"Still Infected" - SEP 12.1

Hi,

I have problem with "Still infected" in SEP 12.1. I kow that it can't be clear manually like in version 11. 

Virus was detected when users connect flash memory to USB port. Now flash memory is not connected and Client can't scan this for check if it is infected.

Please let me know if it is possible to clean "still infected" count if Can I block USB port in SEPM policy.

Best Regards.

Damian.