SAN DIEGO - San Diego's measles outbreak has spread aboard a planeload of passengers to Hawaii, where an 11-month-old baby infected in a Bird Rock medical clinic last month is recovering in isolation at an island military base.
Hawaiian health officials are trying to find about 250 passengers on the Hawaiian Airlines flight, especially children, who may have come in contact with the sick infant, said Dr. Wilma Wooten, San Diego County's public health officer.
"Children who have not been immunized are the ones we're most concerned about," Wooten said.
Health officials also are trying to find people who were at Lindbergh Field's Terminal 2, Gate 41 between 8:30 a.m. and 12:30 p.m. Saturday. That time period covers two hours before and after the 10:30 a.m. departure of Flight 15.
In less than a month, the outbreak - San Diego County's first since 1991 - began in Switzerland and has spanned about half the globe. The case demonstrates how quickly, extensively and silently the potentially lethal virus can spread.
"(It) speaks to the highly infectious nature of measles," Wooten said.
San Diego County health officials have confirmed measles in five patients, and they are investigating five suspected cases. All these children, from infants to a 9-year-old, were not vaccinated because they were younger than 1 - the minimum age for measles inoculation - or because their parents objected to having them vaccinated.
The health experts worry that hundreds of other individuals who may have contracted the virus will start to exhibit symptoms for weeks to come.
More than 30 officials in San Diego County are working into the night trying to notify parents of hundreds of potentially exposed children from at least five schools, programs and a clinic, Wooten said.
The affected sites include a day care center and swim school in the county's Pacific Beach area; a toddler program and a school in Clairemont; and a public charter school in Linda Vista.
Measles causes a high fever, cough, runny nose and watery eyes. A rash usually follows. Symptoms last for one to two weeks.
In the United States, measles can be fatal in up to three per 1,000 children who contract it. The death rates are higher in developing countries.
Children are more at risk of suffering complications, including pneumonia and swelling of the brain, than senior citizens. Most adults have been immunized by the measles vaccine or by getting measles when they were young.
The outbreak began when a 7-year-old returned from a family vacation in Switzerland on Jan. 15 infected with measles. More than 400 cases of measles occur in Switzerland each year, about triple the total in the United States.
The 7-year-old goes to the San Diego Cooperative Charter School in Linda Vista. The child set off a chain reaction that has infected two siblings, one of whom was a fellow charter student, and at least one classmate.
The 7-year-old's parents took the youngster to the Children's Clinic of La Jolla, on La Jolla Boulevard in Bird Rock, on Jan. 25. The child may have coughed and sneezed in the office, potentially infecting four other patients.
Those four patients returned to the clinic between Feb. 5 and 8, possibly spreading the virus to 60 other children.
One of the infants who became infected Jan. 25 at the clinic is the 11-month old whose family flew to Hawaii.
Another is a 10-month-old child who was hospitalized Friday with measles symptoms, but whose test results have not been confirmed. This baby went to the Baldwin Academy day care center and the Murray Callan Swim School, both in Pacific Beach.
A third child suspected of contracting measles Jan. 25 at the clinic is a 2-year-old who attended Alcott Elementary School's Infant & Toddler Development Program in Clairemont. On Feb. 6, the youngster also briefly visited the School of the Madeleine, also in Clairemont.
Dr. Alisa Lawrie, a pediatrician at the clinic, said one child now known to have measles came in with only a fever and had not developed the characteristic rash. Because measles is so rare now, she said, "there was nothing to indicate it was more serious. We thought he just had a viral illness and sent him home."
Lawrie said the outbreak should send a clear message to parents about the danger of not vaccinating their children.
"This could have been prevented if we had a fully vaccinated public," she said. "But there's a lot of misinformation about vaccines, and more and more parents are choosing not to vaccinate their children."
"Measles is very very contagious," said Dr. Stuart Cohen, a pediatrician and president-elect of the San Diego County Medical Society. "Kids under a year who haven't received the routine vaccination are at risk of getting sick, and that's what will happen if we start getting higher percentages of parents not vaccinating their children."
Under state law, parents can decline to have their children vaccinated based on medical, religious or personal reasons. Many have done so out of fear - which doctors say is unfounded - that the vaccine may cause autism. The vaccine does not contain thimerosal, a compound that some people link to autism.
Officials for the Baldwin Academy and the Callan swim school said they have been besieged with phone calls from the public. They are upset that health officials released the names of their businesses when they did nothing wrong.
Wooten emphasized that the schools and programs were not to blame.
"It is not a reflection of the care or level of service provided at these facilities," she said.
Measles was widespread in the United States before a vaccine was developed in the early 1960s. At that time, many parents would be grateful when their children got measles. The infection meant their children would be immunized for the rest of their lives.
Today, immunization rates throughout San Diego County average 1.6 percent in preschool students and 2.5 percent in kindergarteners, Wooten said.
Ten percent of the children at the San Diego Cooperative Charter School, where the 7-year-old who started the outbreak is a student, were not vaccinated. That's the highest percentage rate of unvaccinated students in the San Diego Unified School District, said district nurse Eileen Griffiths.
Students whose parents decline vaccination have been barred from returning to their schools or programs until Feb. 26, when health officials believe their risk of becoming infected or infecting others would have passed.