Shigellosis, 2014: DCN - Minnesota Dept. of Health

Shigellosis, 2014

During 2014, 93 culture-confirmed cases of shigellosis (1.7 per 100,000 population) were reported. This represents a 31% decrease from the 134 cases reported in 2013, and is 19% lower than the annual number of cases reported during 2004-2013 (median, 115 per year; range, 66 to 391). S. sonnei accounted for 62 (67%) cases, S. flexneri for 27 (29%) cases, and S. boydii for 1 (1%) case. The species was not identified in 3 (3%) cases. There were no S. dysenteriae infections reported in 2014. Cases ranged in age from 10 months to 87 years (median, 37 years). Eight percent of cases were ≤5 years of age; 83% of cases were over 18 years of age. Sixty-two percent of cases were male. Twenty (22%) cases were hospitalized. No cases died. Twenty percent of cases reported either non-White race (13 of 86 cases) or Hispanic ethnicity (5 of 84 cases). Of the 80 cases for which travel information was available, 23 (29%) travelled internationally (17 of 56 [30%] S. sonnei, 5 of 20 [25%] S. flexneri, and 1 of 3 [33%] unknown Shigella species). Seventy-six percent of cases resided in the metropolitan area, including 41% in Hennepin County and 16% in Ramsey County.

Three (3%) cases were part of two Shigella outbreaks identified in 2014 (median, 1.5 cases per outbreak; range 1 to 2). One person-to-person outbreak in a childcare center was caused by S. sonnei. One clinical laboratory-associated outbreak of S. flexneri infections was detected in Minneapolis.

In 2014, 78 of the 80 Shigella isolates received at MDH were tested for antimicrobial resistance. Of the 78 isolates, 68% (53 isolates) were resistant to trimethoprim-sulfamethoxazole, 49% (38 isolates) were resistant to ampicillin, and 26% (20 isolates) had decreased susceptibility to azithromycin (DSA). All of the DSA isolates were collected from adult cases, 18 (90%) were men. Eight of the 9 cases with available information reported male-to-male sexual contact during the week before illness onset.

Updated Friday, September 16, 2016 at 12:10PM