Benign human enterovirus becomes virulent in selenium‐deficient mice

Coxsackieviruses have been implicated as possible co‐factors in the etiology of the selenium (Se)‐responsive cardiomyopathy known as Keshan disease. Here we report that a cloned and sequenced amyocarditic coxsackievirus B3 (CVB3/0), which causes no pathology in the hearts of Se‐adequate mice, induces extensive cardiac pathology in Se‐deficient mice. CVB3/0 recovered from the hearts of Se‐deficient mice inoculated into Se‐adequate mice induced significant heart damage, suggesting mutation of the virus to a virulent genotype. We demonstrate the important role of host nutritional status in determining the severity of a viral infection. © 1994 Wiley‐Liss, Inc.