTB). Patients with EPTB were more likely than those with PTB to be younger (median age 5.1 (IQR 1.2–10.2) years vs 10.1 (IQR 3.5–13.5) years), immunodeficient (35% vs 6%), with a lower haemoglobin count (median 11.2 (IQR 10.2–11.9) g/dL vs 12.0 (IQR 10.5–13.9) g/dL), lower recovery rate (27% vs 57%) and required longer duration of treatme...
Clinical Infectious Diseases, 2020
A well 6-month-old infant with coronavirus disease 2019 (COVID-19) had persistently positive naso... more A well 6-month-old infant with coronavirus disease 2019 (COVID-19) had persistently positive nasopharyngeal swabs up to day 16 of admission. This case highlights the difficulties in establishing the true incidence of COVID-19, as asymptomatic individuals can excrete the virus. These patients may play important roles in human-to-human transmission in the community.
Influenza and Other Respiratory Viruses, 2019
IntroductionIn tropical Singapore, influenza occurs all year‐round. This study of influenza‐confi... more IntroductionIn tropical Singapore, influenza occurs all year‐round. This study of influenza‐confirmed hospitalized pediatric patients compared clinical characteristics and complications by age‐group and differences between influenza A and B.MethodsThis was a retrospective study of pediatric inpatients from January 2013 to December 2014. Patients were grouped into: <6 months, 6 months to <5 years, 5‐ to <10‐year and ≥10 years. Complications were classified into neurologic, pulmonary, and other. We also calculated the incidence of hospitalized influenza cases per 100 000 age‐related population.ResultsThere were a total of 1272 patients with a median age of 37 months. The highest hospitalization rates were in the <6 months age‐group. Majority (75.2%) had no comorbidity; 25.6% had complications: neurologic 11.9%, pulmonary 9.6%, other 4.1%. Patients with other complications were older, male, and had the highest influenza B rates and the longest length of stay. Influenza A co...
Global Pediatric Health, 2018
Introduction. Rabies is one of the most deadly infectious disease. We present a challenging case ... more Introduction. Rabies is one of the most deadly infectious disease. We present a challenging case of an adverse reaction following rabies vaccine in a child. Case Summary. A 10-year-old girl was bitten by a stray dog in Bali and was prescribed rabies post-exposure prophylaxis. She developed breathlessness, abdominal cramps, and lips and eyes swelling 30 minutes after the second dose of rabies vaccine. The subsequent vaccine was successfully administered as a graded challenge with premedication. The final dose was administered in entirety under close observation. She developed transient hypotension 30 minutes later, which spontaneously resolved. Conclusion. There were multiple challenges in the care of this pediatric patient who was potentially exposed to rabies and experienced systemic adverse events during the course of post-exposure prophylaxis. A thorough clinical assessment should be made to weigh benefits versus risks of proceeding with rabies vaccination, bearing in mind that t...
Open Forum Infectious Diseases, 2018
peritonsillar abscess, deep neck abscess, subdural empyema, Lemierre's syndrome, and Pott's puffy... more peritonsillar abscess, deep neck abscess, subdural empyema, Lemierre's syndrome, and Pott's puffy tumor. Based upon medical records review and ICD-10 codes, patients were included in this study if they had a head or neck infection and reported a positive rapid influenza diagnostic test within 30 days preceding hospital admission. Results. We identified 44 patients with head or neck infections, of which 6 patients met inclusion criteria (table). The male-to-female ratio was 5:1 and the median age was 11.6 years (range 1.7-13.9 years). Most patients were diagnosed with influenza during a period of high influenza activity and the median time from influenza diagnosis to hospital admission was 4.5 days (range 1-6 days). One patient had received seasonal influenza vaccination. Patients had a wide range of infections, including orbital cellulitis (3), retropharyngeal abscess (2), and 1 of each of the following: Lemierre's syndrome, peritonsillar abscess, Pott's puffy tumor, and subdural empyema; 4 also had sinusitis. A causative pathogen was established in four cases: methicillin-resistant Staphylococcus aureus, Streptococcus anginosus group, S. pyogenes, and S. intermedius. The median duration of hospitalization was 22 days (range 5-35 days) and treatment duration ranged from 3.5 to 6 weeks. All patients completed antibiotic treatment successfully and had favorable outcomes. Conclusion. We suggest that complicated bacterial head and neck infections may represent an under recognized co-infection or secondary complication of infection with influenza virus, further stressing the importance of prevention and treatment of influenza infection.
Open Forum Infectious Diseases, 2018
Conclusion. Continuous monitoring of the quality of contact precautions showed excellent overall ... more Conclusion. Continuous monitoring of the quality of contact precautions showed excellent overall adherence correlating with a very low in-hospital transmission of MDROs, encouraging monitoring as an integrated part of contact precautions. Disclosures. All authors: No reported disclosures.
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Papers by Natalie W H Tan