That is because virtually every public health expert says there isn’t any evidence that this is the case.
“There is no evidence to show that migrants are spreading disease,” Dr. Paul Spiegel, who directs the Center for Humanitarian Health at Johns Hopkins School of Public Health told journalist Maggie Fox of NBC News. “That is a false argument that is used to keep migrants out.”
The U.S. Centers for Disease Control’s Division of Global Migration and Quarantine works with U.S. Customs and Border Protection to monitor people who may be entering the U.S. with an infectious disease. Physicians working with border officials may conduct medical screenings of immigrants, refugees and asylum seekers. If a person seeking admittance to the U.S. is determined to have one of nine communicable infectious diseases (such as tuberculosis, yellow fever or pandemic flu), among others, the U.S. can deny admittance and/or quarantine the individual.
There is also a specific disease surveillance infrastructure between the U.S. and Mexico border, called the Binational Border Infectious Disease Surveillance Program. Agents screen people for HIV, measles, pertussis, rubella, rabies, hepatitis A, influenza, tuberculosis, shigellosis, syphilis, Mycobacterium bovid infection, brucellosis and food-borne diseases, according to Politifact. The only disease outbreak found among undocumented minors from Central America during a 2104 immigration surge was scabies, the story said.
In fact, cases of disease outbreaks caused by people crossing U.S. borders have more often been caused by Americans harboring pathogens acquired overseas. For example, one of the worst most recent outbreaks of measles was caused in 2014 by an American missionary who brought the disease back from the Philippines to an Ohio Amish community. The U.S. had virtually eliminated measles in the U.S. by 2000, but the disease has come back as pockets of people have declined to vaccinate their children. Measles is caused by a virus. Symptoms include rash, fever and cough and the virus can cause blindness, pneumonia, encephalitis and complications in pregnancy.
“What we’ve seen — since the epidemic of measles was interrupted in 2000 — is that we are continually getting measles coming in from overseas,” Jane Seward, former deputy director of the viral diseases division at the CDC, told Belluz in 2015. “More often than not, it’s US residents who go overseas for a trip — to say, Europe, where they don’t think they need to be vaccinated. They bring measles back.”
For journalists who are looking for resources to debunk this link between immigration and infectious diseases, this new tip sheet offers contact information for some experts on the topic and links to recent stories.