A5043552255- Infection Control and Ventilation
- Respiratory viral infections research
- COVID-19 epidemiological studies
- Influenza Virus Research Studies
- COVID-19 and healthcare impacts
- Viral gastroenteritis research and epidemiology
- SARS-CoV-2 and COVID-19 Research
- SARS-CoV-2 detection and testing
- Animal Disease Management and Epidemiology
- Coronary Artery Anomalies
- Animal Virus Infections Studies
- COVID-19 and Mental Health
- COVID-19 impact on air quality
- Congenital heart defects research
- Virus-based gene therapy research
- Viral Infections and Vectors
- Congenital Heart Disease Studies
- Osteomyelitis and Bone Disorders Research
- Indoor Air Quality and Microbial Exposure
- Hematological disorders and diagnostics
- Orthopedic Infections and Treatments
- Herpesvirus Infections and Treatments
- Particle Dynamics in Fluid Flows
- Air Quality and Health Impacts
- Inhalation and Respiratory Drug Delivery
University of Maryland, College Park
2022-2025
National University of Singapore
2020-2024
Duke-NUS Medical School
2018-2024
University of Toledo
2017
Children's Healthcare of Atlanta
2013
Emory University
2009-2013
Abstract Understanding the particle size distribution in air and patterns of environmental contamination SARS-CoV-2 is essential for infection prevention policies. Here we screen surface samples from hospital rooms COVID-19 patients RNA. Environmental sampling conducted three airborne isolation (AIIRs) ICU 27 AIIRs general ward. 245 are collected. 56.7% have at least one contaminated. High touch shown ten (66.7%) out 15 first week illness, (20%) beyond illness ( p = 0.01, χ 2 test). Air...
Abstract Background Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) superspreading events suggest that aerosols play an important role in driving the disease 2019 (COVID-19) pandemic. To better understand how airborne SARS-CoV-2 transmission occurs, we sought to determine viral loads within coarse (>5 μm) and fine (≤5 produced when breathing, talking, singing. Methods Using a G-II exhaled breath collector, measured RNA emitted by COVID-19 patients during 30...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks variants on shedding are not well understood.
Abstract Understanding the particle size distribution in air and patterns of environmental contamination SARS-CoV-2 is essential for infection prevention policies. We aimed to detect surface study associated patient-level factors. 245 samples were collected from 30 airborne isolation rooms COVID-19 patients, sampling was conducted 3 rooms. Air detected PCR-positive particles sizes >4 µm 1-4 two rooms, which warrants further transmission potential SARS-CoV-2. 56.7% had at least one...
Abstract Background Multiple SARS-CoV-2 superspreading events suggest that aerosols play an important role in driving the COVID-19 pandemic. However, detailed roles of coarse (>5μm) and fine (≤5μm) respiratory produced when breathing, talking, singing are not well-understood. Methods Using a G-II exhaled breath collector, we measured viral RNA emitted by patients during 30 minutes 15 singing. Results Among 22 study participants, 13 (59%) detectable levels aerosols, including 3...
During April and May 2020, we studied 20 patients hospitalized with coronavirus disease 2019 (COVID-19), their hospital rooms (fomites aerosols), close contacts for molecular culture evidence of severe acute respiratory syndrome 2 (SARS-CoV-2). Among >400 samples, found virus in most sample types, especially the nasopharyngeal (NP), saliva, fecal but prevalence positivity among fomites aerosols was low. The agreement between NP swab saliva high (89.5%; κ = 0.79). Two swabs collected from on...
The large livestock operations and dense human population of Southeast Asia are considered a hot-spot for emerging viruses.To determine if the pathogens adenovirus (ADV), coronavirus (CoV), encephalomyocarditis virus (EMCV), enterovirus (EV), influenza A-D (IAV, IBV, ICV, IDV), porcine circovirus 2 (PCV2), rotaviruses A C (RVA RVC), aerosolized at animal-interface, humans working in these environments carrying viruses their nasal airways.This cross-sectional study took place Sarawak,...
As a leading global city with high population density, Singapore is at risk for the introduction of novel biological threats. This has been recently reinforced by human epidemics in SARS coronavirus, 2009 pandemic H1N1 influenza A virus, and enterovirus 71. Other major threats to include MERS-coronavirus various avian swine viruses. The ability quickly identify robustly track such initiate an early emergency response remains significant challenge. In effort enhance respiratory virus...
Abstract Influenza contributes significantly to childhood morbidity and mortality. Given the magnitude of school-aged child population, a sizeable proportion influenza virus transmission events are expected occur within school settings. However, activity in schools is not well-understood, likely due our limited ability accurately monitor for respiratory viruses without disrupting environment. In this study, we evaluated use bioaerosol sampling method noninvasively detect quantify airborne A...
Abstract Background Aerosol inhalation is recognized as the dominant mode of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Three highly transmissible lineages evolved during pandemic. One hypothesis to explain increased transmissibility that natural selection favors variants with higher rates viral aerosol shedding. However, extent shedding successive SARS-CoV-2 unknown. We aimed measure infectivity and rate into exhaled breath (EBA) by individuals Delta Omicron...
Abstract Background: Understanding the extent of aerosol-based transmission severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important for tailoring interventions control disease 2019 (COVID-19) pandemic. Multiple studies have reported detection SARS-CoV-2 nucleic acid in air samples, but only one study has successfully recovered viable virus, although it limited by its small sample size. Objective: We aimed to determine shedding aerosols from COVID-19 patients. Methods: In...
As the world transitions to COVID-19 endemicity, studies focusing on aerosol shedding of highly transmissible SARS-CoV-2 variants concern (VOCs) are vital for calibration infection control measures against VOCs that likely circulate seasonally. This follow-up Gesundheit-II sampling study aims compare patterns Omicron VOC samples with pre-Omicron analyzed in our previous study.Coarse and fine from 47 patients infected were collected during various respiratory activities (passive breathing,...
Abstract Background The relative importance of inhalation, spray, and touch transmission remains poorly understood. We implemented a randomized controlled trial incorporating community-acquired cases using behavioral, personal protective equipment, environmental interventions as tools to understand the pathway influenza transmission.Figure 1.Study design timeline cohorts with naturally infected Donors Methods recruited healthy volunteer Recipients PCR-confirmed infection hotel quarantine....
Objectives/Goals: Mathematical models of airborne virus transmission lack supporting field and clinical data such as viral aerosol emission rates infectious doses. Here, we aim to measure inhalation exposure influenza aerosols in a room shared with persons community-acquired estimate the dose via inhalation. Methods/Study Population: We recruited healthy volunteer recipients donors polymerase chain reaction (PCR)-confirmed infection. On admission hotel quarantine, provided sera determine...
Background The relative importance of influenza transmission via inhalation (airborne), direct deposition (spray), and contact (touch) remains poorly understood. We implemented a controlled human virus infection trial to study pathways. Methods established quarantine hotel with individual rooms for participants recruited healthy Recipients two-week cohort stays. Donors community-acquired infection, confirmed by qRT-PCR. interacted in room limited ventilation humidity. collected ambient...
Abstract Background In recent years, Vietnam has suffered multiple epizootics of influenza in poultry. Methods From 10 January 2019 to 26 April 2021, we employed a One Health surveillance approach at live bird markets (LBMs) and swine farms Northern Vietnam. When the COVID-19 pandemic permitted, each month, field teams collected oral secretion samples from poultry pigs, animal facility bioaerosol fecal samples, worker nasal washes 4 LBMs 5 across sites. Initially were screened with molecular...
Abstract Background SARS-CoV-2 epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks variants on shedding are not well understood. Methods We recruited COVID-19 cases to give blood, saliva, mid-turbinate fomite (phone) swabs, 30-minute breath samples while vocalizing into a Gesundheit-II, with without at up two visits days apart. quantified sequenced viral RNA, cultured virus, assayed sera for anti-spike anti-receptor binding domain antibodies. Results...
Abstract Far-UVC (222 nm UV-C light) is a promising tool to mitigate aerosol transmission of pathogens indoors. However, recent studies have raised concerns related ozone (O 3 ) production and secondary chemistry. In this study, we measured indoor O ultra-fine particle (UFP, 17.5-289 nm) concentrations with without 222 far-UVC (average fluence rate 1.7-1.8 µW/cm 2 in hotel quarantine facility Baltimore (MD, USA). We obtained nearby outdoor from the Environmental Protection Agency (EPA)...
Approximately one-third of individuals with 22q11.2 deletion syndrome (22q11DS), a common genetic disorder highly associated intellectual disabilities, may develop schizophrenia, likely preceded by mild to moderate cognitive decline.We examined adolescents and young adults 22q11DS for the presence executive function deficits using modified version Wisconsin Card Sorting Test (MCST) assessed whether specific performances were concurrent schizophrenia-prodrome symptoms. We also possible...
Newly emergent and virulent strains of H7N9 avian influenza virus are rapidly spreading in China threaten to invade Vietnam. We sought introduce aerosol sampling for viruses During October 2017, National Institute Occupational Safety Health 2-stage samplers were assembled on a tripod run 4 hours. Concomitantly, up 20 oropharyngeal (OP) swab samples collected from chickens ducks distanced at 0.2–1.5 m each sampler. The 3 weeks yielded 30 that 90% positive A, by quantitative...
A number of serious human adenovirus (HAdV) outbreaks have been recently reported: HAdV-B7 (Israel, Singapore, and USA), HAdV-B7d (USA China), HAdV-D8, -D54, -C2 (Japan), HAdV-B14p1 (USA, Europe, HAdV-B55 (China, France).To understand the epidemiology HAdV infections in we studied 533 HAdV-positive clinical samples collected from 396 pediatric 137 adult patients Singapore 2012 to 2018. Genome sequencing phylogenetic analyses were performed identify genotypes, clonal clusters, recombinant or...
There is an increasing body of evidence suggesting that transmission respiratory viruses occurs through the inhalation virus-laden particles. Our study describes use aerosol sampling system to monitor prevalence airborne in a hospital setting. Using SKC AirCheck Touch pumps, with National Institute for Occupational Safety and Health (NIOSH) bioaerosol samplers filter cassette blanks, 28 samples were collected ward Singapore. Following DNA/RNA extraction, real-time RT-PCR/PCR was used...