Efficacy Study of the Vaginal Gel Carraguard to Prevent HIV Transmission

Inclusion Criteria: * HIV negative and agree to be tested for HIV and told their results at all visits during the study * Aged 16 - 40 years of age * Have had at least one vaginal intercourse within the last three months * Willing and able to give written informed consent (or if desired, consent provided by parent or guardian with written assent from the minor participant) * Provide locator information to study staff throughout the trial * Comply with all aspects of the study protocol, including random assignment to the Carraguard® plus condom or placebo plus condom arm, clinical valuations, specimen collection and testing, visit schedule and study drug regimen * Citizen or permanent resident of South Africa * Resident for the past year and intends to reside in the catchment area of the site for the next two years * During the study, will not use any vaginal products except tampons or those prescribed or approved by the study clinician. Exclusion Criteria: * Currently pregnant, or indicate a desire to become pregnant in the next two years at the time of screening * Within four weeks of last pregnancy outcome at the time of enrolment * Pap smear at screening is graded as carcinoma. * Injected illicit drugs in the 12 months prior to screening * Participating in any other clinical trial/HIV prevention study