Surveillance reports posted weekly during flu season
Summaries of previous flu seasons in South Dakota
South Dakota reports influenza activity to the Centers for Disease Control and Prevention using the following CDC definitions.
| Influenza-like illness (ILI) | Fever >=100° F and cough or sore throat |
| No Activity | Overall clinical activity remains low and there are no lab confirmed cases |
| Sporadic Activity | Isolated cases of lab confirmed influenza in the state; Influenza-Like-Illness (ILI) activity is not increased. |
| Local Activity | Increased ILI within a single region** AND recent (within the past 3 weeks) laboratory evidence of influenza in that region. ILI activity in other regions is not increased. |
| Regional Activity | Increased ILI in ≥2 but less than half of the regions AND recent (within the past 3 weeks) lab confirmed influenza in the affected regions. |
| Widespread Activity | Increased ILI and/or institutional outbreaks (ILI or lab confirmed) in at least half of the regions AND recent (within the past 3 weeks) lab confirmed influenza in the state. |
