Measles has broken out in California. On Friday, the California Department of Public Health confirmed 15 cases of measles in the state, compared to two at this time in 2013. Three were in Riverside County and another eight reported in Los Angeles and Orange counties. The ages of these 15 individuals range from 5 months to 44 years.

Since 2000, when measles was declared eliminated in the United States, the number of annual cases had declined substantially. In 2005, California recorded only four measles cases, the lowest number ever. The number of California measles cases has ranged from four to 40 annually, according to Dr. Gil Chavez, deputy director of the Center for Infectious Diseases at the California Department of Public Health.

“Unfortunately, we are off to a very bad start in 2014,” Chavez said. “The cases have occurred throughout California. At this time last year, we had only recorded two cases … We expect to see many more cases unless people take precautionary measures.”

Two of the county’s measles cases were linked to the initial case, according to Chief Barbara Cole, county’s Disease Control Branch. “For Riverside County, we usually have one or two cases annually. In some years, there are no cases.”

Because measles is highly contagious, Cole recommends parents who suspect their children may have contracted the disease to keep them at home and contact their health-care provider. Fever, cough and rash are the symptoms to be alert for, she added.

The measles vaccine has essentially eliminated the measles virus in the U.S., however, travelers to locations outside the U.S. may be exposed to the virus. Chavez said several of the cases could be traced to travelers to the Philippines, where a large outbreak is occurring, and two had traveled to India, where measles is endemic.

He encouraged anyone who has not to get the measles vaccine. Of the 15 confirmed cases at least seven were individuals who had filed personal belief exceptions against obtaining the vaccine.

Measles is a highly contagious viral disease spread through the air when someone who is ill with the disease coughs or sneezes. Symptoms begin with a fever that lasts for a couple of days, followed by a cough, a runny nose, red, watery eyes and rash. The rash typically appears first on the face, along the hairline and behind the ears, and then affects the rest of the body. Infected people are usually contagious for about eight days: four days before their rash starts and four days after.

Children are recommended to get their first dose of measles/mumps/rubella vaccine at 12 to 15 months old. The second dose of MMR is usually administered before children start kindergarten at ages 4 to 6. Immunized adults do not need boosters. However, anyone born since 1957 who has not had two doses of vaccine may still be vulnerable to measles and should ask their doctor about getting immunized.

Chavez stressed that there is no support to the theories that the vaccine is harmful or links it to long-term problems such as autism.

Measles places a burden on public health officials, especially in the local counties. Every measles case must be investigated and individuals who may have been exposed to the virus have to be contacted and warned.