[Sexually transmitted infections in male prison inmates: risk of development of new diseases].

Objective: To measure incidence and main risk factors related to sexually transmitted infections (STIs) in Daroca Prison (Zaragoza, Spain).

Method: A retrospective cohort study (2005-2013) to measure the incidence of STI and a cross-sectional study to measure risk factors.

Results: Of the 203 inmates, 79 developed an STI, 37 had a previous STI, 55.2% lacked knowledge on STI prevention, and 28.9% showed behaviours unfavourable for STI prevention. The incidence rate was 6.5 STIs per 1,000 inmates-year. The most frequent STIs were hepatitis B (39.7%), Ureaplasma urealyticum (19.1%), herpes simplex (16.2%) and HIV (8.8%). The risk (hazard ratio, HR) of acquiring a new STI was significantly higher in inmates with a history of previous STI (HR=2.61; 95%CI: 1.01 to 6.69), and was at the limit of significance for non-preventive behaviour (HR=2.10; 95%CI: 0.98 to 4.53), but not in knowledge related to STIs (HR=1.33; 95%CI: 0.58 to 3.07).

Conclusion: The most important risk factors in prison are behaviours related to STIs and previous history of STIs. Other factors are being a repeat offender, injecting drug use, or being in a methadone programme. Health personnel and peer education can facilitate prevention and control.