Due to record high case counts, the Illinois Department of Public Health has decided to centralize contact tracing.
A Rock Island County press release says all local health departments are overwhelmed and don't have enough staff to handle the high volume of calls. So, the state public health department will take over on Thursday.

Instead of getting a call from an employee of the local health department, all COVID-19 patients will receive automated telephone or text messages.
They'll come from the Illinois Department of Public Health Surge Center. The messages will include instructions and guidance about isolation and quarantine. And the calls and texts will come from this number, 1.312.777.1999.
For COVID-19 patients to get work release letters, they'll have to request them from the state through the automated Surge Center.
In addition, the Rock Island County Health Department says it, "will continue to handle congregate care and school outbreaks." ("Congregate care" includes long term care centers and group homes among other entities.)
The Iowa Public Health Department took over all contact tracing in the state early in the pandemic.