Shigellosis, 2012

During 2012, 391 culture-confirmed cases of Shigella infection (7.3 per 100,000 population) were reported. This represents a 349% increase from the 87 cases reported in 2011, and is higher than the annual number of cases reported during 2002-2011 (median, 99.5 per year; range, 66 to 311). S. sonnei accounted for 366 (94%) cases, S. flexneri for 20 (5%) cases, S. boydii for 2 (1%) cases and S. dysenteriae for 2 (1%) cases. Cases ranged in age from 9 months to 82 years (median, 9 years). Thirty-seven percent of cases were <5 years of age. Fifty-six (14%) cases were hospitalized, including 20 (36%) hospitalizations in children <18 years of age. One 82 year-old case died of coronary artery disease secondary to cardiomyopathy 3 days after S. sonnei was cultured from a stool specimen. Fifty-one percent of cases reported either non-White race (161 of 362 cases) or Hispanic ethnicity (48 of 350 cases). Of the 347 cases for which travel information was available, 19 (5%) travelled internationally (10 of 324 [3%] S. sonnei, 7 of 18 [39%] S. flexneri, 2 of 2 S. dysenteriae, and 0 of 2 S. boydii.) Sixty-two percent of cases resided in the metropolitan area, including 31% in Ramsey County and 20% in Hennepin County.

Ninety-one (23%) cases were part of 23 S. sonnei outbreaks identified in 2012 (median, 2 cases per outbreak; range 1 to 16). Twenty-two outbreaks were due to person-to-person transmission in daycare settings (childcare centers and family childcare homes) and one was a person-to-person outbreak at a private party.

Every tenth Shigella isolate received at MDH is tested for antimicrobial resistance. Thirty-nine isolates were tested in 2012; 67% (26 isolates) were resistant to trimethoprimsulfamethoxazole and 15% (6 isolates) were resistant to ampicillin.

Updated Thursday, May 29, 2014 at 01:24PM