Transmission of hepatitis C virus among people who inject drugs: viral stability and association with drug preparation equipment.

BACKGROUND Hepatitis C virus (HCV) transmission among people who inject drugs remains a challenging public health problem. We investigated the risk of HCV transmission by analyzing the direct association of HCV with filters, water to dilute drugs, and water containers. METHODS Experiments were designed to replicate practices by people who inject drugs and include routinely used injection equipment. HCV stability in water was assessed by inoculation of bottled water with HCV. Viral association with containers was investigated by filling the containers with water, inoculating the water with HCV, emptying the water, and refilling the container with fresh water. Transmission risk associated with drug preparation filters was determined after drawing virus through a filter and incubating the filter to release infectious particles. RESULTS HCV can survive for up to 3 weeks in bottled water. Water containers present a risk for HCV transmission, as infectious virions remained associated with water containers after washing. Physical properties of the water containers determined the degree of HCV contamination after containers were refilled with water. HCV was also associated with filter material, in which around 10% of the viral inoculum was detectable. CONCLUSIONS This study demonstrates the potential risk of HCV transmission among injection drug users who share water, filters, and water containers and will help to define public health interventions to reduce HCV transmission.