One of our colleagues noticed that virtually every Washington Post article concerning the measles outbreak is followed by comments that link the outbreak to illegal immigration. As it turned out, a number of prominent politicians have suggested that there might be a link — or that a link cannot be ruled out. (LePage did not mention measles, but suggested there could be in “uptick” in other diseases.)

Our friends at PundiFact noted that Rush Limbaugh flat-out declared the outbreak was linked to “our immigration policy,” earning the commentator a “Pants on Fire.” But the politicians’ statements were much more nuanced and careful. What kind of evidence do they have?

There are two key issues. Where is the measles outbreak coming from? And how well screened are illegal immigrants such as unaccompanied children?

The 2015 outbreak, mostly centered at Disney amusement parks in California, is still under investigation. Anne Schuchat, director of the Centers for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases, told reporters on Jan. 29 that the “genotype of the virus that’s associated with the Disneyland outbreak is causing outbreaks in 14 different countries around the world.” She specifically mentioned Indonesia, India and Dubai as possible sources that were under investigation, but she emphasized that “we assume that someone got infected overseas, visited the parks and spread the disease to others.”

In other words, an American brought the disease back, not that an illegal immigrant brought it in.

The 2014 outbreak was traced to the Philippines, specifically from members of the Amish community in Ohio who had traveled there as missionaries; the community had halted routine vaccinations many years ago after a baby was suspected of getting ill from a shot. In 2014, the Philippines had a measles outbreak, with some 50,000 cases. After the church group came back from the trip, the disease “spread like wildfire” through the community.

The Philippines and India are on a top 10 list of sources of illegal immigrants, but about three-quarters of all illegal immigrants come from just four countries — Mexico, El Salvador, Guatemala and Honduras. And it turns out that these countries have pretty good records on immunization rates.

Here’s how the countries compare to the United States over the four most recent years of data, according to the World Health Organization:

United States: 92 percent (2010); 92 (2011); 92 (2012); 91 (2013)

Mexico: 95 (2010); 98 (2011); 99 (2012); 89 (2013)

El Salvador: 92 (2010); 89 (2011); 93 (2012); 94 (2013)

Guatemala: 93 (2010); 89 (2011); 93 (2012); 85 (2013)

Honduras: 98 (2010); 95 (2011); 93 (2012); 89 (2013)

As you can see, in most years, the other countries had better vaccination rates than the United States, though there was a sudden decline in 2013 in every country but El Salvador. Still, these are fairly high vaccination rates, making it much less likely that illegal immigrants from these countries are a source of the outbreak.

Brooks, in an interview, emphasized that he “never made a statement” that there was a link, just that it was possible. “You can have a lively debate about the most probable source of the outbreak,” he said, but he said he has made no judgment about whether illegal immigrants are a source. “I certainly think it is a concern,” he added.

Brooks acknowledged that the immunization rates in the countries that are the biggest source of illegal immigrants are good, “but anything less than 100 percent immunization” means that there is still a possible link. He pointed to the declines suffered by Mexico, Honduras and Nicaragua in 2013_and also noted that Haiti, another source of illegal immigrants, has only a 65 percent rate.

Brooks cited a 2012 CDC report on 212 measles cases in 2011, which showed that 90 percent were associated with importations from other countries. Only 72 cases (36 percent) could be specifically linked to travel to or from overseas; 52 were linked to U.S. residents who had traveled abroad, and 20 were linked to foreign visitors. (France had a major outbreak that year, and 13 cases were traced just to it.) The report does not state whether any of the importations were linked to illegal immigrants; the only cases involving the Americas were from Canada (one) and the Dominican Republic (one).

We should note that CDC’s Schuchat said that in 2014, “79 percent of the unvaccinated cases of measles in the U.S. were unvaccinated due to personal belief exceptions.” So even if one could trace the source to an illegal immigrant, the main source of the problem is a failure to get vaccinated in the first place.

Terry Giles, campaign chairman for the nascent Ben Carson presidential campaign, emphasized that Carson used the word “perhaps’ in his comments. “Non-compliance is anyone who has not been vaccinated,” he said in an e-mail. “While the unaccompanied children entering the U.S. from Central and Latin America (we have all heard about) are being screened and you have some good information regarding Latin America, we cannot possibly know how many Mexican and other children are crossing the border that are not vaccinated.”

“Does all of that create a risk — yes,” Giles said. “But does that mean the measles outbreak is an ‘immigration’ issue — no. It may be a another reason we should be sealing our borders — but the non-vaccination of American children because of misunderstood or misleading information would still create a potential public health issue even if we reduced the flow of illegal immigrants to zero.”

The CDC has stated that “children arriving at U.S. borders pose little risk of spreading infectious diseases to the general public.” The agency says that unaccompanied children may have missed some vaccinations so “as a precaution, ORR [Office of Refugee Resettlement] is providing vaccinations to all children who do not have documentation of previous valid doses of vaccine.”

Lauren Vandiver, spokeswoman for Brooks, provided an Inspector General report from the Department of Homeland Security that reported that some of the unaccompanied children had spread diseases:

“DHS employees reported exposure to communicable diseases and becoming sick on duty. For example, during a recent site visit to the Del Rio USBP Station and Del Rio Port of Entry, (Customs and Border Protection) CBP personnel reported contracting scabies, lice, and chicken pox. Two CBP Officers reported that their children were diagnosed with chicken pox within days of the CBP Officers’ contact with a UAC (unaccompanied alien child) who had chicken pox. In addition, USBP personnel at the Clint Station and Santa Teresa Station reported that they were potentially exposed to tuberculosis.”

LePage’s office did not respond to queries. Maine Department of Health and Human Services Commissioner Mary Mayhew told the Sun Journal that LePage was trying to make a point about the lack of health screenings for immigrants who arrived in this country illegally. Mayhew said the state did not have comprehensive data on any health dangers this caused.

Unlike Limbaugh, Brooks and Carson did not draw a direct link between illegal immigration and the measles outbreak; they merely suggested it is a possibility. But it’s a tricky balance, given that thus far the CDC has not traced this most recent outbreak — or previous ones — to illegal immigration. One cannot have 100 percent certainty in life, and so that always leaves open the possibility of a link.

Brooks’ comments were stronger, even suggesting the possibility of deaths, while Carson’s remarks were relatively nuanced. To some extent, this falls in the realm of opinion. Nevertheless, when raising the possibility that illegal immigration could spread disease, politicians also have an obligation to note that the evidence of any such link, thus far, is rather slim or even nonexistent.

Sun Journal State Politics Editor Scott Thistle contributed to this report.

“This is the problem with some of the illegals that are here today. When a refugee comes here from a foreign country, they get a medical assessment and we know their health. But when they are here illegally, they don’t get medical assessments. And one thing that we don’t want to see is the uptick in hepatitis C, HIV and tuberculosis, but it is here. We are dealing with it. And it is very costly.”

Maine Gov. Paul LePage, R, State of the State address, Feb. 3

 • • •

• CHRIS CUOMO: “Do you believe that what we’re seeing with measles coming back again is because of noncompliance by families with their kids and vaccines?”
• BEN CARSON: “A combination of noncompliance and introduction into our society of people who perhaps haven’t been well-screened.”
• CUOMO: “That sounds like code for illegal immigration to me. Is that a point you’re trying to make? Are you trying to make the measles situation into an immigration argument?”
• CARSON: “It’s not code and I’m not trying to make it into any particular argument. I’m stating what the facts are.”

exchange on CNN, Feb. 4

 • • •

“I don’t think there is any health care professional who has examined the fact, who can honestly say that Americans have not died because of the diseases brought into America by illegal aliens who are not properly healthcare screened as lawful immigrants are. It might be the enterovirus 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.”

Rep. Mo Brooks, R-Ala., interview on the Matt Murphy radio show, Feb, 3, 2015

Proposed legislation

A bill introduced by a Democratic lawmaker would eliminate the philosophical exemption that allows parents to skip vaccinations for their children. A separate proposal backed by Democrats aims to make getting exemptions more difficult.

That bill would require parents to consult with a medical professional about the risks and benefits of vaccines and obtain a signed form if they wish to opt out for non-medical reasons.

Another measure, introduced by Republicans, would create a vaccine safety office in Maine’s Center for Disease Control and Prevention that would offer parents guidance on the risks of vaccines. Committee hearings have not yet been held on the bills.