Case studies for existing risks in the first section include drug use in Italian professional delivery truck drivers and using look-back risk assessment for syringe reuse in Canada. The first chapter by Oraby et al. describes the occurrence of syringe reuse reported in a Canadian health care setting on approximately 1,400 patients in the province of Alberta. Multiple syringe re-use events may act as a vector to transmit both RNA and DNA viruses. This look-back study analyzed the risks for Hepatitis B (HBV), Hepatitis C (HCV) and Human Immunodeficiency Virus (HIV) using a probabilistic model with sensitivity analyses
