An epidemiological surveillance of hand foot and mouth disease in paediatric patients and in community: A Singapore retrospective cohort study, 2013-2018.

Affiliation

Min N(1), Ong YHB(1), Han AX(2), Ho SX(1), Yen EWP(3), Ban KHK(4), Maurer-Stroh S(2)(5), Chong CY(3), Chu JJH(1)(6).
Author information:
(1)Laboratory of Molecular RNA Virology and Antiviral Strategies, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
(2)Protein Sequence Analysis Group, Bioinformatics Institute, Agency for Science, Technology and Research
(A*STAR), Singapore, Singapore.
(3)Infectious Disease Service, Department of Pediatrics, KK Women's and Children's Hospital, Singapore, Singapore.
(4)Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
(5)Department of Biological Sciences
(DBS), National University of Singapore
(NUS), Singapore, Singapore, Singapore.
(6)Collaborative and Translation Unit for HFMD, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research
(A*STAR), Singapore, Singapore.

Abstract

BACKGROUND: While hand, foot and mouth disease (HFMD) is primarily self-resolving-soaring incidence rate of symptomatic HFMD effectuates economic burden in the Asia-Pacific region. Singapore has seen a conspicuous rise in the number of HFMD cases from 2010s. Here, we aims to identify the serology and genotypes responsible for such outbreaks in hospitals and childcare facilities. METHODS: We studied symptomatic paediatric HFMD cases from 2013 to 2018 in Singapore. Surveillance for subclinical enterovirus infections was also performed in childcares at the same time period. RESULTS: Genotyping 101 symptomatic HFMD samples revealed CV-A6 as the major etiological agent for recent outbreaks. We detected infections with CV-A6 (41.0%), EV-A71 (7%), CV-A16 (3.0%), coxsackievirus A2, CV-A2 (1.0%) and coxsackievirus A10, CV-A10 (1.0%). Phylogenetic analysis of local CV-A6 strains revealed a high level of heterogeneity compared against others worldwide, dissimilar to other HFMD causative enteroviruses for which the dominant strains and genotypes are highly region specific. We detected sub-clinical enterovirus infections in childcare centres; 17.1% (n = 245) tested positive for enterovirus in saliva, without HFMD indicative symptoms at the point of sample collection. CONCLUSIONS: CV-A6 remained as the dominant HFMD causative strain in Singapore. Silent subclinical enteroviral infections were detected and warrant further investigations.