title: Core group approach to identify college students at risk for sexually transmitted infections.
abstract: OBJECTIVE
  To analyze the core group for sexually transmitted infections (STI) among college students.
  
  
  METHODS
  Cross-sectional study carried out in a convenience sample comprising 711 college students of the public university of Morelos, Mexico, between 2001 and 2003. Sociodemographic and sexual behavior information were collected using self-applied questionnaires. Herpes simplex 2 (HSV-2) infection was tested in the blood. The number of sexual partners in the last year and cocaine consumption were used as indicators to construct the dependent variable "level of STI risk" in three categories: low, medium and high risk (core group). A multinomial analysis was conducted to evaluate whether different sex behaviors were associated with the variable "level of STI risk".
  
  
  RESULTS
  There was significant association between HSV-2 seroprevalence and the variable "level of STI risk": 13%, 5.6% and 3.8% were found in high (core group), medium and low categories, respectively. There were gender differences regarding the core group. Men started having sexual intercourse earlier, had more sex partners, higher alcohol and drug consumption, higher frequency of sex intercourse with sex workers, exchanging sex for money, occasional and concurrent partners compared to women.
  
  
  CONCLUSIONS
  The study findings suggest existing contextual characteristics in the study population that affect their sex behavior. In Mexico, the cultural conception of sexuality is determined mainly by gender differences where men engage in higher risky sexual behavior than women.
authors.affiliation: Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Sánchez-Alemán
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Conde-Glez
authors.forename: Felipe
authors.initials: F
authors.lastname: Uribe-Salas
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D015153:Blotting, Western; D004812:Epidemiologic Methods; D005260:Female; D006558:Herpes Genitalis / Q000175:diagnosis / Q000453:epidemiology*; D018258:Herpesvirus 2, Human / Q000276:immunology*; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D012309:Risk-Taking; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D012749:Sexually Transmitted Diseases / Q000453:epidemiology; D012959:Socioeconomic Factors; D013334:Students / Q000706:statistics & numerical data*
chemical_list: D000914:Antibodies, Viral