MOUNT CLEMENS, Mich. (AP) — A sampling of sanitary sewage in one southeastern Michigan county has shown an increase in the presence of COVID-19.

Sewage samples pulled from sites across Clinton Township show the rate of actual infection is higher than numbers currently reported by state health officials, the Macomb County Public Works office said Tuesday.

Macomb County has reported more than 60,000 virus cases and 1,880 deaths since the start of the pandemic.

The state’s COVID-19 cases also have been increasing. Dr. Joneigh Khaldun, Michigan’s chief medical executive, has said Michigan’s case rate spiked 77% over the past four weeks to 172.9 cases per million people.