The County of San Diego has announced three new shigella cases associated with an ongoing outbreak, bringing the total to 18 confirmed and three probable cases among individuals experiencing homelessness.

The continuing investigation shows onset of illness dates between Aug. 16 and Oct. 15, with the three new cases occurring between Sept. 20 and Oct. 15. The 21 cases in this outbreak represent 7.6% percent of the 275 total cases reported to date in San Diego County.