Fox News hosts and guests have repeatedly warned the network’s audience in recent weeks that Congolese refugees crossing the U.S.-Mexico border may be carrying Ebola, despite statements to the contrary from health officials.

It’s commonplace for Fox to stoke bigoted fears about the dire consequences the purported immigrant “invasion” will have on viewers’ physical security and political power. But invoking Ebola carries particular risks given President Donald Trump’s obsession with the network’s coverage and his reaction to a prior outbreak of the virus in 2014. Every such segment carries with it the possibility that a watching Trump might see it and begin issuing tweets that would needlessly panic the public or demand federal actions that threaten lives.

In the summer and fall of 2014, Republican politicians and their right-wing media allies cynically deployed an Ebola outbreak in West Africa as a political weapon, denouncing President Barack Obama’s scientifically sound response and stoking public fears as a means of triumphing in the midterm elections.

Trump played a central role in this panic-for-profit scheme, using appearances on Fox News and his widely followed Twitter feed to urge the government to take actions that public health experts said would have had dire repercussions if they had been implemented. Trump’s commentary had a huge impact -- the White House’s Office of Digital Strategy concluded that his unhinged tweets “represented a turning point, the moment when fear of the deadly virus began to infect the American public.”

Obama’s actions were ultimately vindicated, but Trump’s entry into the political realm helped lay the groundwork for his successful presidential campaign two years later.

As president, Trump has been ultimately responsible for overseeing the federal government’s response to the second-largest outbreak of Ebola in history, which began last August in the Democratic Republic of Congo and has claimed more than 1,400 lives so far. This time around, there have been no Trump tweets on the subject, and Republicans and right-wing media have been largely uninterested in the disease, likely seeing little potential political gain in fearmongering about a potential pandemic when they control the executive branch.

But that’s beginning to change.

While the current outbreak has stretched on for more than a year, Fox’s biggest stars almost entirely ignored the story until earlier this month, after U.S. Customs and Border Protection began reporting that it had apprehended groups of central African migrants, including Congolese nationals, at the U.S.-Mexico border.

Those migrants are typically seeking asylum, citing “horrific stories of government-sanctioned violence at home.” Many are then taken to San Antonio, TX, which houses the closest major bus depot near their main point of entry to the U.S., from which they can travel to stay with family members while going through the asylum process. While it is unusual to see such a surge of Africans seeking asylum at the border, the Democratic Republic of Congo has been the largest source of refugees to the U.S. in each of the last three years.

It is not possible for the recently apprehended Congolese migrants to carry Ebola, as health officials have detailed. The migrants are not from the area of Congo that is experiencing the current outbreak. If they had been infected with Ebola, they would likely have died long before reaching the U.S., since the disease has a 21-day incubation period and is extremely debilitating. And if they had somehow managed to both catch Ebola and survive to reach the U.S. border, it would have been caught by the U.S. government medical personnel who screened them after being apprehended.

But Fox is deeply committed to terrifying its audience about the physical threat to their safety that undocumented immigrants supposedly bring. And so over the last few weeks, the network’s personalities -- particularly virulently anti-immigrant prime-time hosts Tucker Carlson and Laura Ingraham -- have repeatedly brought up the possibility of Ebola infection in discussing the migrants.

In denouncing the U.S.’s lax borders on June 3, Carlson echoed right-wing websites like Gateway Pundit and Conservative Review in arguing that the Congolese migrants were particularly dangerous. “Across the world, it is now common knowledge that if you can make it to our border, odds are you will never have to go back,” he said. “And by the way, there's an Ebola outbreak happening in Congo right now. Maybe it isn't a great idea to let people from there enter our country illegally.”

On Carlson’s program two nights later, conservative commentator Tammy Bruce similarly warned that “chaos” on the border threatened “American families and their health” because of the apprehension of migrants from Congo, which “is dealing with another outbreak of Ebola.”

As the week went on, conspiracy theorist websites like The Gateway Pundit and Infowars began suggesting without evidence that Ebola-infected immigrants were roaming the streets of San Antonio. On June 10, that theory made it all the way to Ingraham’s Fox show.

“Hundreds of illegals from the Congo apparently are applying for asylum and being deposited in San Antonio,” she said. “Now, this could clearly be a public health concern. Why? Well, according to Reuters, the number of cases of Ebola in eastern Congo has passed 2,000.”

Ingraham went on to acknowledge that city officials had told her that it was impossible for the migrants to be carrying Ebola, citing its incubation period. But then she mocked their response: “I don't know, why would we even put that to chance? I'm not sure we're really tracking the travel patterns of everybody coming into the country, but they're telling us, ‘Don't worry tonight. It's OK.’"

She connected the Congolese refugees to Ebola again in two different segments on Friday, during which she and one of her guests stated that the situation is worrisome even though the incubation period makes it unlikely that the migrants are actually carrying the disease.  

Fox continued to link the central African migrants to the deadly virus on Saturday and Monday.

The network has used this sort of reckless fearmongering as a core part of its brand since it launched in the 1990s. For decades, Fox’s hosts have sought to stampede their audience toward Republican politicians by making them fearful for their lives. But with one of their viewers ensconced in the Oval Office and often taking his cues from the network, the situation has gotten even more dangerous.