Laboratoriumsurveillance van HIV-infecties, regio Arnhem, 1989-1995

As from April 1989, surveillance-activities of HIV infections are carried out in the Arnhem area. These programmes are executed in collaboration of the National Institute of Public Health and the Environment (RIVM) with the Regional Public Health Laboratory Arnhem (RPHL)/Rijnstate hospital. This report presents results up to the end of 1995 of monitoring laboratory diagnostics of HIV infections, in addition to a continuous questionnaire on the indication for testing sent to the requesting physicians. Between April 1989 and December 1995 21,825 HIV tests were performed in 19,216 individuals living in the service area. The percentage of positive tests (1.8%, n=386) was almost twice the percentage of positive persons (1.0%, n=186). No increase in number of new infections was observed over time, although the number of requested tests increased up until 1994. Most test requests concerned tests for 'changing heterosexual contacts'. In men, most infections occurred among homo/bisexuals. This was 8-9% up until 1994 but decreased to 3.4% in 1995. 4.4% of the tested female drug users was seropositive ; among males it increased from 3.9% in 1991 to 12% in 1995. No trend in heterosexually acquired infections could be seen over the observed six years. It appears that the spread of HIV is still restricted to the known risk groups: signs for considerable spread in the general population could not be found. Remarkably the percentage of new seropositives seems to decrease in the urban areas whilst it still increases in the rural areas. Furthermore requests for tests of persons originating from Africa and Latin-America increased as does the percentage seropositive tests. Laboratory-based surveillance is thought to be very useful as an indicator of the extent of the problem and monitoring of trends. The methodology used in this surveillance will be used for other regions and infectious diseases.