( CNN ) -- Enterovirus D68 is likely coming -- if it has n't already -- to a state near you . Since mid-August , the Centers for Disease Control and Prevention had confirmed 153 cases of respiratory illness caused by Enterovirus D68 in 18 states : Alabama , Colorado , Connecticut , Illinois , Indiana , Iowa , Kansas , Kentucky , Louisiana , Minnesota , Missouri , Montana , Nebraska , New Jersey , New York , Oklahoma , Pennsylvania and Virginia . The California Department of Health has confirmed four cases in patients in San Diego and Ventura counties . And `` in the upcoming weeks , more states will have confirmed cases of EV-D68 infection , '' the CDC said in a statement Wednesday . `` Several states are investigating clusters of people with severe respiratory illness , and specimens are still being tested for EV-D68 . It can take a while to test specimens and obtain lab results ... These increases will not necessarily reflect changes in real time , or mean that the situation is getting worse . '' Canadian health officials have confirmed three cases of Enterovirus D68 in British Columbia . A fourth suspected case from a patient with severe respiratory illness is still under investigation . Two of the confirmed cases are children between 5 and 9 , said Dr. Danuta Skowronski , lead epidemiologist on emerging respiratory viruses at the British Columbia Centre for Disease Control . The third is a teen between 15 and 19 . Enteroviruses are very common . The CDC estimates that 10 million to 15 million infections occur in the United States each year . These viruses usually appear like the common cold ; symptoms include sneezing , a runny nose and a cough . Most people recover without any treatment . But Enterovirus D68 seems to be exacerbating breathing problems in children who have asthma . The virus is hard to track as many enteroviruses cause similar symptoms and hospitals generally do not test for specific types . But health officials have asked doctors to send in samples if they suspect that Enterovirus D68 has caused a patient 's severe respiratory illness . Enteroviruses `` tend to have a summer-fall pattern , '' Skowronski said , so the high number of cases will likely subside over the next few months . What parents should know . In the meantime , parents should be on the lookout for the symptoms of Enterovirus D68 . Unfortunately , in the beginning it 's difficult -- if not impossible -- to tell the difference between a regular cold and this type of virus . But if your child develops a fever or a rash , or if he has difficulty breathing , seek medical attention right away . Children with asthma or a history of breathing problems are particularly susceptible for severe symptoms . CNN 's Jen Christensen , Matthew Stucker and Teri Genova contributed to this story .
NEW : Virus confirms 18 cases of Enterovius D68 in 18 states . Canada also confirmed four cases of EV-D68 . British Columbia confirms three cases in California . Virus worsens breathing problems for children who have asthma .