Objectives: To support already established epidemiological links between inmates of Glenochil prison positive for HIV infection by using molecular techniques and thus provide evidence of the extent of acquisition during a recent outbreak of the disease resulting from needle sharing. To identify possible sources of the outbreak, and to demonstrate the ability of the methodology to make further links beyond the original outbreak.
Design: Viral sequences obtained from the blood of HIV positive prisoners previously identified by standard epidemiological methods were compared with each other and with sequences from other Scottish patients.
Setting: Glenochil prison for men, central Scotland.
Subjects: Adult inmates and their possible contacts.
Results: Phylogenetic analysis of viral sequences in two different genomic regions showed that 13 of the 14 HIV positive prisoners had been infected from a common source. Previous research had shown that six of these had acquired their infection in Glenochil; molecular evidence suggests that more than double this number were infected while incarcerated. Virus from two long term HIV positive patients who were in the prison at the time of the outbreak but who were not identified in the original or subsequent surveys was sufficiently different to make it unlikely that they were the source. A viral sequence from heterosexual transmission from one inmate showed the ability of these techniques to follow the infection through different routes of infection.
Conclusion: The number of prisoners infected with HIV during the 1993 outbreak within Glenochil prison was more than twice that previously shown. This shows the potential for the spread of bloodborne diseases within prisons by injecting drugs.