Since the late summer, the United States and Canada have experienced an outbreak of enterovirus D68 (EV-D68) that has been linked to severe respiratory illness, including several deaths.
In the US, the number of confirmed cases topped 1,000, according to the latest Centers for Disease Control and Prevention (CDC) data. From mid-August to October 27, 2014, CDC or state public health laboratories have confirmed a total of 1,035 people in 47 states and the District of Columbia with respiratory illness caused by EV-D68. Only Nevada, Alaska and Hawaii have yet to report a confirmed case.
Of the more than 2,000 specimens the CDC has assayed, about half have tested positive for EV-D68, and about a third have tested positive for a different enterovirus or a rhinovirus.
The federal health agency says EV-D68 has been detected in specimens from eight patients who died and had samples submitted for testing.
North of the border in Canada, confirmed cases have been reported in British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, New Brunswick, Nova Scotia and Prince Edward Island. As of October 16, 2014, a total of 150 specimens, collected from across Canada between August and October 2014, had tested positive for EV-D68 at the NML.
On October 16, 2014 the BCCDC confirmed that a young man who died earlier that week had contracted EV-D68. The patient had a history of severe asthma and was in the hospital when he developed respiratory failure.
The current outbreak in Canada began on September 15, 2014, when Alberta Health Services reported 18 cases of EV-D68 among hospitalized patients under the age of 18. Nine cases were among children admitted to a Calgary children’s hospital, with a diagnosis of asthma or bronchiolitis between September 1 and September 11, 2014.
Six outbreaks have been reported in the previous five years (Philippines, 2008, 21 confirmed cases; Japan, 2010, ≥120 confirmed cases; Netherlands, 2009, 24 confirmed cases; Georgia, USA, 2009, 6 confirmed cases; Pennsylvania, USA, 2009, 28 confirmed cases; Arizona, USA, 2010, 5 confirmed cases).
Typically, enteroviruses have circulated with summer-fall seasonality in temperate climates.
Outbreaks of enterovirus diseases have usually occurred in several-year cycles. EV-D68 outbreaks have usually occured within or later than the typical enterovirus season.