Shigellosis, 2013

During 2013, 134 culture-confirmed cases of Shigella infection (2.5 per 100,000 population) were reported. This represents a 66% decrease from the 391 cases reported in 2012, but is 35% higher than the annual number of cases reported during 2003-2012 (median, 99.5 per year; range, 66 to 391 [Figure 3]). S. sonnei accounted for 86 (64%) cases, S. flexneri for 42 (31%) cases, and S. boydii for 3 (2%) cases. The species was not identified in 3 (2%) cases. There were no S. dysenteriae infections reported in 2013. Cases ranged in age from 1 month to 94 years (median, 24.5 years). Twenty-six percent of cases were ≤5 years of age. Thirty-four (25%) cases were hospitalized. No cases died. Sixty percent of cases reported either non-White race (65 of 122 cases) or Hispanic ethnicity (24 of 116 cases). Of the 110 cases for which travel information was available, 17 (16%) travelled internationally (7 of 72 [10%] S. sonnei, 8 of 33 [24%] S. flexneri, and 2 of 3 [67%] S. boydii). Seventy-one percent of cases resided in the metropolitan area, including 51% in Hennepin County and 12% in Ramsey County.

Seventeen (13%) cases were part of four Shigella outbreaks identified in 2013 (median, 4.5 cases per outbreak; range 2 to 6). Three person-to-person outbreaks were caused by S. sonnei: one in a childcare setting, one at a woman’s shelter, and one associated with a private party. One community outbreak in Minneapolis of S. flexneri infections was detected among men who have sex with men.

Approximately 25% of Shigella isolates received at MDH are tested for antimicrobial resistance. Thirty-seven isolates were tested in 2013; 70% (26 isolates) were resistant to trimethoprimsulfamethoxazole and 22% (8 isolates) were resistant to ampicillin.

• For up to date information see>> Shigellosis (Shigella)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2013