Incident Risk Factors as Predictors of HIV Seroconversion in the Lisbon Cohort of Men Who Have Sex with Men: First Results, 2011-2014

HIV incidence in men who have sex with men (MSM) is increasing in western countries, including Portugal. We aimed to estimate HIV incidence and to assess how individual short-term changes in exposures over time predict seroconversion. 

We evaluated participants of an open cohort of HIV-negative MSM enrolled after testing at a community-based voluntary HIV counselling and testing centre in Lisbon. At each evaluation a structured questionnaire was completed and HIV status was ascertained using rapid followed by confirmatory testing. 

Between April 2011 and February 2014, 804 MSM were followed for a total of 893 person-years. Predictors of HIV seroconversion were identified using Poisson generalised linear regression. The overall seroincidence was 2.80/100 person-years (95% confidence interval: 1.89-4.14). 

• Men who seroconverted had a higher mean number of tests per year. 
• Seroconversions were significantly associated with 
• partner disclosure of HIV status during follow-up, 
• newly-adopted unprotected anal intercourse (UAI) with a steady partner and 
• being newly-diagnosed with syphilis during follow-up. 
• Likewise, sexual intercourse with HIV-positive men, having an HIV-positive steady partner at least once during follow-up and persistent UAI with occasional partners were predictors of seroconversion. 

High HIV incidence in this cohort is likely driven by short-term contextual and behavioural changes during follow-up.

Below:  Stratified analysis of the main determinants of HIV incidence by HIV status of steady partner, cohort of men who have sex with men, Lisbon, Portugal, 2011–2014 (n=804)

Full article at: http://goo.gl/AsmEdB

By: Meireles P1, Lucas R, Carvalho C, Fuertes R, Brito J, Campos MJ, Mendão L, Barros H.

• 1EPIUnit, Institute of Public Health, University of Porto, Porto, Portugal. 

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