EV-D68 is one of more than 100 enteroviruses, and belongs to the viruses of the family Picornaviridae genus Enterovirus.

The enterovirus is recognised to cause mild to severe respiratory illness ranging from fever, rhinorrhoea, cough and myalgia, to wheezing and difficulty breathing resulting in hospital and intensive care unit (ICU) admission. It has been associated with cases and clusters of polio-like neurological symptoms, including paralysis and meningo-encephalitis.

Historically, low numbers of EV-D68 have been detected annually in the UK. An increased number of cases have been reported from the USA and several other countries during 2014.

https://www.gov.uk/government/publications/enterovirus-d-68-risk-assessment