Researchers from Boston Children's Hospital and MIT linked the recent measles outbreak at Disneyland to poor vaccination rates in a study published on Monday, the Los Angeles Times reported.
The spread of the disease "shines a glaring spotlight on our nation's growing anti-vaccination movement and the prevalence of vaccination-hesitant parents," the team said in a study published in the journal JAMA Pediatrics.
The "index case" -- the person who introduced the disease into the park -- has not been identified. But according to NPR, state officials have confirmed 133 cases related to the outbreak since late last year.
According to the researchers, people exposed to the illness came from areas where the vaccination rate was between 50 and 86 percent. Typically, at least 96 percent of a community must be vaccinated for MMR (measles, mumps, rubella) in order to maintain herd immunity.
"Clearly, MMR vaccination rates in many of the communities that have been affected by this outbreak fall below the necessary threshold to sustain herd immunity, thus placing the greater population at risk as well," the study concluded.
Time magazine reported that the Disneyland outbreak is connected to all but 43 cases of U.S. measles infections as of March 13.
Last month, three California lawmakers introduced a bill that would strike down religious exemptions for vaccinating children.