Sexual network position and risk of sexually transmitted infections
- 1Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- 2Quintus-ential Solutions, Colorado Springs, Colorado, USA
- 3Bixby Center for Global Reproductive Health Research & Policy, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, San Francisco, California, USA
- 4RTI International, San Francisco, California, USA
- 5Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
- Correspondence to Dr C M Fichtenberg, Johns Hopkins Bloomberg School of Public Health, Department of Epidemiology, 615 N Wolfe Street, 6th Floor, Baltimore, MD 21205, USA; cfichten{at}jhsph.edu
- Accepted 4 July 2009
- Published Online First 20 August 2009
Abstract
Objectives: A population-based sexual network study was used to identify sexual network structures associated with sexually transmitted infection (STI) risk, and to evaluate the degree to which the use of network-level data furthers the understanding of STI risk.
Methods: Participants (n = 655) were from the baseline and 12-month follow-up waves of a 2001–2 population-based longitudinal study of sexual networks among urban African–American adolescents. Sexual network position was characterised as the interaction between degree (number of partners) and two-reach centrality (number of partners’ partners), resulting in the following five positions: confirmed dyad, unconfirmed dyad, periphery of non-dyadic component, centre of star-like component and interior of non-star component. STI risk was measured as laboratory-confirmed infection with gonorrhoea and/or chlamydia.
Results: Results of logistic regression models with generalised estimating equations showed that being in the centre of a sexual network component increased the odds of infection at least sixfold compared with being in a confirmed dyad. Individuals on the periphery of non-dyadic components were nearly five times more likely to be infected than individuals in confirmed dyads, despite having only one partner. Measuring network position using only individual-based information led to twofold underestimates of the associations between STI risk and network position.
Conclusions: These results demonstrate the importance of measuring sexual network structure using network data to fully capture the probability of exposure to an infected partner.
Footnotes
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Funding This work was supported by grants from the National Institute for Allergy and Infectious Diseases and the National Institute on Drug Abuse.
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Competing interests None.
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Ethics approval Ethics approval was provided by University of California, San Francisco Johns Hopkins Medical Institutions.
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Patient consent Obtained.
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Contributors: CMF designed and conducted the analyses and wrote the manuscript; BB led data collection in the field; SQM was responsible for network data management and assisted with network analysis; NSP helped design and oversee data collection; TAG advised on the analysis and interpretation, and helped draft the manuscript; JME conceived and conducted the Bayview Networks Study and helped design the analysis and draft the manuscript.
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Provenance and Peer review Not commissioned; externally peer reviewed.
