The European Journal of Public Health Advance Access published online on September 18, 2009
The European Journal of Public Health, doi:10.1093/eurpub/ckp142
Increased sexually transmitted infection incidence in a low risk population: Identifying the risk factors
Frances Shiely1,2, Mary Horgan3 and Kevin Hayes4,5
1 Department of Epidemiology and Public Health, University College Cork, Cork, Ireland
2 Centre for AIDS and STD Research, University of Washington, Seattle, USA
3 Department of Infectious Diseases, Cork University Hospital, Cork, Ireland
4 Department of Mathematics and Statistics, University of Limerick, Limerick, Ireland
5 Department of Statistics, University of Washington, Seattle, USA
Correspondence: Dr Frances Shiely, Department of Epidemiology and Public Health, University College Cork, Brookfield Health Sciences Complex, College Road, Cork, Ireland, tel: +353-21-4901592, fax: +353-21-4901604, e-mail: f.shiely{at}ucc.ie
Received April 30, 2009 , accepted August 18, 2009
Background: Between 1994 and 2006, the incidence of sexually transmitted infections (STIs) in Ireland has increased by over 300%. Recent literature would suggest that this figure is an underestimation of the true scale of infection. Our objective was to determine the risk factors associated with STI diagnosis in a population with a rapidly increasing STI incidence. Methods: Using diagnostic, demographic and behavioural information from three STI clinics (January 1999 to December 2006), multivariable logistic regression models were used to identify risk factors associated with STI diagnosis. Results: Age, smoking and inconsistent condom use are the dominant risk factors. Males aged 20–24 years and females aged <20 years being at greatest risk of STI acquisition. Having three or more partners was not associated with an elevated risk of STI diagnosis. At univariate level, homosexuals and bisexuals have a decreased risk of STI acquisition compared with heterosexuals. Rate of consistent condom use was low 
13.3%. Conclusions: Age, condom use and number of sexual partners are important risk factors for STI diagnosis. Contrary to international STI literature, having multiple sexual partners does not increase STI incidence. Age specific behavioural interventions that target increased condom use may be effective in reducing STIs in Ireland. At policy level, a reduction in the taxation on condoms from 13.5 to 5% is needed to lower the prohibitive cost and increase their use.
Keywords: epidemiology, genitourinary medicine, risk factors, sexually transmitted infections.