The number of confirmed California cases of enterovirus D-68 has risen to 14, public health officials announced Friday.
All the cases affected children between 1 and 15 years of age. In Southern California, two cases were in Los Angeles County, one was in Riverside County and another was in Ventura County, according to the state Department of Public Health.
The arrival of the virus has been much slower in the state relative to the rest of the country, where at least 500 cases have been confirmed. The virus has been associated, rarely, with severe breathing troubles and, even more rarely, with neurological symptoms, including polio-like muscle weakness.
Only one California case this year has involved partial paralysis: a child currently being treated at Children's Hospital Los Angeles.
Gil Chavez, the state epidemiologist, said he expects more cases to be discovered across the state, but "we are pleased that the number of confirmed cases is not growing as rapidly as it is elsewhere."
State health officials advised parents to seek medical attention immediately for children with breathing difficulty. They also advised washing hands often, especially after changing diapers, and avoiding touching eyes, nose and mouth with unwashed hands.
The season for the virus typically stretches from late summer to early fall.