St. Louis city health officials on Wednesday reported a sharp increase in cases of a highly contagious intestinal bacteria that is typically spread by children.  There have been 67 cases of shigellosis from July 1 through Monday, compared to nine cases for all of 2008, according to the St. Louis City Department of Health.

Health officials said four day care centers and one school clustered in south St. Louis city reported illnesses. Officials did not offer other specifics except to say that children ages 4 and younger are most commonly infected.

Shigellosis infection is marked by fever, stomach cramps and diarrhea that can be bloody.  Most infections resolve without treatment within a week. Some antibiotics may be effective in treating more severe cases, although health officials warned that specimens from the St. Louis cases were shown in labs to be resistant to two antibiotics, trimethoprim-sulfamethoxazole and ampicillin.