Xenophobic commentators are doing their hysterical best to turn a public health issue into immigrant bashing.

This week, watchdog group Media Matters reported on how some conservative pundits are blaming Mexican immigrants for supposedly spreading the so-called swine flu across the border. This, despite the fact that the U.S. Centers for Disease Control and Prevention has indicated that residents who traveled to Mexico are a factor in the some of the cases here.

But as we learn more about this strain of flu and its spread, what the public needs is reliable information, not hostile rhetoric. Instead, immigrant bashers have taken to what they always do—fan hate.

At the Boston radio station WTKK, Jay Severin is using the flu to attack Mexicans and immigrants. For Severin, Mexicans are “criminaliens” and primitives who export venereal diseases to the United States. The shock jock referred to the strain of flu as “swine-aka-Janet Napolitano flu.”

That’s not the end of Severin’s anti-immigrant rants. Immigrants are leeches and their children, he warns, don’t speak English, will retard schools, add to crime and spread disease. Amid all of this, Severin has the audacity to state, “I don’t mean to hype the story.”

This tactic is not new. Anti immigrant campaigns in the 19th century painted Irish and Chinese immigrants as dirty. Decades later, xenophobes would describe immigrants from Italy and Eastern Europe as inferior. And in recent years, EL DIARIO/LA PRENSA has reported on other shock jocks, like the Jersey Guys, calling immigrants rats and roaches and Lou Dobbs irresponsibly and inaccurately associating leprosy with immigrants.