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Harmful Algal Bloom Statistics
Human Cases
From 2014 to 2022, MDH received reports of 11 HAB-associated illnesses: 3 suspect cases and 8 probable cases. Case statuses are determined based on the CDC OHHABS Case Definitions. The median number of cases annually was 1 (range, 0 to 4). The median age of cases was 10 years (range, 2 to 38 years). All cases were exposed to HABs during May through August, with 64% of cases exposed in July.
Animal Cases
From 2014 to 2022, MDH received reports of 15 animal HAB-associated illnesses: 6 suspect cases, 8 probable cases, and 1 confirmed case. Case statuses are determined based on the CDC OHHABS Case Definitions. The median number of animal cases annually was 1 (range, 0 to 5). All animal HAB-associated illness cases were dogs. All animal cases were exposed to HABs during March through September. Eleven (73%) cases died as a result of their illness.
Charts, Graphs, and Maps
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HAB-Associated Illness Cases in Minnesota by Year, 2014-2022 (PDF) Bar graph of confirmed, suspected, and probable HAB-associated illness cases in Minnesota per year by illness type. |
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Human HAB-Associated Illness Cases in Minnesota by County of Exposure, 2014-2022 (PDF) Map of the total number of confirmed, suspected, and probable human HAB-associated illness cases in Minnesota from 2014 to 2022 by county of exposure. |
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Animal HAB-Associated Illness Cases in Minnesota by County of Exposure, 2014-2022 (PDF) Map of the total number of animal HAB-associated illness cases in Minnesota from 2014 to 2022 by county of exposure. |
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Animal and Human HAB-Associated Illness Cases in Minnesota by County of Exposure, 2014-2022 (PDF) Map of the total number of animal and human HAB-associated illness cases in Minnesota from 2014 to 2022 by county of exposure. |
| HAB-Associated Illness Cases in Minnesota by Year, 2014-2022 | ||||||
|---|---|---|---|---|---|---|
| Year | Human Cases | Animal Cases | ||||
| Probable | Suspected | Confirmed | Probable | Suspected | Confirmed | |
| 2014 | 0 | 0 | 0 | 3 | 2 | 0 |
| 2015 | 4 | 0 | 0 | 0 | 1 | 1 |
| 2016 | 0 | 2 | 0 | 0 | 0 | 0 |
| 2017 | 0 | 0 | 0 | 1 | 1 | 0 |
| 2018 | 0 | 0 | 0 | 0 | 0 | 0 |
| 2019 | 2 | 1 | 0 | 1 | 2 | 0 |
| 2020 | 0 | 0 | 0 | 1 | 0 | 0 |
| 2021 | 1 | 0 | 0 | 1 | 0 | 0 |
| 2022 | 1 | 0 | 0 | 1 | 0 | 0 |
| Animal and Human HAB-Associated Illness Cases in Minnesota by County of Exposure, 2014-2022 | |||
|---|---|---|---|
| County of Exposure | Human Cases | Animal Cases | Total Cases |
| Aitkin | 0 | 0 | 0 |
| Anoka | 1 | 0 | 1 |
| Becker | 0 | 0 | 0 |
| Beltrami | 0 | 0 | 0 |
| Benton | 0 | 0 | 0 |
| Big Stone | 0 | 0 | 0 |
| Blue Earth | 0 | 0 | 0 |
| Brown | 0 | 0 | 0 |
| Carlton | 0 | 0 | 0 |
| Carver | 0 | 0 | 0 |
| Cass | 0 | 0 | 0 |
| Chippewa | 0 | 0 | 0 |
| Chisago | 0 | 0 | 0 |
| Clay | 0 | 0 | 0 |
| Clearwater | 0 | 0 | 0 |
| Cook | 0 | 0 | 0 |
| Cottonwood | 0 | 0 | 0 |
| Crow Wing | 0 | 0 | 0 |
| Dakota | 1 | 0 | 1 |
| Dodge | 0 | 0 | 0 |
| Douglas | 1 | 2 | 3 |
| Faribault | 0 | 0 | 0 |
| Fillmore | 0 | 0 | 0 |
| Freeborn | 0 | 0 | 0 |
| Goodhue | 0 | 0 | 0 |
| Grant | 0 | 0 | 0 |
| Hennepin | 0 | 1 | 1 |
| Houston | 0 | 0 | 0 |
| Hubbard | 0 | 0 | 0 |
| Isanti | 0 | 0 | 0 |
| Itasca | 0 | 0 | 0 |
| Jackson | 0 | 0 | 0 |
| Kanabec | 0 | 0 | 0 |
| Kandiyohi | 0 | 0 | 0 |
| Kittson | 0 | 0 | 0 |
| Koochiching | 0 | 0 | 0 |
| Lac qui Parle | 0 | 0 | 0 |
| Lake | 0 | 0 | 0 |
| Lake of the Woods | 0 | 1 | 1 |
| Le Sueur | 0 | 0 | 0 |
| Lincoln | 0 | 0 | 0 |
| Lyon | 0 | 0 | 0 |
| Mahnomen | 0 | 0 | 0 |
| Marshall | 0 | 2 | 2 |
| Martin | 0 | 0 | 0 |
| McLeod | 0 | 0 | 0 |
| Meeker | 0 | 0 | 0 |
| Mille Lacs | 0 | 0 | 0 |
| Morrison | 0 | 0 | 0 |
| Mower | 0 | 0 | 0 |
| Murray | 0 | 1 | 1 |
| Nicollet | 0 | 0 | 0 |
| Nobles | 0 | 0 | 0 |
| Norman | 0 | 0 | 0 |
| Olmsted | 0 | 0 | 0 |
| Otter Tail | 1 | 0 | 1 |
| Pennington | 0 | 0 | 0 |
| Pine | 0 | 1 | 1 |
| Pipestone | 0 | 0 | 0 |
| Polk | 0 | 0 | 0 |
| Pope | 0 | 1 | 1 |
| Ramsey | 0 | 0 | 0 |
| Red Lake | 0 | 0 | 0 |
| Redwood | 0 | 0 | 0 |
| Renville | 0 | 0 | 0 |
| Rice | 0 | 0 | 0 |
| Rock | 0 | 0 | 0 |
| Roseau | 0 | 0 | 0 |
| Scott | 0 | 0 | 0 |
| Sherburne | 0 | 1 | 1 |
| Sibley | 0 | 0 | 0 |
| St. Louis | 0 | 0 | 0 |
| Stearns | 0 | 0 | 0 |
| Steele | 0 | 0 | 0 |
| Stevens | 0 | 0 | 0 |
| Swift | 0 | 0 | 0 |
| Todd | 0 | 0 | 0 |
| Traverse | 0 | 0 | 0 |
| Wabasha | 0 | 0 | 0 |
| Wadena | 0 | 0 | 0 |
| Waseca | 2 | 1 | 3 |
| Washington | 1 | 0 | 1 |
| Watonwan | 0 | 0 | 0 |
| Wilkin | 0 | 0 | 0 |
| Winona | 0 | 2 | 2 |
| Wright | 0 | 2 | 2 |
| Yellow Medicine | 0 | 0 | 0 |
| Outside of Minnesota | 4 | 0 | 4 |