The food safety office of the WHO on Thursday announced that the bacterium responsible for the E. coli outbreak in Europe is a strain never seen before in humans and could mean “the infection could prove unusually difficult to bring under control,” Nature News reports (Turner, 6/2).

At least 16 people have died and 1,624 cases have been reported, according to the WHO, making it “the deadliest outbreak of the bacteria on record as a rare strain is causing kidney failure in unprecedented numbers, U.S. health officials said,” Bloomberg reports (Randall/Larkin, 6/3).

“According to WHO, of more than 1,600 people sickened by this E. coli strain, 499 developed a rare and potentially fatal kidney-failure complication known as hemolytic uremic syndrome – a complication that can shut down the kidneys and normally occurs in only a small percentage of people sickened during an E. coli outbreak. It is also unusual in that most of those affected are young adults – and mostly women. E. coli infections normally hit young children and the elderly hardest,” the Wall Street Journal writes (Martin/Stevens/Miller, 6/3).

The origins of the outbreak remain unknown, and “[t]en countries have now reported cases, but virtually all of them have been traced to northern Germany, where the outbreak began several weeks ago,” according to the New York Times (Cowell/Kanter, 6/2).