Netherlands National Drug Monitor - Research and Documentation ...

• In Amsterdam, about half of the approximately 2,500 methadone users are receiving
treatment at methadone centres or GGD outpatient clinics. Between 2004 and 2008,
1,140 tests were conducted in this group, with 28 testing positive for HIV. Assuming
that each patient is tested only once, this represents a HIV prevalence rate of 2.5%
in this group of more ‘seriously’ addicted heroin users.
• In Rotterdam, the pilot project ‘Active Testing’ took place in 2007 and 2008. This
showed that 2.4% of tested drug users were HIV positive (Breemer et al., 2009).
• In Heerlen, since 2003, drug users being treated at the Mondriaan addiction care
centre are voluntarily tested for drug-related infectious diseases. The (incomplete) list
of test results shows that 9% of the 197 tested individuals are HIV positive.
The third source of data on HIV is the Amsterdam Cohort Study. In this longitudinal
study, a sharp drop has been found over the past 20 years in the percentage of HIVpositive
drug users, in particular, young drug users (< 30 years old when in included in
the study).
• The incidence of new HIV diagnoses among ever injectors has dropped from 8.5 per
100 person years in 1986 to around 0 since 2000, with a slight rise in 2005, when
two injecting drug users tested HIV-positive. Up to and including 2008, no new HIV
infections were subsequently recorded (www.amsterdamcohortstudies.org).
• Of all 1,4888 participants in the drug users’ cohort study since 1985, 28% were
found to be HIV positive during the first visit or one of the subsequent visits.
• Of the 335 individuals who attended the Amsterdam GGD in 2008 to participate in
a drug user’s cohort study, 15% tested positive for HIV during a first or subsequent
visit. 5% of the 55 young drug users who were still active in the cohort study in 2008
were HIV positive, i.e., three individuals www.amsterdamcohortstudies.org).
Finally, data are available from surveys conducted by the RIVM between 1994 and
2003, among samples of injecting drug users. A total of some 3,500 injecting hard drug
users participated, in nine regions of the Netherlands (De Boer et al., 2006). The main
results have been described in earlier editions of the NDM Annual Report.
• Summarized briefly, these surveys showed considerable regional differences in HIV
infection among ever injectors, ranging from 1 percent (Groningen, Arnhem) to 26%
(Amsterdam). Besides methodological considerations, these differences can be largely
attributed to actual differences in regional rates of infection.
• In cities where repeat measurements were conducted, the percentage of HIV-positive
injecting drug users was found to be fairly stable. An exception was Heerlen, where
the number doubled from 11% in 1994 to 22% in 1999.
• In 2007 a decision was taken by the RIVM to discontinue these surveys, unless in the
future other sources – such as those described above – should disclose specific areas
of concern, justifying more in-depth study. On account of the increase registered
within a few years in the number of HIV-positive drug users in Heerlen, the Ministry
for Health has asked the RIVM to conduct a new measurement. This is likely to take
place in 2010.
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