STIs can be transmitted in a variety of ways. The most common route of infection is through unprotected or inadequately protected sexual intercourse, via vaginal, anal or oral penetration, but also via "fondling" for certain viruses that can be transmitted through the skin. There are several ways to protect yourself during intercourse. Systematic condom use (external or internal) is the best way to protect against STIs. Many STIs can be transmitted through blood, for example by sharing injection equipment. Mothers-to-be can transmit diseases to their babies, either during pregnancy or at the time of delivery. Regular screening is important to ensure effective treatment and prevent transmission of infections.

For further information, we recommend that you consult :

- Santé Publique France's "Question Sexualité" website
- The Santé Publique France website, with its thematic dossier on all STDs/STIs
- Sexuality between men and prevention" information website
- Regional COREVIH websites
- The Ministry of Solidarity and Health website, and the article "Informing people about HIV/AIDS and other sexually transmitted infections (STIs)".
- The STD / STI section on the Assurance Maladie Ameli website

And more specifically for AIDS, you can consult Sida Info Service website.