Evolucion de la prevalencia de infeccion por virus de la inmunodeficiencia humana en poblacion reclusa al ingreso en prision durante el periodo 1991-1995

Background: Inmates of Spanish prisons include a high number of intravenous drug users (IVDUs) and other people whose practices entail the risk of infection with the human immunodeficiency virus (HIV). The aim of this work is to find out the evolution of the prevalence of HIV infection at the time of admission to prison and the factors associated with it in this population group. This may enable us to form an idea of the effectiveness of risk reduction strategies and help to improve them. Methods: All those people who were placed in a provincial penal institution in the northwest of Spain between 1991 and 1995. Socio-demographic, penal and HIV risk factor variables were gathered. The HIV infection test (ELISA and Western-blot) was carried out with the consent of the subjects. Results: Of the 1,663 people studied, 19.4% were HIV-positive. The prevalence HIV infection was particularly marked statistically in: women (26.0%), the 25-34 age group (29.1%), whites (20.9%), single people (22.8%), those people with a tattoo (29.9%), those people with a background in self-inflicted injuries (42.2%), IVDUs (46.3%), those who admitted sharing syringes (61.5%) and those with a prison record of one or more years (37.3%). Logistical regression analysis showed the following as predictors of HIV infection: IVDUs, those who went to prison in 1992, women, the 25-34 and 35-44 age group, tattooed men, those with a background in self-inflicted injuries and those with a prison record, of more than one year. The gypsy ethnic group revealed a lower probability of HIV infection. The HIV infection time trend, stratified according to the prison record showed an almost significant drop (P = 0.064). The infection trend per IVDU did not show any modification (P = 0.16). Conclusions: A high prevalence of HIV infection was detected in a prison located in a region which has not been particularly affected by AIDS. IVDUs and some characteristics that may be related to this population group have an enormous influence on this phenomenon. The time trend for this infection in this population group has decreased through the lower number of IVDUs that are admitted to prison although very high levels of prevalence of the infection were maintained in this group over the five years of the study. It is recommended that risk-reduction programmes in prisons be fostered (methadone maintenance programmes, syringe exchange pilot programmes).