For every public health scare, there's someone ready to blame it on immigrants. Cue up Rep. Mo Brooks (R-AL), who told radio host Matt Murphy that unauthorized immigrants might be responsible for the measles outbreak, because their home countries weren't "blessed with the kind of health care, the kind of immunizations that we have in the United States."

Via Think Progress:

Rep. Mo Brooks (R-AL) was asked by the host whether he saw any correlation between immigration and the measles outbreak that has erupted in the United States... Said Brooks: "It might be the introvirus that has a heavy presence in Central and South America that has caused deaths of American children over the past 6 to 9 months. It might be this measles outbreak. There are any number of things." Lest one thinks Brooks is heartless on the subject of immigration, he implores listeners that "You have to have sympathy for the plight of the illegal aliens" who "have not been blessed with the kind of health care, the kind of immunizations that we demand of our children in the United States."

Brooks' sympathy is misplaced. The countries from which most unauthorized immigrants come — Mexico and Central America — have childhood immunization programs. Mexico, in fact, has a 99 percent vaccination rate — which handily beats the US' 92 percent. Even assuming that unauthorized immigrants are disproportionately likely to be poor in their home countries and therefore less likely to be vaccinated, the odds are pretty good that immigrants from Mexico (or the "northern triangle" of Central America, where the vaccination rate is 93 percent) have gotten their shots.

Furthermore, of course, most unauthorized immigrants have been in the US for years. But Brooks went on to cast aspersions on long-resident unauthorized immigrants, too, claiming that unauthorized immigrant children who went to public schools "to some degree" weren't subject to the schools' vaccination requirements. This idea appears to come from the fact that some schools don't subject homeless children to vaccination requirements, so it's not technically untrue (insofar as some unauthorized children might be homeless) — but it's more misleading than not. Children who have homes, and go to school, are required to be vaccinated regardless of their immigration status. (Never mind that for most Republicans, talking about vaccination "mandates" is the quickest way to polarize the issue.)

But look. Fear of diseases crossing invisibly into the US housed by immigrants is a fear older than unauthorized migration itself. Even before most immigrants who came to the US were allowed to enter, before the restrictions of the early 20th century, immigrants had to pass a health screening and were rejected if they carried any disease. In the 1990s, fear of AIDS shaped America's immigration policy toward Haiti. And in recent years, public-health scares from swine flu (also known as "Mexican flu"), to Ebola, to swine flu again, have been used as reasons to "secure the border."

The spike in measles cases in 2014 was caused by an encounter between an American and a non-American. But it was the American who carried the disease back to the States.