The disease, rare in the United States but highly contagious and potentially serious, has now infected at least eight people in Orange County and more than a dozen statewide.
It causes fever, rash, cough and red, watery eyes. Those infected are contagious from about four days before the rash appears through four days after.
Orange County health officials added two new locations where the public could have been exposed. They are Spectrum Pharmacy at 18 Endeavor in Irvine on Jan. 7 between 2 p.m. and 3 p.m. and Target Store Starbucks and Pharmacy at 3750 Barranca Parkway in Irvine between 8:40 a.m. and 10 a.m. on Jan. 6.
Other locations of potential exposure are:
• The emergency department at St. Joseph Hospital on Dec. 30 between 6 p.m. and 11:30 p.m.
• Quest Diagnostics Laboratory on Jan. 3 between 12 p.m. and 1:15 p.m.
• CHOC Children's Hospital fourth floor between 3:40 p.m. on Jan. 1 and 12:45 p.m. on Jan. 2.
• CHOC Children's Hospital's emergency department on Jan. 4 from 10:25 a.m. to 12:50 p.m. and on Jan. 5 from 8:25 a.m. to 12:40 p.m.
The reappearance of measles after officials documented its elimination as a native disease in 2000 has fueled widespread concern. From Jan. 1 through Nov. 29 last year, measles cases numbered 610 in 24 states, a record high since its elimination. The majority of cases are in unvaccinated people.
In the previous six cases, three were unvaccinated children -- all old enough to be vaccinated -- who contracted measles between Dec. 15 and Dec. 20 at Disneyland, said Orange County Health Care Agency spokeswoman Nicole Stanfield.
Three others are adults; one was unvaccinated, one was partially vaccinated and one was fully vaccinated. None of the adults was hospitalized, Stanfield said.
Officials stressed that the best way to prevent infection is to get vaccinated. Children should get their first vaccination between 12 and 15 months of age, with a second dose between 4 and 6 years old before going to school, they said.