Netherlands National Drug Monitor - Research and Documentation ...

• The data on infection rates that emerge from these projects are not representative
of all drug users. This is not only because only drug users who are in contact with
addiction services are screened, but also because selection takes place within this
group as to who is tested or not. It is difficult to assess whether this leads to an
overestimate or underestimate of the true number of infections.
• In a longitudinal study in Amsterdam, 59% of 396 ever injecting drug users were
found to be HCV positive (Van Veen, 2009).
• Data from GGD Amsterdam show a high percentage of hepatitis C infection among
injecting drug users attending methadone dispensaries. In 2007, 57% (26 of the 46)
of patients tested were carriers of the hepatitis C virus. In 2008, the virus was found
in 65% of the 48 injecting drug users tested.
• In 2007 and 2008, the pilot project Active Testing was conducted in Rotterdam. In
this project, drug users and semi-homeless people were offered active screening for
Hepatitis C, B and HIV. The pilot results showed that 119 (28%) of the 431 individuals
tested (mostly drug users) had a Hepatitis C infection. Of the group with the highest
risk behaviour – drug users and ex-drug users who had ever injected drugs – three
quarters were Hepatitis C positive (Breemer et al., 2009).
• In Rotterdam, the majority (59%) of those infected had difficult-to-treat virus variants
(geno type 1 and 4) (Breemer et al., 2009).
• Remarkably, one seventh of those found to be infected with Hepatitis C in the Active
Testing project claimed never to have injected drugs.
• In Heerlen, approximately half the drug users receiving treatment at the Mondriaan
addiction care centre were screened for Hepatitis C. The virus was found in
58% of them (Van Veen, 2009). The percentage of (ever) injectors in this group is
unknown.
• In Injecting drug users the unfortunate combination of a dual infection with both
Hepatitis C and HIV is often encountered. Data from the HIV Monitoring Foundation
show that 94 percent of tested HIV-positive injecting drug users in active follow-up
care were also infected with hepatitis C. Infection among other HIV risk groups is less
than 10% (Gras et al.,2007).
• An acute Hepatitis C infection is a notifiable disease. Although the number of (injecting)
drug users who have a chronic Hepatitis C infection is high, acute Hepatitis C is rarely
found in drug users. Of the 48 cases of acute or recent Hepatitis C infection reported
to the RIVM in 2008, the transmission route was known in 39 cases; in only one case
(2.6%),was the route known to be injecting drug use. In both absolute and relative
terms this represents a decline compared to previous years. Hepatitis C infections are
however, increasingly encountered in men who have sex with men (MSM). Chronic
HCV infection among drug users is no longer notifiable since 2003; consequently
there is a lack of data from this source on the prevalence of this infection among
drug users.
• Injecting drug use is less often the reason for hepatitis B infections. In 2008 the RIVM)
registered 265 new cases of acute Hepatitis B infection. The cause of infection was
known in 165 of these. In no cases was the infection caused by injecting drug use.
4 Opiates
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