A PROSPECTIVE STUDY ON DETECTION, SUBTYPE ANALYSIS, CHARACTERIZATION, MOLECULAR EPIDEMIOLOGY AND TRANSMISSION OF INFLUENZA VIRUSES AMONG UNIVERSITY STUDENTS AND STAFF IN SINGAPORE

Abstract

A prospective surveillance study was conducted at the University health and wellness centre (UHC), National University of Singapore (NUS), to characterize influenza viruses circulating on campus from 2007-09. Nasopharyngeal swabs, clinical information and demographic data were collected from 510 students and staff with ILIs. Influenza virus (32.8%) was identified as the main causative agent followed closely by adenovirus (32.4%), rhinovirus (10.6%), enterovirus (7%), coronavirus (3.4%), parainfluenza virus (1.4%), respiratory syncytial virus (1.4%) and human metapneumovirus (1%). Fever (p<0.0001), chills (p<0.0001), aches (p<0.0002), running nose (p<0.0009) and cough (p<0.0062) were predictive of influenza. Phylogeographic analysis provided a strong evidence of geographical clustering based on faculty, Life-Sciences versus Non-life Sciences (AI P=0.02; PS P=0.05) and residence, on-campus versus off-campus (AI P=0.009; PS P=0.04). Integration of molecular and epidemiological methods for surveillance may guide public authorities to identify foci of transmission in localized communities.