Hepatitis is an inflammation of the liver, often caused by a viral infection. Hepatitis B (HBV) and Hepatitis C (HCV) are particularly relevant to individuals who use illegal drugs because they are primarily transmitted through blood. These viruses can lead to severe liver damage, including cirrhosis and liver cancer, if left untreated. Understanding how these bloodborne viruses spread within this population is important for prevention.
Shared Injection Equipment
The direct sharing of needles and syringes is the most common route for hepatitis B and C transmission among individuals who inject drugs. Even microscopic amounts of blood left in a syringe or on a needle after use by an infected person can contain enough viral particles to transmit the infection to the next user.
This high-risk behavior significantly increases the likelihood of infection. Hepatitis C, for instance, spreads through contact with an infected person’s blood, and injection drug use is a major factor for its transmission. Similarly, HBV easily spreads through needles and syringes tainted with infected blood, making sharing equipment for illicit drug injection a high-risk activity for hepatitis B. The lack of access to sterile supplies often leads to the repeated use of syringes, further increasing the risk of infection.
The practice of “blood flashing,” where users draw blood back into the syringe to dissolve the drug, can also contaminate the syringe with a larger volume of blood, increasing the viral load transferred. Other items directly associated with injection, such as tourniquets, can become contaminated with blood and facilitate transmission if shared. Syringe services programs (SSPs) aim to reduce these harms by providing sterile injection equipment, which has been shown to reduce the incidence of HIV and HCV.
Other Drug Preparation Materials
Beyond needles and syringes, other materials used to prepare injectable drugs also pose a significant risk for hepatitis transmission. “Cookers” or “works,” which are small containers like bottle caps or spoons used to dissolve drugs, can become contaminated with blood during the heating or drawing-up process. Cotton filters, used to strain out impurities before injection, can retain infected blood.
If these items are shared, even if a new needle is used, residual blood containing the hepatitis virus can be transferred to the next user. Research indicates that hepatitis C virus (HCV) can remain infectious on filters. Studies have shown that sharing drug cookers and filtration cotton is associated with HCV seroconversion, even among individuals who do not share syringes.
Rinse water, sometimes used to clean syringes between injections, can become contaminated with blood and transmit the virus if shared or reused. HCV can survive in bottled water, highlighting the persistence of the virus in shared water containers. These indirect routes emphasize that transmission risk extends beyond direct needle sharing to the entire drug preparation process.
Environmental and Behavioral Factors
Environmental conditions and specific behaviors among individuals who use illegal drugs contribute to hepatitis spread. Contaminated surfaces in shared drug use spaces, such as tabletops or other common areas, can harbor blood containing the virus. If an individual has open wounds or touches mucous membranes after contact with these surfaces, indirect transmission is possible. Hepatitis A, for instance, can persist on surfaces for several months after the virus leaves an infected person’s body.
Poor hygiene practices, such as not cleaning equipment thoroughly or reusing items, increase the risk of self-infection if an individual has already been exposed to the virus. Sharing personal items like razors or toothbrushes, which may come into contact with blood, also presents a transmission risk for hepatitis B and C, especially in shared living environments.
High-risk sexual behaviors, which can often co-occur with drug use, serve as another pathway for hepatitis B and C transmission. Hepatitis B can spread through sexual contact, including through blood, semen, or other body fluids. Limited access to sterile drug supplies, clean water, and comprehensive harm reduction education can exacerbate these risks, making outbreaks more challenging to control within this population.