Here’s something you don’t hear a journalist say very often: I blew it. I was wrong.

I dismissed out of hand the suggestion by anti-immigration activists and right-wing pundits that among the worries associated with the “border kids”—the estimated 52,000 children and teenagers who have crossed the U.S.-Mexico border in the last year or so—was that they carried communicable diseases.

“How original” was probably my first thought. Immigrants and fears about disease go together like beans and rice.

Pick up a history book. In the 18th century, German immigrants coming to Pennsylvania boarded ships plagued with typhus, dysentery, smallpox, and scurvy. By the dawn of the 19th century, Irish immigrants en route to America had to contend with scarlet fever, measles, smallpox, diphtheria, typhoid fever and tuberculosis.

Issues of public health weighed heavily on the minds of the nativists of the day, who started the Know-Nothing Party in part because they feared immigrants bringing diseases. Catholics, Jews, Italians, and Greeks were thought to be particularly susceptible.

More recently—during a May 2007 interview on CBS’ 60 Minutes—CBS reporter Lesley Stahl skewered then-CNN anchor Lou Dobbs over a questionable statistic on his program regarding immigrants and leprosy. Stahl pointed to a 2005 report on Lou Dobbs Tonight that alleged that 7,000 new cases of leprosy had been discovered in the past three years and insinuated that this was due in large part to immigration.

There was only one problem: The numbers were bogus, according to the U.S. Department of Health and Human Services. The real figure was 7,000 cases of leprosy in the previous 30 years, not the last 3 years.

So, as you can see, I’d been down this “immigrants bring disease” road before, and I’d always found it to be a dead-end street paved by fear, intolerance, and prejudice.

But, in the case of the border kids, it turns out that those worries about diseases were not so far-fetched after all. And so I was wrong to dismiss them so quickly.

The border kids have been coming, in much smaller numbers, since at least 2011. Yet, the country didn’t start paying attention until June 2. That’s when the daily tally reached about 1,000 children per day, and President Obama declared the situation on the border a “humanitarian crisis.”

In the month since then, as the daily figure has climbed to as much as 1,500 kids per day, Americans have gone through the three stages of dealing with chaos: figuring out what is happening, determining who or what is to blame, and looking for solutions.

On their own, some Americans added a fourth stage: stoking fears. When the Obama administration began approaching various local communities around the country and requesting that they house some of these children in local facilities, townspeople spoke up. As one person in Escondido, California, vaguely put it, Americans along the border were worried about “an uncertain element” entering their midst.

But some of the fears being expressed were more specific. Those were the ones that involved communicable diseases—leprosy, tuberculosis, whooping cough, and the other usual suspects you often hear a lot about when you write about immigration. We’re talking about the kind of sicknesses that those of us who live in the United States usually have the luxury of not having to think about—until the Third World crashes the back gate.

The worry was that these border kids from Central America were either bringing in diseases, or contracting diseases while locked in unsanitary and overcrowded holding cells, and then spreading them to other children and incarcerated youth. At least those viruses could be somewhat contained.

The real worry was those children who had—by mid-June—already been relocated around the country, to unsuspecting communities as far away as California and Pennsylvania? What then? Before we knew it, we could be dealing with a national health emergency.

Now, sure enough, that once inconceivable nightmare scenario that we were all afraid to ponder could be one step closer to coming true. The culprit: H1N1, more commonly known as “swine flu.”

The U.S. Department of Health and Human Services recently that an unaccompanied minor from Central America has the H1N1 flu. The minor, who entered the country in the last few months, had recently been—along with 1,000 other border kids—relocated to Lackland Air Force base in San Antonio.

Meanwhile, a source close to the situation on the border told me on June 21 that there was a confirmed case of a child having the H1N1 virus. He spoke on condition of anonymity so he could relay the information candidly, given the sensitivity of the subject matter and the possibility of sparking a public panic.

According to Action 4 News, a local television station in the Rio Grande Valley, two more immigrant youths have been quarantined after they had “flu-like symptoms” at a Brownsville Border Patrol station. It has not yet been confirmed that the children have the H1N1 virus, only that they have flu-like symptoms. A Border Patrol spokesman told the news station that an estimated 120 people are also being isolated at the Brownsville Border Patrol station because they’ve been exposed.

Keep in mind that, at this point, authorities had already begun moving children to shelters around the country—some of whom might have been infected.

But it’s also important to remember that experiencing “flu-like symptoms” is extraordinarily common, and not necessarily indicative of swine flu, a harder to treat form of the virus.

You remember swine flu. The respiratory disease first made headlines in April 2009, when an epidemic was discovered in the Mexican state of Veracruz. For months, there were cross-border concerns in the United States about traveling to Mexico, and about Mexicans traveling here. Eventually, the cases tapered off. And the panic died down. Life went back to normal.

Now H1N1 may be back. It has been delivered into our air supply by unsuspecting pint-sized carriers who have endured a lot of pain, sacrifice and suffering to get here and whose fate is still unclear.

Don’t look to President Obama for clarity on immigration. His policies are somewhere between a mixture and a mess. He has said that the border kids should go home, and has asked Congress for an additional $2 billion in funding to speed up deportations in order to make that happen.

But he also said that he plans, by the end of the summer, to exercise his executive power to ease up on another set of deportations—those of illegal immigrants who have been living in the United States for a while, and who have put down roots here.

But with an estimated 120,000 kids on the way in the next year, HHS needs to be prepared with stockpiles of vaccines for swine flu and other contagious diseases. Likewise, we must redouble our efforts to screen those streaming across the border so infected migrants are properly isolated and treated.

The border kids have been through enough. They don’t deserve to fight this virus alone as well.