Hepatitis C in patients with co-occurring mental disorders and substance use disorders: is tobacco use a possible risk factor?

This study of a dually diagnosed population in Colorado estimated the prevalence of hepatitis C to be 29.7%, or sixteen times higher than that in the general population. In attempts to determine possible risk factors, a surprisingly high correlation was found between the use of tobacco and HCV infection. This appears to be beyond the risk factor conveyed by IV drug use. Of the patients whose primary diagnoses were cocaine, opiate, amphetamine, or poly-substance dependence (drugs often used intravenously), 42% of the tobacco users were HCV positive, while only 20% of the non-tobacco using patients with similar primary diagnoses were HCV positive. The association of tobacco use with HCV was found to be even more striking for females with alcohol, sedative/hypnotic, inhalant, or cannabis dependence, as none of the seventeen non-tobacco using female patients with these diagnoses were HCV positive, while fourteen of the 45 (31%) tobacco-using females with these diagnoses did test positive for HCV. Results of this study suggest that tobacco use may in some way influence the susceptibility to infection with hepatitis C virus.