Introduction Comunidades Positivas was a randomised clinical trial that assessed a community-level structural combination HIV prevention intervention for men who have sex with men (MSM) in Peru from 2008–2011. We used a 2 × 2 factorial design to determine the independent and combined effectiveness of community-level behavioural and biomedical HIV/STI prevention interventions.
Methods We cluster-randomised 24 low-income neighbourhoods in Lima, Peru, to one of four conditions: (1) Establishment of Community Centers focused on empowerment and promotion of HIV/STI prevention messages for MSM; (2) Expedited Partner Therapy for bacterial STIs; (3) Both interventions combined or; (4) No intervention. To determine the effectiveness of the interventions, a cohort of participants from each neighbourhood was interviewed concerning sexual risk behaviours and tested for HIV, HSV-2, syphilis, chlamydia and gonorrhoea (pharyngeal and anal) at baseline and 9- and 18-months follow-up visits. We used Poisson regression adjusted for neighbourhood clustering to determine the association of intervention allocation with unprotected anal intercourse (UAI) and overall STI incidence.
Results We enrolled 718 MSM and retained 571 (80%) at 18 months. At baseline there were no differences by intervention arm in either UAI or STI prevalence. The overall STI incidence was 19/100 person years with no difference in STI incidence by intervention allocation (all p > 0.05) (Table 1). There was an 19% absolute reduction in reported UAI in all communities comparing baseline to 18 months. There was no difference in the probability of reporting UAI by intervention allocation at the second follow-up (all p > 0.05) (Table 2).
Conclusions There was no significant intervention effect on STI incidence or UAI. Further analyses to interpret the lack of intervention effectiveness are ongoing and should be considered in future efforts to conceptualise and study the relationship between structural and biomedical components of combination prevention.
- clinical trial
- HIV Prevention