About the Authors
Environmental Health Institute, National Environment Agency, Singapore, Singapore
Communicable Disease Centre, Tan Tock Seng Hospital, Singapore, Singapore
The authors have declared that no competing interests exist.
Conceived and designed the experiments: GY LCN. Performed the experiments: GY KYP YLL. Analyzed the data: GY YLL HCH LCN. Contributed reagents/materials/analysis tools: HCH LKT. Wrote the paper: GY. Conceptualized and coordinated the study: LCN. Prepared the manuscript: LCN. Coordinated sample collection from the hospital: AC YSL. Coordinated sample collection and diagnostics: LKT. Isolated the viruses: LKT.