The U.S. Centers for Disease Control and Prevention issued an outbreak investigation announcement on Tuesday. The agency has yet to determine the source of infection, but here’s what we know about it so far:

Its state-by-state reach

New Jersey has the largest share of people infected, with six cases reported in the state. An additional four have been reported in Idaho, and two cases each in Connecticut and Pennsylvania. So far, single cases have been reported in Missouri, Ohio, and Washington.

Who’s infected

Six people have been hospitalized, with one developing hemolytic uremic syndrome, a kidney condition. No deaths have been reported to date. Those infected began showing symptoms between March 22 and March 31. They range in age from 12 to 84 and the majority are female.

E. coli symptoms

Symptoms of an E. coli infection can include severe stomach cramps, diarrhea, nausea, and vomiting, with most people recovering after five to seven days. However, the CDC warns that symptoms typically don’t show until two to eight days after consuming the bacteria.

How E. coli spreads

E. coli is incredibly contagious, spreading easily via an infected person, the consumption of contaminated food or water, or contact with contaminated surfaces. To prevent infection, the CDC recommends washing your hands frequently, cooking meat thoroughly, washing fruits and vegetables, avoiding unpasteurized dairy and juices, and avoiding preparing meals for others when sick.