MILWAUKEE (CBS 58) -- As COVID-19 cases fall and masks come off, health officials warn that influenza cases are rising.

While flu activity has been increasing in most places across the country, the highest levels have been recorded in the central and southern states.

The number of reported flu-related hospital admissions has also increased each week for the past seven weeks.

An infectious disease expert says the rolling back of COVID-19 mitigation measures played a role in increased flu activity.

The measures include masking, limiting gatherings and moving things outside.