Drug injection and HIV prevalence in inmates of Glenochil prison.

Objective: To determine prevalence of HIV infection and drug injecting behaviour among inmates of Glenochil Prison on a specified date a year after an outbreak of hepatitis B and HIV infection.
Design: Cross sectional: voluntary, anonymous HIV salivary antibody surveillance and linked self completion questionnaire on risk factors.
Setting: Glenochil prison, Scotland, a year after an outbreak of hepatitis B and HIV transmission related to drug injection.
Subjects: 352 prisoners, of whom 295 (84%) took part; 284 questionnaires (96%) passed logical checks.
Main Outcome Measures: HIV prevalence; proportion of all inmates who had ever injected drugs, had ever injected inside prison, had started injecting drugs while inside prison.
Results: More than half (150/284) the current inmates were also in Glenochil Prison during the critical period of January to June 1993, when hepatitis B and HIV were transmitted. Similar proportions of current inmates and men who were also in Glenochil during the critical period were drug users (27% (75/278) v 30% (44/149)). A quarter of injecting drug users (18/72) had first injected inside prison, irrespective of whether they were in Glenochil in January to June 1993 and regardless of the calendar period when they first injected. Significantly more inmates from Glasgow (41%; 56/138) than from Edinburgh (21%; 7/34) or elsewhere (11%; 12/106) were injecting drug users. On testing for HIV, seven saliva samples out of 293 gave positive results--four were presumed to be from inmates known to be infected with HIV, and the others from injecting drug users from Glasgow, all of whom had been in Glenochil during January to June 1993, when two of the three had injected drugs and had been tested for HIV, with negative results. The ratio of overall (2.4%) to disclosed (1.4%) HIV prevalence was 1.7. For men who had injected drugs in Glenochil during January to June 1993, HIV prevalence was estimated at 29%.
Conclusion: Between a quarter and a third of prisoners who injected drugs in Glenochil in January to June 1993 were infected with HIV. There is widespread ongoing risk of bloodborne virus infection within prisons, which is probably long standing but demands urgent attention.