Relationship between HIV and other STIs
Evidence has accumulated over the past two decades regarding the role of genital ulcer diseases (GUD) and other sexually transmitted infections (STIs) in facilitating the sexual transmission of HIV. These STIs boost HIV shedding in the genital tract, which amplifies HIV infectiousness, and increase susceptibility to HIV by recruiting HIV-susceptible inflammatory cells to the genital tract, as well as by disrupting mucosal barriers to infection. In addition, certain STIs, such as herpes simplex virus type 2 (HSV-2), may up-regulate HIV plasma viral load in co-infected persons.
STI treatment interventions have an impact on HIV transmission at the individual level, and can have an impact at the population level, dependent on the specific context. It is important to maintain services for STI control because persons with STIs are at high risk of HIV infection due to high-risk sexual behaviours and the cofactor effect of an existing STI. It is also crucial to establish and maintain a comprehensive package of services for HIV and STI prevention and management.