Mexico, Canada and at least eight U.S. states have become the battleground for the measles outbreak as the number of confirmed cases has risen to 149.

Since the outbreak of measles began in December 2014 at Disneyland in Anaheim, California, reports have begun trickling in and have shown that cases are spreading. According to the Los Angeles Times, at least 123 cases have now been confirmed across 12 counties in California, with at least 39 of said cases tracing back to those who either worked at or visited Disneyland during the busy holiday season.

That's double the cases reported by the California Department of Public Health in late January. Meanwhile, seven other states have joined the ranks of places reporting measles cases, including Arizona, Colorado, Michigan, Nebraska, Oregon, Washington and Utah.

Mexico, meanwhile, has reported at least two known cases, while Canada has 10.

Some conservative political pundits, including controversial radio host Rush Limbaugh, have been blaming the measles outbreak on children who crossed the U.S.-Mexico border unauthorized over the previous summer as part of the migratory crisis that saw tens of thousands of unaccompanied children from Latin America emigrating to the United States. 

However, as Latin Post reported, health experts, including those who work with the U.S. Center for Disease Control and Prevention, have debunked that theory, stating many of the measles cases each year involve U.S-born Americans who had traveled abroad and back.

In addition, recent figures released from the World Health Organization showed neighboring Latin American countries have almost as good of -- if not better -- rates for measles vaccination as the U.S. While the U.S. has a 91 percent vaccination rate, Mexico and Honduras were not far behind with 89 percent, while Guatemala has an 85 percent vaccination rate and El Salvador topped all countries at 95 percent.

The CDC confirmed in January at least one case in Mexico belonged to an unvaccinated child who visited Disneyland in late December.