[HIV-positive drug users in South Limburg: number and characteristics, a capture-recapture analysis]

To estimate the number of HIV positive drug abusers (HDs) in South Limburg, the Netherlands, and to ascertain the characteristics of this group, so that special HIV healthcare can be planned.

Capture-recapture analysis.

Capture-recapture analysis was carried out and abuser characteristics were determined using three incomplete, partially overlapping registers of HDs from the regional AIDS hospital, the Regional Institute for Addiction and the Municipal Health Service Centres in South Limburg.

From the 80 HDs included, the Municipal Health Service Centres observed 59 HDs, the Institute for Addiction 45 and the hospital 44. The capture-recapture analysis gave an estimate of 110 HDs (95% CI: 91-164) in South Limburg. Assuming 1100 drug users in South Limburg of which 76% had injected on one or more occasions, the HIV prevalence among injecting drug users was estimated at 13% (110/836). From the observed HDs 80% were male, with a mean age of 38 years (SD: 7) and a mean age at the onset of drug use of 18 years (SD: 5). All HDs currently injected or had previously injected. The first injected drugs were used at a mean age of 21 years (SD: 6). All HDs used heroine, 84% also used cocaine, 54% were homeless, 91% unemployed and 80% had a history of imprisonment. Further, 71% of the female HDs were prostitutes, 37% of the male ones visited prostitutes, 81% had contracted hepatitis B (of which 20% were a carrier) and all HDs were infected with hepatitis C. An estimate based on prevalence data gave 143/836 (17%) and that based on capture-recapture analysis with two registrations was 102/836 (12%).

The number of HDs was estimated to be 110. The population had a marginalized existence and there was a risk of HIV spreading.