Not since the Black Death has such mysterious evil visited England. Or so the British tabloids would have you believe. dither – and you die, the Daily Mirror warned last week, supporting its advice with a victim’s tale entitled, ““Eaten Alive.’’ The Sun took a more visual approach: curse of the killer bacteria, ran the headline above a full-color photo of a flayed thigh, apparently caused by the flesh-munching microbe. But nothing could top the screamer killer bug ate my face, splayed on the front page of the Daily Star.

The culprit is a virulent strain of group A streptococcus, a bacterium present in some 10 percent of otherwise healthy people. Penicillin usually knocks out the early symptoms of an infection – blisters, diarrhea and swollen glands among them. But unchecked, the disease can progress quickly in people susceptible to infection, producing toxins and enzymes that ““liquefy’’ fat and muscle tissue, and cause gaping wounds, known as necrotising fasciitis. In extreme instances, the infection may require amputation. So far this year, there have been 15 reported incidents of toxic strep throughout Britain; 11 people have died. Four cases showed up in Gloucestershire, a county 80 miles west of London; three were fatal.

But, in fact, the only epidemic may be journalistic hysteria. ““The trouble is, the press can’t resist the idea of bugs from outer space that eat your flesh,’’ says a spokeswoman from the Public Health Laboratory Service. ““There is nothing out of the ordinary at all in what’s happened,’’ says Aberdeen University professor Thomas Pennington, an expert in streptococcal infections. ““The risk is about the same as being struck by lightning.’’ Yeah, right. Just try telling that to the first people in Dover who feel the beginnings of a scratchy throat. They’re sure to blame it all on the French, thanks to the bloody Chunnel, which doesn’t open to public traffic until the fall.