Over 100 individuals in the U.S. are now confirmed to have been infected with measles with most of the cases associated with an outbreak that started at Disneyland in Southern California last December. The number of measles cases is now the second biggest in the U.S in at least the past 15 years.

Measles is a highly infectious respiratory disease that typically starts with a fever. Individuals infected with the viral disease eventually suffer from other symptoms including cough, red eyes and runny nose. Tiny red spots also appear starting at the head then spread to the rest of the body.

Sufferers particularly young children 5 years old and below and adults who are older than 20 years old are more likely to have measles-related complication such as diarrhea and ear infection. Severe complications may also occur such as pneumonia, encephalitis, or the swelling of the brain, which can cause convulsion, deafness and developmental problems.

Individuals who have at least two doses of the measles vaccine are considered 99 percent immune, says Anne Schuchat, CDC's National Center for Immunization and Respiratory Diseases director. Some parents, however, choose not to vaccinate their children.

Kelly McMenimen, from Marin County, Calif., for instance, chose not to have her son vaccinated because she does not want too many toxins entering her son's body.

On Friday, the White House told parents to take heed of the public health officials' advice  to get vaccinated against the viral disease. White House Press Secretary Josh Earnest said that although the President thinks it is still the parents' decision to have their children vaccinated, science suggests of the benefits of vaccination.

"I'm not going stand up here and dispense medical advice," Earnest said. "But I am going to suggest that the president's view is that people should evaluate this for themselves, with a bias toward good science and toward the advice of our public health professionals, who are trained to offer us exactly this kind of advice."

Figures from the California Department of Public Health show that at least 58 of the measles cases in California can be traced to the Disneyland cluster. Public health officials believe that outbreak started when an infected person from outside the U.S. went to Disneyland in Anaheim between Dec. 15 and Dec. 20.

Measles cases have also been confirmed in Oregon, Pennsylvania, South Dakota, Michigan, Arizona, Colorado, Illinois, Minnesota, Nebraska, New York, Texas, Utah and Washington state.