Objectives: To describe knowledge and attitudes regarding sexually transmitted diseases (STD) in the same women followed longitudinally for 7 years from teenage years to early adulthood, and to relate the findings to sexual behaviour. Methods: A face to face interview and a questionnaire were completed by 79 young women when they were, 16, 18, and 23 years old. Results: The questionnaire, testing knowledge about the mode of transmission and prevention of STD, gave a total score of correct answers varying between 44% and 64%, with less knowledge about human papilloma (HPV) an herpes viruses than about chlamydia. Awareness of the possibility of asymptomatic transmission was low. The highest scores were obtained at the age of 18 years Experience of many partners, a history of STD, smoking: and more frequent use of alcohol were associated with a higher level of knowledge. Conclusions: Knowledge was fairly good and consistent, but was more often incorrect regarding viral infections and the possibility of asymptomatic transmission, and in total did not ensure an adequate protective behaviour. A higher level of knowledge was associated with a more risky behaviour, indicating that information was best received by those who could identify with the problem.
