Enterovirus D68, also known as EV-D68, belongs to a larger group of viruses known as enteroviruses. This group includes more than 100 different types of enteroviruses, which together affect millions of people around the world. Enteroviruses commonly affect the gastrointestinal tract and cause stomach flu and diarrhea. However, EV-D68 is mainly associated with respiratory disease and therefore is more similar to the human rhinovirus (a type of virus that affects the respiratory tract).
EV-D68 was first identified in California in 1962 in 4 children with pneumonia and bronchiolitis (a type of infection of the airways). Until recently, only a few isolated cases had been identified since that time, but in the past 5 years outbreaks have occurred in Japan, the Philippines, the Netherlands, the United States and Canada.
Enterovirus D68 infections occur most frequently in summer and fall. Children under the age of 5 and children with asthma appear to be the most at risk of infection, but it can also affect adults with asthma and those that have weakened immune systems.