As the summer vacation season nears, measles cases are on the rise in California, driven by unimmunized travelers infected elsewhere who are entering the state, health officials said Friday.
"We see that as worrisome," Dr. Gilberto Chavez, deputy director of the California Department of Public Health, said in an interview.
Those infected with measles include not only unimmunized Californians traveling abroad, but foreign visitors to the state and others who simply came in contact with infected travelers, Chavez said.
Measles is considered eliminated in the Western Hemisphere, with very few cases of the illness here, but it is a significant problem in Europe, Asia and Africa.
A measles outbreak in Europe has spread through 30 countries, with 6,500 people infected so far this year. France has been hit the worst. In one hot spot in Belgium, the virus is hitting unimmunized children the hardest —- those whose parents don't believe in vaccinations and infants who have not yet been inoculated, according to the World Health Organization.
Measles is also spreading through India and the Philippines.
Although infants are traditionally given inoculations after they reach the age of 1, Chavez said infants who are traveling abroad can receive the measles vaccine as early as 6 months of age.
So far this year, 13 measles cases have been reported in California, with seven in April alone. Four patients have been hospitalized.
Health officials are concerned because measles can spread very quickly, especially if it takes root in a population of unvaccinated people.
In 2008, a 7-year-old boy triggered a measles outbreak in San Diego after he returned, infected, from a family trip to Switzerland. The boy infected his two siblings and nine other children at his public charter school and a doctor's office. His parents had chosen not to vaccinate him or his siblings. About 70 children had to be quarantined at home.
In other medical news, the disease whooping cough, also known as pertussis, still remains a problem in California. Although the number of cases has fallen from the height of the epidemic last year, the disease still remains at higher rates than normal, health officials said. Between January and mid-April, 733 people were infected. Last year, there were 9,273 cases, and 10 infants died.
Chavez reminded parents that a new state law will require middle and high school students to show proof that they have received the Tdap booster shot before entering school this fall. The shot protects against tetanus, diphtheria and pertussis.