Recombinant Coxsackievirus A2 and Deaths of Children, Hong Kong, 2012

Cyril C.Y. Yip, Susanna K.P. Lau, Patrick C.Y. Woo, Samson S.Y. Wong, Thomas H.F. Tsang, Janice Y.C. Lo, Wai-Kwok Lam, Chak-Chi Tsang, Kwok-Hung Chan, and Kwok-Yung Yuen

Author affiliations: The University of Hong Kong, Hong Kong, China (C.C.Y. Yip, S.K.P. Lau, P.C.Y. Woo, S.S.Y. Wong, K.-H. Chan, K.Y. Yuen); Department of Health, Hong Kong (T.H.F. Tsang, J.Y.C. Lo, W.-K. Lam, C.-C. Tsang)

Abstract

A natural recombinant of coxsackievirus A2 was found in 4 children with respiratory symptoms in Hong Kong, China, during the summer of 2012. Two of these children died. Vigilant monitoring of this emerging recombinant enterovirus is needed to prevent its transmission to other regions.

Human coxsackieviruses belong to the family Picornaviridae and genus Enterovirus. These viruses are divided into groups A and B on the basis of their pathogenicity in suckling mice (flaccid paralysis caused by group A viruses and spastic paralysis caused by group B viruses) (1). Human infections with enteroviruses such as coxsackievirus A (CVA) are generally mild, but severe complications were more often reported for infections caused by enterovirus 71 (EV71) (1,2). We report infection of 4 children with recombinant coxsackievirus A2 in Hong Kong.

The Study

On June 10, 2012, a previously healthy 4-year-old boy in Hong Kong had fever, cough, and rhinorrhea. His condition deteriorated rapidly and he lost consciousness. He was admitted to Pamela Youde Nethersole Eastern Hospital in Hong Kong, cardiac asystole developed, and he died <4 hours after admission. Autopsy showed areas of dull red consolidation on the upper lobes of the lungs. Postmortem histologic examination showed focal areas of alveolar damage and hyaline membrane formation with lymphocytic infiltrates. There were no gross or histologic changes indicative of myocarditis or encephalitis in any part of his brain, including the brainstem.
Tissue samples of heart, lung, spleen, and rectum, and nasopharyngeal and rectal swab specimens were positive for enterovirus by virus culture in a rhabdomyosarcoma cell line. These samples were also positive by reverse transcription PCR (RT-PCR) with pan-enterovirus primers (5′-CAAGCACTTCTGTBWCCCCGG-3′ and 5′-GAAACACGGACACCCAAAGTAGT-3′) specific for the 5′ untranslated region (5′-UTR) as described (3–5).