Between multiple public health agencies from the U.S. and Canada, at least 147 cases of measles have been documented between December 28, 2014 and February 19, 2015 in an outbreak that is believed to have started at California’s Disneyland theme park in mid-December. The outbreak has expanded to six other states, plus Mexico and Canada.

As debate continues to swirl around the issue of required school vaccinations and health risks of being vaccinated versus risking contracting the disease, California’s legislature is considering a bill that would close a perceived loophole in the vaccination requirement process.

Currently, California parents may sign a personal belief waiver, exempting their children from as many vaccinations as the parent determines acceptable. California is currently one of 19 states that allow a purely personal or religious basis for schoolchildren’s vaccination exemption according to the Santa Cruz Sentinel.

The Sentinel goes on to state that SB 277 would end any possibility for “personal belief exemptions.”

The first two months of 2015 have seen more cases than in at least 10 of the last 15 years in the United States, according to the Centers for Disease Control (CDC).

“Among the 110 California patients, 49 (45%) were unvaccinated; five (5%) had 1 dose of measles-containing vaccine, seven (6%) had 2 doses, one (1%) had 3 doses, 47 (43%) had unknown or undocumented vaccination status, and one (1%) had immunoglobulin G seropositivity documented, which indicates prior vaccination or measles infection at an undetermined time,” according to a California Department of Public Health (CDPH) release citing previously reported data as of February 11, 2015. As of February 18, 14 of the California cases were children under the age of one year and thus too young to be vaccinated.

“The source of the initial Disney theme park exposure has not been identified,” the release states, adding that that the number of cases appearing with the onset of a rash has been decreasing since the height of the spread in January.

Measles was considered eliminated in the United States in 2000 and in 1998 Canada determined the country free of endemic measles.

An additional ten cases have been reported in Quebec, Canada, the Public Health Department (PHD) of the Agency for Health and Social Services of Lanaudière reported as of February 11. On Thursday, Washington State reported a third case of the disease–this time in a 43-year-old man who was exposed at a Port Angeles clinic where an infected 52-year-old man who had contracted the disease was present, reported Q13 Fox KCPQ of Tacoma.

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