"The potential for blood-borne viral transmission via injection equipment other than syringes was reported in an earlier study of equipment collected in a Miami shooting gallery, where HIV-1 DNA was detected in rinses from cottons and cookers and in water used to clean paraphernalia and to dissolve drugs. A sterile syringe may become contaminated when the tip of the needle is inserted into a contaminated cooker or when the drug is drawn up through contaminated filtration cotton. This type of injection risk behavior appears to be quite common, and fewer injection drug users may recognize the hazard of sharing drug preparation equipment than recognize the hazard of sharing syringes. The present study suggests that HCV may be transmitted via the shared use of drug cookers and filtration cotton even without injection with a contaminated syringe."

Source

Hagan, Holly, PhD, Thiede, Hanne, DVM, MPH, Weiss, Noel S., MD, DrPH, Hopkins, Sharon G., DVM, MPH, Duchin, Jeffrey S., MD, and Alexander, E. Russell, MD, "Sharing of Drug Preparation Equipment as a Risk Factor for Hepatitis C," American Journal of Public Health, Vol. 91, No. 1, Jan. 2001, p. 43.