Enterovirus D68 Infections Associated with Severe Respiratory Illness in Elderly Patients and Emergence of a Novel Clade in Hong Kong.
Despite the recent emergence of enterovirus D68 (EV-D68), its clinical impact on adult population is less well defined. To better define the epidemiology of EV-D68, 6,800 nasopharyngeal aspirates (NPAs) from 2010-2014 were subject to EV-D68 detection by RT-PCR and sequencing of 5'UTR and partial VP1. EV-D68 was detected in 30 (0.44%) NPAs from 22 children and 8 adults/elderlies. Sixteen patients (including five elderly) (53%) had pneumonia and 13 (43%) patients were complicated by small airway disease exacerbation. Phylogenetic analysis of VP1, 2C and 3D regions showed four distinct lineages of EV-D68, clade A1, A2, B1 and B3, with adults/elderlies exclusively infected by clade A2. The potentially new clade, B3, has emerged in 2014, while strains closely related to recently emerged B1 strains in the United States were also detected as early as 2011 in Hong Kong. The four lineages possessed distinct aa sequence patterns in BC and DE loops. Amino acid residues 97 and 140, within BC and DE-surface loops of VP1 respectively, were under potential positive selection. EV-D68 infections in Hong Kong usually peak in spring/summer, though with a delayed autumn/winter peak in 2011. This report suggests that EV-D68 may cause severe respiratory illness in adults/elderlies with underlying co-morbidities.
Department of Microbiology, The University of Hong Kong, Hong Kong, China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.|Research Centre of Infection and Immunology The University of Hong Kong, Hong Kong, China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
Susanna K P
SK
Lau
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Cyril C Y
CC
Yip
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Pyrear Su-Hui
PS
Zhao
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Wang-Ngai
WN
Chow
Department of Microbiology, The University of Hong Kong, Hong Kong, China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.|Research Centre of Infection and Immunology The University of Hong Kong, Hong Kong, China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
Kelvin K W
KK
To
Department of Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China.
Alan K L
AK
Wu
Department of Microbiology, The University of Hong Kong, Hong Kong, China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.|Research Centre of Infection and Immunology The University of Hong Kong, Hong Kong, China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
Kwok-Yung
KY
Yuen
Department of Microbiology, The University of Hong Kong, Hong Kong, China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.|Research Centre of Infection and Immunology The University of Hong Kong, Hong Kong, China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.
Patrick C Y
PC
Woo
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D030016:Enterovirus D, Human / Q000145:classification* / Q000235:genetics; D004769:Enterovirus Infections / Q000453:epidemiology / Q000821:virology*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000821:virology*; D012621:Seasons; D017423:Sequence Analysis, RNA; D014481:United States