At least 105 people in and around Sioux City, IA, have fallen ill with Shigella infections since October, a “significant increase” in cases, according to the Siouxland District Health Department. More than 60 percent of the victims are 10 years old or younger, a health department official told KTIV News. Shigella infection has the potential to cause severe, bloody diarrhea, fever and stomach cramps. The illness usually lasts five to seven days. The Shigella bacteria are considered highly contagious and can be passed from person to person even if an infected individual is not showing any symptoms of illness. Frequent hand-washing can help prevent the spread of infection. Siouxland health officials are trying to determine the source of the illness.