Incidence of syphilis in a cohort of HIV-infected subjects, Italy

Abstract number: P2151

Matteelli A., Basché R., Carvalho A., Cristini G., Paraninfo G., Caligaris S., Capone S., Castelnuovo F., El Hamad I., Carosi G.

Background and Objective: Syphilis is a reliable marker of behaviours at increased risk for transmission/acquisition of sexually transmitted infections (STI) and HIV. Among HIV infected persons the incidence of syphilis reflects the potential for further spreading of the HIV virus in the community. We measured the incidence of syphilis in a cohort of HIV infected persons and described association with demographic and behavioural variables.

Methods: Retrospective, cohort analysis. All consecutive HIV infected persons registered at the Institute of Infectious and Tropical Diseases, Spedali Civili, Brescia from 1 January 2001 to 30 June 2007 were included. The Institute did not adopt specific strategies to reduce the risk of acquiring /transmitting STIs during the study period. All demographic, behavioural, and syphilis treponemal tests (TPHA) results were collected from clinical charts.

Results: Out of 1905 new HIV infected subjects enrolled during the study period 1280 (67.2%) had at least one TPHA test. A positive syphilis serology at the first test was documented in 238 subjects (18.6%). Of the 1042 remainder subjects 509 (48.8%) had at least one repeated test and were included in the retrospective cohort analysis. 47 (9%) seroconverters were identified over a mean follow-up period of 759 days (SD±668 days). Syphilis incidence was 43.8/1000 person/year (95% CI: 32.0–57.9). At univariate analysis, being male (OR 5.22, 95% CI: 1.84–14.81, p < 0.005) and homo/bisexual (OR 6.24, 95% CI: 3.32–11.72, p < 0.00) were associated with a higher risk of new syphilis infection. Nor age neither virological/immunological parameters were associated with the risk of syphilis. The Cox regression analysis showed that homo/bisexuality was independently associated with an increased risk of syphilis (HR 4.39, 95% CI: 2.33–8.30, p < 0.005).

Comments: In the absence of specific risk reduction programmes the incidence of syphilis remains high among HIV infected homo/bisexual males in Northern Italy. These data document the potential for continuous spread of HIV infection and other STI in this population.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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