Recently several conservative politicians and pundits tried linking the current measles outbreak in the U.S. to immigrants. Rush Limbaugh said that the children coming across the southern U.S. border "were never examined after they got here and quarantined if they had the disease" and that "many of them had measles." Republican Congressman Mo Brooks said the disease was brought into the country by "illegal aliens."
Blaming immigrants for spread of disease is not a new concept in the U.S. and like previous spurious claims, this latest attempt holds no water.
The measles outbreak that began in Disneyland in December has continued to make headlines, and it remains unclear exactly who the first case was and where they brought the disease from. There is no doubt that it would be a significant problem if there were many unvaccinated children crossing our borders sick with any number of diseases. But that is not what is happening.
When referring to illegal immigrants, the implication is individuals from Mexico, or one of the other Central or South American countries. However, Mexico had zero cases of measles in 2013 and only 2 confirmed cases in 2014. They also have a vaccine rate for measles that is as good or better than ours in no small part because their vaccine policy is universal, free, and mandatory. In fact more than 100 countries worldwide do a much better job at vaccinating their children than we do, including many in Central and South America. The probability that the disease originated there from either a legal or illegal immigrant and was imported here is low.
Instead, to understand the resurgence of vaccine preventable diseases in the U.S., we need to look closer to home. Unlike Mexico, the U.S. does not have a federal mandate for vaccines. Although all 50 states require up-to-date vaccines for all children entering school, all but Mississippi and West Virginia permit nonmedical exemptions. These exemptions are not the necessary ones for children with certain diseases or allergies. Rather, parents invoke them simply because they "don't want to" vaccinate their children for whatever reason. When nonmedical exemptions increase, so do the number of kids who get sick from vaccine preventable diseases. Fortunately, California lawmakers introduced new legislation to end personal exemptions for vaccination. But that still leaves 47 states where a parent's personal preference trumps the safety of the entire country.
In the U.S., wealthy families are more likely to take the personal exemption to skip standard vaccine schedules and are also more likely to have the means to travel the world for vacations. According to the CDC, most imported cases of measles come from Europe, "a popular destination for U.S. travelers and an area where measles continues to circulate." The current U.S. outbreak, while impressive by U.S. historical measures, pales in comparison to the impact the disease has worldwide. In fact, careful genetic analysis of the measles virus responsible for the current outbreak in the U.S. suggests it matches that of the virus causing 14 different outbreaks worldwide. It could have come from almost anywhere and most likely found its way into the U.S. through an unvaccinated U.S. tourist traveling abroad, or tourists from regions with high endemic disease, rather than illegal immigrants.
There is no doubt that migrants can carry diseases. Asylum seekers from Bosnia and Herzegovina, as well as Serbia may be to blame for the current measles outbreak in Germany since the first cases were detected in that population. However, in the case of the largest outbreak in the U.S. last year, the CDC tracked it to unvaccinated Amish missionaries who traveled to the Philippines and brought measles back to their largely unvaccinated friends and neighbors. Fortunately many of the Amish families in that community lined up to get their children vaccinated, and the outbreak eventually petered out. Without a similar aggressive approach to stem the current outbreak, we may see a dramatic increase in the numbers of measles cases in 2015 like we saw in 2014.
Blaming the current outbreak on illegal immigrants, developing new immigration laws, or proposing better enforcement of existing laws will do nothing to prevent diseases like measles from gaining access to the U.S. again. Viruses do not care about borders and can hitch a ride with a tourist, or even the air of a plane. We can't keep our borders sealed from infectious diseases like measles, but we can protect ourselves, and our society, by doing a better job of vaccinating all children who can be vaccinated.