Preface.- Section 1 Global Epidemiology.- Global epidemiology of Sexually Transmitted Infections in the 21st century: beyond the numbers.- The new epidemiology of Human Immunodeficiency Virus infection.- Social and Behavioral determinats of STI in the 21st century. An overview.- Section 2 Prevention and control of STI.- Behavioral Prevention Strategies for STI.- Vaccines for STIs: present and future directions.- Section 3 Laboratory and diagnostic techniques.- New diagnostic approaches to viral Sexually Transmitted infections .- New tools for the diagnosis of bacterial STIs.- Section 4 The clinical spectrum of STI.- The syphilis after the year 2000.- Neisseria gonorrhoeae infections.- Novel approach to Chlamydia trachomatis Infections in female and male.- Genital Herpes: clinical and scientific novelties.- Clinical Management of anogenital warts and Intraephitelial neoplasia.- Sexually Transmitted Hepatitis.- Bacterial Vaginitis and Vaginosis .- The clinical spectrum of Human Immunodeficiency Virus infection.- Donovanosis, chancroid and endemic treponematoses. Clinical features and control.- The Lymphogranuloma venereum as re-emerged sexually transmitted infection .- HHV-8 Infection and Kaposi Sarcoma .- Section 5 Modern challenges in STI area.- Biological pathways of HPV-induced carcinogenesis .- Antimicrobial resistance of Neisseria Gonorrhoeae: a new challenge.- The men who have sex with men (MSM) as core group for STI .- The vaccines against HPV: a new direction for STI prevention.- Immunological strategies against T. Pallidum infections.- Natural history of anal HPV Infection.