Shigellosis, 2017

In 2017, 86 culture-confirmed cases of shigellosis (1.6 per 100,000 population) were reported. This represents an
85% decrease from the 556 cases reported in 2016, and is 54% less than the median annual number of cases reported during 2007-2016 (median, 185.5 per year; range, 66 to 556). S. sonnei accounted for 48 (56%) cases, S. flexneri for 36 (42%) cases, and S. dysenteriae for 1 (1%) case. The species was not identified in 1 (1%) case. Cases ranged in age from 5 months to 84 years (median, 36.5 years). Twenty percent of cases were ≤5 years of age; 65% of cases were 18 years of age or older. Fifty-eight percent of cases were male. Twenty (23%) cases were hospitalized. No cases died.

Thirty-eight percent of cases reported either non-white race (24 of 80 cases) or Hispanic ethnicity (12 of 79 cases). Of the 78 cases for which travel information was available, 23 (29%) travelled internationally (11 of 44 [25%] S. sonnei, and 12 of 33 [36%] S. flexneri). Seventy-nine percent of cases resided in the metropolitan area, including 33% in Hennepin County and 22% in Ramsey County.

Two (2%) cases were part of two Shigella outbreaks (one outbreak was identified in 2016). Both outbreaks were due to person-to-person transmission of S. sonnei in child care facilities.

In 2017, 90 patients were positive for Shigella by a culture-independent diagnostic test conducted in a clinical laboratory. Thirty-one (38%) of the 82 specimens that were received at MDH were subsequently culture-confirmed and therefore met the surveillance case definition for inclusion in MDH case count totals.

In 2017, 43 of the 84 Shigella isolates received at MDH were tested for antimicrobial resistance. Of the 43 isolates, 81% (35 isolates) were resistant to trimethoprim- sulfamethoxazole, 46% (20 isolates) were resistant to ampicillin, and 23% (10) had decreased susceptibility to azithromycin (DSA). All of the DSA isolates were collected from adult males. Among the 7 cases with available information, 4 (57%) reported sexual contact with a male during the week before illness onset.

• For up to date information see>> Shigellosis (Shigella)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2017