Shigellosis 
Annual Summary of Reportable Diseases

• 28% of cases with travel information available traveled internationally before onset of illness.
• 86% of cases in 2023 were in adults.
• There were no outbreaks of shigellosis identified in 2023. 

In 2023, 271 Shigella cases were reported. Of those, 84 were culture-confirmed (1.5 per 100,000 population). The remaining 187 were only tested by a culture-independent diagnostic test (CIDT) and were not subsequently confirmed. The 84 culture-confirmed Shigella cases are similar to the 86 cases reported in 2022, but 31% less than the median annual number of cases reported from 2013 to 2022 (median, 121 per year; range, 79 to 554). S. flexneri accounted for 50 (60%) cases, S. sonnei for 31 (37%) cases, S. boydii for one (1%) case, and S. dysenteriae for one (1%) case. The species was not identified for one (1%) case. Culture-confirmed cases ranged in age from 1 to 91 years (median, 36 years). Seven percent of cases were les than 5 years of age; 86% of cases were 18 years of age or older. Sixty-five percent of cases were male. Twenty-five (30%) cases were hospitalized. No cases died.

In 2023, of the 271 reported cases, 269 patients were positive for Shigella by a CIDT conducted in a clinical laboratory. Of the 257 corresponding specimens that were received at MDH, 81 (32%) were subsequently culture-confirmed. The remaining 176 cases only had specimens that were positive by a CIDT conducted at a clinical laboratory and were not subsequently culture-confirmed. The median age of the CIDT-positive only cases was 34 years (range, 10 months to 90 years). Twenty-five (13%) CIDT-positive only cases were hospitalized; the median hospital stay was 2 days (range, 1 to 6 days). No CIDT-positive only cases died.

Fifty-two percent of cases reported either non-white race (38 of 81 cases) or Hispanic ethnicity (16 of 81 cases). Of the 58 cases for whom travel information was available, 16 (28%) travelled internationally (8 of 21 [38%] S. sonnei and 7 of 35 [20%] S. flexneri). Eighty percent of cases resided in the Twin Cities metropolitan area, including 50% in Hennepin County and 15% in Ramsey County.

There were no outbreaks of shigellosis identified in 2023. 

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Shigellosis is an infection caused by the bacteria Shigella and can spread easily from person to person. In 2022, 206 Shigella cases were reported. Of those, 86 were culture-confirmed (1.5 per 100,000 population). The remaining 120 were only tested by a culture-independent diagnostic test (CIDT) and not subsequently confirmed. The 86 culture-confirmed Shigella cases represent a 21% decrease from the 109 cases reported in 2021, and is 39% less than the median annual number of cases reported from 2012 to 2020 (median, 140 per year; range, 79 to 554). S. flexneri accounted for 53 (62%) cases, S. sonnei for 28 (33%) cases, S. boydii for two (2%) cases, and S. dysenteriae for two (2%) cases. The species was not identified for one (1%) case. Culture-confirmed cases ranged in age from one to 78 years (median, 35 years). Twelve percent of cases were ≤5 years of age; 74% of cases were 18 years of age or older. Seventy percent of cases were male. Eighteen (21%) cases were hospitalized. No cases died

In 2022, of the 206 reported cases, 201 patients were positive for Shigella by a CIDT conducted in a clinical laboratory. Of the 195 corresponding specimens that were received at MDH, 81 (42%) were subsequently culture-confirmed. The remaining 114 cases only had specimens that were positive by a CIDT conducted at a clinical laboratory and were not subsequently culture-confirmed. The median age of the CIDT-positive only cases was 32 years (range, one to 90 years). Twelve (11%) CIDT-positive only cases were hospitalized; the median hospital stay was three days (range, 2 to 15 days). No CIDT-positive only cases died

Forty-five percent of cases reported either non-white race (36 of 86 cases) or Hispanic ethnicity (6 of 86 cases). Of the 65 cases for which travel information was available, 22 (34%) travelled internationally (15 of 23 [65%] S. sonnei and 6 of 38 [16%] S. flexneri). Eighty-three percent of cases resided in the Twin Cities metropolitan area, including 52% in Hennepin County and 8% in Ramsey County.

There were no outbreaks of shigellosis reported in 2022.

• For up to date information see>> Shigellosis (Shigella)

In 2021, 220 Shigella cases were reported. Of those, 109 were culture-confirmed (1.9 per 100,000 population). The remaining 111 were only tested by a culture-independent diagnostic test (CIDT) and not subsequently confirmed. The 220 culture-confirmed Shigella cases represents a 38% increase from the 79 cases reported in 2020, and is 22% less than the median annual number of cases reported from 2011 to 2020 (median, 140 per year; range, 79 to 556). S. flexneri accounted for 76 (70%) cases, S. sonnei for 28 (26%) cases, S. boydii for 2 (2%) cases, and S. dysenteriae for 1 (1%) case. The species was not identified for 2 (2%) cases. Culture-confirmed cases ranged in age from 1 to 89 years (median, 32 years). Nine percent of cases were ≤5 years of age; 85% of cases were 18 years of age or older. Seventy-five percent of cases were male. Twenty-three (21%) cases were hospitalized. No cases died.

In 2021, of the 220 reported cases, 217 patients were positive for Shigella by a CIDT conducted in a clinical laboratory. Of the 208 corresponding specimens that were received at MDH, 104 (50%) were subsequently culture-confirmed. The remaining 111 cases only had specimens that were positive by a CIDT conducted at a clinical laboratory and were not subsequently culture-confirmed. The median age of the CIDT-positive only cases was 32 years (range, 1 to 89 years). Thirteen (12%) CIDT-positive only cases were hospitalized; the median hospital stay was 2 days (range, 1 to 7 days). One CIDT-positive only case died.

Thirty-eight percent of cases reported either non-white race (30 of 100 cases) or Hispanic ethnicity (16 of 100 cases). Of the 93 cases for which travel information was available, 21 (23%) travelled internationally (8 of 25 [32%] S. sonnei and 12 of 65 [18%] S. flexneri). Eighty-four percent of cases resided in the Twin Cities metropolitan area, including 61% in Hennepin County and 17% in Ramsey County.

There was one outbreak of shigellosis associated with a restaurant.

In 2021, 35 of the 103 Shigella isolates received at MDH were tested for antimicrobial resistance. Of the 35 isolates, 74% (26 isolates) were resistant to ampicillin, 74% (26 isolates) were resistant to trimethoprim-sulfamethoxazole, and 46% (16 isolates) had decreased susceptibility to azithromycin (DSA). All but one of the 16 of the DSA isolates were collected from adult males; the remaining isolate was collected from an adult female with no history of international travel. Among the 10 adult male cases with DSA infection and available information, 7 (70%) reported sexual contact with a male during the week before illness onset.

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In 2020, 79 culture-confirmed cases of shigellosis (1.4 per 100,000 population) were reported. This represents a 52% decrease from the 165 cases reported in 2019, and is 44% less than the median annual number of cases reported during 2010-2019 (median, 140 per year; range, 66 to 556) (Figure 2). S. sonnei accounted for 38 (48%) cases, and S. flexneri for 38 (48%) cases. The species was not identified for 3 (4%) cases. Cases ranged in age from 1 to 89 years (median, 39 years). Eleven percent of cases were ≤5 years of age; 82% of cases were 18 years of age or older. Eighty-one percent of cases were male. Seventeen (22%) cases were hospitalized. No cases died.

Thirty-five percent of cases reported either non-white race (22 of 76 cases) or Hispanic ethnicity (8 of 76 cases). Of the 59 cases for which travel information was available, 12 (20%) travelled internationally (8 of 31 [26%] S. sonnei, and 4 of 26 [15%] S. flexneri). Seventy-one percent of cases resided in the metropolitan area, including 40% in Hennepin County and 13% in Ramsey County.

No outbreaks of shigellosis were identified.

In 2020, 133 patients were positive for Shigella by a culture-independent diagnostic test conducted in a clinical laboratory. Of the 127 specimens that were received at MDH, 70 (55%) were subsequently culture-confirmed and therefore met the surveillance case definition for inclusion in MDH case count totals.

In 2020, 25 of the 70 Shigella isolates received at MDH were tested for antimicrobial resistance. Of the 25 isolates, 76% (19 isolates) were resistant to ampicillin, 68% (17 isolates) were resistant to trimethoprim-sulfamethoxazole, and 44% (11 isolates) had decreased susceptibility to azithromycin (DSA). All 11 of the DSA isolates were collected from adult males. Among the 7 adult male cases with DSA infection and available information, 6 (86%) reported sexual contact with a male during the week before illness onset.

• For up to date information see>> Shigellosis (Shigella)

In 2019, 165 culture-confirmed cases of shigellosis (2.9 per 100,000 population) were reported. This represents a 13% increase from the 146 cases reported in 2018, and is 45% more than the median annual number of cases reported during 2009-2018 (median, 113.5 per year; range, 66 to 556). S. sonnei accounted for 88 (53%) cases, S. flexneri for 72 (44%) cases, and S. boydii for 2 (1%) cases. The species was not identified for 3 (2%) cases. Cases ranged in age from 4 months to 74 years (median, 37 years). Fourteen percent of cases were ≤5 years of age; 81% of cases were 18 years of age or older. Seventy-eight percent of cases were male. Forty-one (25%) cases were hospitalized. One case died.

Thirty-three percent of cases reported either non-white race (43 of 159 cases) or Hispanic ethnicity (19 of 158 cases). Of the 148 cases for which travel information was available, 41 (27%) travelled internationally (25 of 80 [31%] S. sonnei, and 12 of 63 [19%] S. flexneri). Eighty-four percent of cases resided in the metropolitan area, including 59% in Hennepin County and 13% in Ramsey County.

One outbreak of shigellosis in a childcare center was identified. Additionally, an outbreak of Shigella infections among Minnesota residents who dined at a restaurant in Costa Rica was also investigated.

In 2019, 273 patients were positive for Shigella by a culture-independent diagnostic test conducted in a clinical laboratory. Of the 268 specimens that were received at MDH, 135 (50%) were subsequently culture-confirmed and therefore met the surveillance case definition for inclusion in MDH case count totals.

In 2019, 55 of the 157 Shigella isolates received at MDH were tested for antimicrobial resistance. Of the 55 isolates, 78% (43 isolates) were resistant to trimethoprimsulfamethoxazole, 73% (40 isolates) were resistant to ampicillin, and 45% (25) had decreased susceptibility to azithromycin (DSA). Twenty-four (96%) of 25 of the DSA isolates were collected from adult males. Among the 17 adult male cases with DSA infection and available information, 10 (59%) reported sexual contact with a male during the week before illness onset.

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In 2018, 146 culture-confirmed cases of shigellosis (2.6 per 100,000 population) were reported. This represents a 70% increase from the 86 cases reported in 2017, and is 29% more than the median annual number of cases reported during 2008-2017 (median, 113.5; range, 66 to 556). S. sonnei accounted for 82 (56%) cases, S. flexneri for 55 (38%) cases, and S. boydii for 1 (1%) case. Species was not identified for 8 (5%) cases. Cases ranged in age from 1 to 87 years (median, 38 years). Eight percent of cases were ≤5 years of age; 85% were 18 years of age or older. Sixty-nine percent of cases were male. Forty-five (31%) cases were hospitalized. No cases died.

Thirty-three percent of case were either non-white race (33 of 134 cases) or Hispanic ethnicity (17 of 134 cases). Of the 126 cases for which travel information was available, 39 (31%) travelled internationally (26 of 75 [35%] S. sonnei, and 10 of 44 [23%] S. flexneri) prior to onset. Eighty-three percent of cases resided in the metropolitan area, including 49% in Hennepin County and 15% in Ramsey County.

No outbreaks of shigellosis were reported in 2018.

In 2018, 224 patients were positive for Shigella by a culture-independent diagnostic test conducted in a clinical laboratory. Of the 215 specimens that were received at MDH, 116 (54%) were subsequently culture-confirmed and therefore met the surveillance case definition for inclusion in case count totals.

In 2018, 57 of the 140 Shigella isolates received at MDH were tested for antimicrobial resistance. Of the 57 isolates, 86% (49 isolates) were resistant to trimethoprimsulfamethoxazole, 77% (44 isolates) were resistant to ampicillin, and 63% (36) had decreased susceptibility to azithromycin (DSA). Thirty-four (94%) of 36 of the DSA isolates were collected from adult males. Among the 27 adult male cases with DSA infection and available information, 17 (63%) reported sexual contact with a male during the week before illness onset.

• For up to date information see>> Shigellosis (Shigella)

• Archive of Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health
  Archive of past summaries (years prior to 2023 are available as PDFs).