An unusually toxic version of the “Montezuma’s revenge” bacteria known as enterohemorrhagic E. coli, or EHEC,  is sweeping Europe this week and is now thought to be responsible for at least 17 deaths and over 1,500 cases of severe illness known as “hemolytic uremic syndrome.”  The World Health Organization (WHO) said cases of the E. coli illness have been reported in nine European countries: Austria, Denmark, Germany, the Netherlands, Norway, Spain, Sweden, Switzerland and the U.K. All but two cases are either people in Germany, or people who had recently traveled to northern Germany, the organization said.  The source of the food borne bacteria, generally found on vegetables, has thus far evaded health officials. Scientists are working hard to find the source of the contaminated vegetables.

Benign strains of the E. coli inhabit the human intestinal tract, while other strains are responsible for much of the diarrhea experienced by travelers to underdeveloped countries with poor water sanitation.  But EHEC, causes more severe symptoms, ranging from bloody diarrhea to the rare hemolytic uremic syndrome (HUS), in which E. coli infection attacks the kidneys, sometimes causing seizures, strokes, comas and death.

“The idea of an outbreak of over 300 hemolytic uremic syndrome cases is absolutely extraordinary,” said Dr. Robert Tauxe, deputy director of foodborne, waterborne and environmental diseases at the U.S. Centers for Disease Control.  “There has not been such an outbreak before that we know of in the history of public health,” Tauxe said, adding that the German strain of E. coli has not been seen in the United States.

Anyone traveling to Europe should be aware of the situation and avoid the consumption of raw vegetables until the situation is resolved.

If you want to track the situation, The Guardian has created an interactive map to track the E. coli spread across Europe.