SAN FRANCISCO (CBS SF) — San Franciscans this month have experienced a significant increase in the number of cases of shigellosis, an intestinal bacterial disease, city Department of Public Health officials said on Friday.

There had been 65 cases involving shigella as of Tuesday — far higher than the five to 10 cases the city typically has per month, public health officials said.

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Shigella is a fast-spreading bacteria that usually causes diarrhea. Among the cases this month, about 40 percent have been in people who are known to be homeless, according to the department.

“We are particularly concerned about our homeless residents, who are more vulnerable to disease than people with stable housing,” Dr. Tomas Aragon, the city’s health officer, said in a statement.

“People who are in crowded conditions and without access to running water and sanitation facilities are more susceptible to contracting and spreading shigella,” Aragon said.

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City officials, including the San Francisco Homeless Outreach Team, are interviewing homeless people to look for symptoms of shigellosis, handing out fliers alerting them to the outbreak and giving instructions on sanitation and hand hygiene.

More information about the outbreak can be found online at or

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