Susanna K P Lau1, Pyrear S H Zhao2, Siddharth Sridhar3, Cyril C Y Yip2, Kam Leng Aw-Yong2, Elaine Y Y Chow2, Kelvin C M Cheung2, Rex W H Hui2, Ryan Y H Leung2, Yuki S K Lai2, Alan K L Wu4, Kelvin K W To3, Patrick C Y Woo5, Kwok-Yung Yuen3. 1. Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, China; State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. Electronic address: skplau@hku.hk. 2. Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, China. 3. Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, China; State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. 4. Department of Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China. 5. Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, China; State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. Electronic address: pcywoo@hku.hk.
Abstract
BACKGROUND: Coxsackievirus A6 (CV-A6) represents the predominant enterovirus serotype in Hong Kong, but its epidemiology in our population was unknown. OBJECTIVES: To examine the clinical and molecular epidemiology of CV-A6 and detect emerging recombinant strains in Hong Kong. STUDY DESIGN: Nasopharyngeal aspirates (NPAs) from patients with febrile or respiratory illness were subject to RT-PCR for CV-A6 and sequencing of 5'-NCR and VP1. CV-A6-positive samples were further subject to 2C and 3D gene sequencing. Complete genome sequencing was performed on potential recombinant strains. RESULTS: Thirty-six (0.35%) NPAs were positive for CV-A6 by 5'-NCR RT-PCR and sequencing, 28 of which confirmed by partial VP1 gene sequencing. Among the 28 patients (mainly young children) with CV-A6 infection, hand-foot-and-mouth disease (HFMD) (43%), herpangina (18%) and tonsillitis (11%) were the most common diagnoses. Seven (25%) patients had neurological manifestations, including febrile seizures, encephalitis and meningitis. VP1 gene analysis showed that 24 CV-A6 strains circulating in Hong Kong belonged to genotype D5, while 4 strains belonged to D4. Further 2C and 3D gene analysis revealed eight potential recombinant strains. Genome sequencing of five selected strains confirmed four recombinant strains: HK459455/2013 belonging to recombination group RJ arisen from CV-A6/CV-A4, HK458288/2015 and HK446377/2015 representing novel group RL arisen from CV-A6/CV-A4, and HK462069/2015 representing novel group RM arisen from CV-A6/EV-A71. Recombination breakpoints located at 3D were identified in the latter three recombinant strains, with HK462069/2015 (from a child with encephalitis) having acquired 3D region from EV-A71. CONCLUSIONS: We identified novel recombinant CV-A6 strains in Hong Kong, with 3D being a common recombination site.
BACKGROUND:Coxsackievirus A6 (CV-A6) represents the predominant enterovirus serotype in Hong Kong, but its epidemiology in our population was unknown. OBJECTIVES: To examine the clinical and molecular epidemiology of CV-A6 and detect emerging recombinant strains in Hong Kong. STUDY DESIGN: Nasopharyngeal aspirates (NPAs) from patients with febrile or respiratory illness were subject to RT-PCR for CV-A6 and sequencing of 5'-NCR and VP1. CV-A6-positive samples were further subject to 2C and 3D gene sequencing. Complete genome sequencing was performed on potential recombinant strains. RESULTS: Thirty-six (0.35%) NPAs were positive for CV-A6 by 5'-NCR RT-PCR and sequencing, 28 of which confirmed by partial VP1 gene sequencing. Among the 28 patients (mainly young children) with CV-A6 infection, hand-foot-and-mouth disease (HFMD) (43%), herpangina (18%) and tonsillitis (11%) were the most common diagnoses. Seven (25%) patients had neurological manifestations, including febrile seizures, encephalitis and meningitis. VP1 gene analysis showed that 24 CV-A6 strains circulating in Hong Kong belonged to genotype D5, while 4 strains belonged to D4. Further 2C and 3D gene analysis revealed eight potential recombinant strains. Genome sequencing of five selected strains confirmed four recombinant strains: HK459455/2013 belonging to recombination group RJ arisen from CV-A6/CV-A4, HK458288/2015 and HK446377/2015 representing novel group RL arisen from CV-A6/CV-A4, and HK462069/2015 representing novel group RM arisen from CV-A6/EV-A71. Recombination breakpoints located at 3D were identified in the latter three recombinant strains, with HK462069/2015 (from a child with encephalitis) having acquired 3D region from EV-A71. CONCLUSIONS: We identified novel recombinant CV-A6 strains in Hong Kong, with 3D being a common recombination site.