"Crack users often use and share pipes made of various makeshift materials, including broken glass pipes, metal tubing, aluminum cans, car antennas, or glass ginseng bottles, all of which can cause cuts, sores, burns, and blisters in and around the user’s mouth (Faruque et al., 1996; Porter & Bonilla, 1993; Porter, Bonilla, & Drucker, 1997; Shannon, Kerr et al., 2008). A number of recent studies point to nonIDU equipment sharing as possible routes of infectious disease transmission (Fischer, Powis, Firestone-Cruz, Rudzinski, & Rehm, 2008; Macias et al., 2008; McMahon & Tortu, 2003; Roy et al., 2001; Shannon, Rusch et al. 2008: Tortu, Neaigus, McMahon, & Hagen, 2001). In a study of drug users with no history of drug injection, Tortu et al. (2004) found noninjection drug use equipment sharing to be a risk factor for HCV infection, suggesting that HCV transmission may occur through noninjection routes such as oral and intranasal drug use methods. This is particularly concerning given that HCV is almost 30 times more infective that HIV through blood contact (Sulkowski & Thomas, 2003)."
Ivsins, A., Roth, E., Benoit, C., & Fischer, B. (2013). Crack Pipe Sharing in Context: How Sociostructural Factors Shape Risk Practices among Noninjection Drug Users. Contemporary Drug Problems, 40(4), 481–503. doi.org/10.1177/009145091304000403