Rare enterovirus continues to circulate in North America

Abstract

A rare strain of enterovirus that can cause severe respiratory illness in children is circulating throughout the USA and Canada, causing a higher than usual number of infections. Between mid-August and Sept 26, 277 people in 40 states and the District of Columbia have tested positive for enterovirus D68, all but one of them children, reports the US Centers for Disease Control and Prevention (CDC) in Atlanta, GA. National numbers are not available for Canada, but the virus has been detected in several provinces, including Alberta, British Columbia, and Ontario, according to the Public Health Agency of Canada. There have been no reported deaths due to D68. D68 is a relatively uncommon strain of the non-polio enteroviruses, a group of about 100 viral strains related to the common cold. It can cause infl uenzalike symptoms, and in more severe cases wheezing and diffi culty breathing. It was fi rst identifi ed in 1962, but has been seen only infrequently since then—just 79 reported cases between 2005 and 2008, with a few clusters cropping up in the USA, Europe, and Asia between 2008 and 2010. Then, last month, clusters of children with severe respiratory illnesses in hospitals in Kansas City, MO, and Chicago, IL, tested positive for the strain. Since then, the CDC has prioritised testing of specimens from children with severe respiratory illness, and has found that about half of the cases were due to D68, with another third caused by other enteroviruses or related rhinoviruses. The numbers of positive tests are expected to climb as the CDC deals with a backlog of samples, but the agency cautions that any rise in the number of cases does not necessarily indicate that the virus is spreading.