Is there a hep c or hiv risk from sniffing cocaine with a straw or bank note that is shared. There appeared to be no visible blood on it ya never know tho and the act was done on toliet paper dispenser probably not the most sanitary of conditions. Has there been any documented cases of infection and when do you recommend testing after exposure.

Theoretically yes, in practice no. 

This is another version of your continued anxiety-driven questions. You were warned earlier by Dr. Handsfield.  This is the only response you will get on this question.  You need to move on.  EWH