Four cases of a virus that can cause severe respiratory illness in infants and young children — especially those with asthma — have been found in California, state health officials announced Thursday.

Officials confirmed three cases of enterovirus D68 in San Diego County and one in Ventura County.

The illnesses marked California’s first 2014 cases of a virus known to have infected 153 people in 18 U.S. states, according to statistics posted by the federal Centers for Disease Control and Prevention earlier Thursday.

Officials at the California Department of Public Health did not immediately disclose details about the patients, though state health officer Dr. Ron Chapman said his staff was testing other specimens from patients around the state and expected more cases in the coming weeks.


“We are not surprised to find EV-D68 causing some illnesses in California given the apparent widespread nature of this virus in other parts of the country,” he said, in a statement.

Enterovirus D68 can cause symptoms similar to a cold or flu, but can result in severe respiratory illness in children with a history of asthma.