Preparedness and Response Planning

While IDPH does not anticipate widespread local transmission in Illinois, it is important to plan for all phases of potential transmission. IDPH will determine its response to potential Zika virus transmission according to the chart below. This chart presents a phased approach to preparation for, management of, and response to potential local transmission and/or an outbreak of Zika virus.

Stage Phase Level Transmission Risk Category
Pre-incident 0 Pre-Season Preparedness – Travel-associated human cases possible; fall and winter weather conditions not suitable for mosquito-borne Zika virus transmission.
1 Mosquito Surveillance and Control – Spring and summer seasonal Aedes albopictus mosquito biting activity occurring. Viremic travel-associated cases occurring, possibly infecting vector mosquitoes. Vector mosquito surveillance activities being conducted if appropriate. Survey for the presence of invasive Aedes aegypti conducted.
Suspected/Confirmed Incident 2 Local Confirmed Transmission – A single, locally-acquired case, or small number of cases clustered in a single household or neighborhood.
Incident/Response 3 Widespread Local Transmission – Localized Zika virus illnesses with onsets occurring within a 1 mile radius, and within a single jurisdiction.
4 Widespread Multi-jurisdictional Transmission – Zika virus illnesses occurring in more than 1 jurisdictional area.