The Netherlands Drug Situation 2010 - Trimbos-instituut

notify the disease, the large-scale availability of serological tests and the screening programsamong blood donors). Since 1981 the incidence has decreased again, which canbe attributed to the availability of a vaccine and the decrease in sexual risk behaviour asa reaction to the aids-epidemic (Rijlaarsdam 1999). In 1995, the number of acute hepatitisB cases among people with injecting drug use peaked with 24 cases, but a sharp decreasehas taken place since then. In recent years, injecting drug use plays only a marginalrole in newly diagnosed acute and chronic hepatitis B infections. In 2009, 201 acute cases of hepatitis B infection were notified (see also ST09 part 4).In the 159 cases with known route of infection, unprotected sexual contact was foundto be still the most important risk factor. There were no notifications of acute hepatitisB in injecting drug users in 2009. In 2005 and 2008 acute hepatitis B infectionswere also not reported among injecting drug users, while the numbers reported in2006 (1 case) and 2007 (2 cases) were only very small (source: RIVM). Chronic infections with hepatitis B were reported in 1,756 cases in 2009. In 6 of the1,251 chronic infections with known route of infection injecting drug use was regardedas the vector, which is only slightly more than the 3 out of 1,108 cases withknown route of infection from 2008 (source: RIVM).Hepatitis C is a notifiable disease since April 1999. Until October 2003 both chronic andrecent HCV infections had to be reported to the Health Care Inspectorate within 24 hoursafter the diagnosis (positive test for HCV or HCV-RNA-PCR, with or without clinical symptoms).Since October 2003, this procedure only applies to (suspected) acute or recentinfections. As acute infections are often asymptomatic, an unknown rate of missed diagnosingand underreporting is possible. There is a recent decline in notified cases of acutehepatitis C among injecting drug users. In 2009, 47 cases of acute hepatitis C infection were notified. The transmission routeof 38 of these 47 cases was reported; in 3 cases (8%) injecting drug use was thelikely route of transmission (see ST09), which is only slightly more than the 1 out of39 cases with known route of transmission in 2008 (source: RIVM).Treatment data and other sourcesScreening of drug users in drug treatment on infectious diseases is no routine procedureand data are only available for a few treatment centres. There are however quite somedata available on hepatitis infections in the (former) IDUs in the database of the nationalHIV/ AIDS registration of the HIV Monitoring Foundation (SHM). In total 13,056 HIVinfectedpatients, aged 18 years or over and on combination antiretroviral therapy(cART), were tested for both HBV and HCV (Gras et al., 2009). 664 IDUs were included in the analyses, of whom 37 were not screened on HBV and/or HCV. Of the remaining 627, 51 (8%) were positive for only HIV. For comparison: inMSM, 85% of 8203 tested were only infected with HIV, and 89% of heterosexuals. Co-infection with HCV was the most prevalent in IDUs: 570 of 627 (91%) HIVpositiveIDUs were HCV-infected, of whom 63 (10% of total IDUs tested) were alsoinfected with HBV. In MSM, 7% were infected with HCV (with or without HBV); in heterosexuals4% had also an infection with HCV (with or without an HBV infection). Only 6 IDUs (1%) were infected with HBV and HIV. Multivariate analyses showed that injecting drug use was by far the largest risk factorfor hepatitis co-infection (multivariate odds ratio 86.9, 95% CI 59.0-128.0) (Gras etal., 2009).85