Cervical dysplasia and invasive carcinoma have been associated with several sexually transmitted agents. The particular agent(s) involved has not yet been definitely identified although data implicating human papilloma virus (HPV) at least in some cases, have become compelling. Data from our study, still in progress, so far have identified HPV 16 or 18, chlamydia trachomatis, and bacterial vaginosis as independently associated with cervical dysplasia in a random sample of women attending a sexually transmitted disease clinic; and show an interesting correlation of past infectious monocleosis with cervical HPV 16/18 infection. Other potential risk factors (eg, smoking, number of sexual partners, HSV-2 infection) were not independent risk factors. Among longitudinally followed cohorts of women, the risk of dysplasia has ben highest among those with HPV infection, especially those with HPV 16/18. Certain patterns were predictive of cervical HPV 16/18 infection. We plan to continue to monitor cervical cytology, densitometry, and analysis of the state of HPV integration into host cell DNA, in the following conditions: cervical infection with HPV 6, 11, 16, 18, or other types, with and without dysplasia; cervical dysplasia without HPV infection; and for comparison, cohorts with first episode genital herpes virus infection; cervical Chlamydia trachomatis infection; and no cervical infection or dysplasia. Data concerning other risk factors, such as smoking, oral contraceptive use, and family history will be collected in conjunction with the above, in an effort to define the natural history of cervical infection with HPV, and with of STDs of interest, in relation to cervical dysplasia.