By NewsDesk  @bactiman63

San Diego County health officials reported three new shigella cases associated with an ongoing outbreak, bringing the total to 18 confirmed and three probable cases among individuals experiencing homelessness.

Image/CDC

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.

The cases are all among individuals experiencing homelessness who resided at multiple locations in central San Diego. No source of the outbreak has currently been identified.

Clinical manifestations of shigellosis range from watery or loose stools with minimal symptoms to more severe illness including high fever, abdominal cramps or tenderness, tenesmus, and mucoid stools with or without blood. Symptoms usually resolve in five to seven days but sometimes last for four or more weeks. Asymptomatic infection is possible.

Shigella bacteria are present in the stools of infected people while they have diarrhea, and for up to four weeks after symptoms resolve. The primary mode of transmission is fecal-oral, although transmission can also occur via contact with a contaminated fomite, ingesting contaminated food or water, or sexual contact. The incubation period is one to seven days, but is usually less than four days.

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Shigellosis is usually self-limited and treatment with antibiotics is not generally recommended in otherwise healthy adults with mild illness. However, antibiotics may be prescribed when warranted by the severity of the illness, underlying health conditions, or patient’s occupation.

Those at increased risk include young children (especially those in daycare), people who are experiencing homelessness, travelers to locations with poor sanitation, and men who have sex with men. In 2020, a total of 240 shigellosis cases were reported in San Diego County residents while the 426 cases reported in 2019 was the highest since 1995.