Hepatitis B is one of the major public health problems in the world. According to World Health Organization (WHO) data, about 2 billion people have been in contact with the hepatitis B virus (HBV), and 257 million have chronic HBV infection.

Although France is a low endemic country, with just over 280,000 people with chronic infection, hepatitis B remains a public health problem due to its morbidity and mortality.

Drug users are a population at risk by their consumption practices (injection or sniffing), but also by other high-risk behaviours, particularly sexual behaviours.

Prevention therefore involves securing consumption practices (sterile and single-use equipment) and protection of sexual intercourse, but also by vaccination (protecting more than 90%).

Since 1982, HAS has recommended to systematically vaccinate drug users. However, according to the Marmottan study published in 2003, immunization coverage among drug addicts was already insufficient in 1999 (45.3%) and decreased again in 2000 and 2001 (15.6 and 21.7%).

This decrease can be explained by the controversy around the potential link, now refuted, between vaccine against HBV and demyelination, which has stopped the mass vaccination campaign launched by the French health authorities in 1995.

A study conducted between 2009 and 2012 on injecting drug users in Alsace, estimated vaccination coverage at 28%.

The hypothesize is that despite the recommendations in a population at high risk of contamination, and a balance of benefits and risks in favor of vaccination, vaccination coverage against the hepatitis B virus remains insufficient among drug users because of poor vaccination acquaintance, and hepatitis B in general, in this population.

Principal objective of this study is to identify non-vaccination factors against hepatitis B virus among drug users consulting at the Croix-Rousse CSAPA.

Inclusion Criteria:

• Adults (age ≥ 18 years)
• Patients with an addiction with product, substituted / weaned or not
• Patients consulting at the CSAPA of the Croix-Rousse hospital

Exclusion Criteria:

• Patients with an addiction without a product
• Patients who have never snorted or injected psychoactive product
• Patients protected by the law
• Patient refusing to participate to the study

Adult patients drug users, substituted / weaned or not, consulting at the Croix-Rousse CSAPA