Clin Infect Dis 2019 Apr 12. Epub 2019 Apr 12.
Division of STD Prevention, National Center for HIV, Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta GA.
Background: Interventions to prevent HIV in women include screening, partner notification, promoting condoms, and pre-exposure prophylaxis (PrEP). Identifying a woman's risk of acquiring HIV can help guide intervention recommendations.
Methods: We used data from Louisiana's STI and HIV registries to study 13- to 59-year-old women following their first diagnosis of syphilis, (or if none) gonorrhea, or (if none) chlamydia during 2000-2015. We measured rates of HIV reported subsequent to their STI (through 2016). Rates for women without STI were estimated by subtracting women with STI from reported cases and from Census estimates for the population. PrEP cost was estimated as $11,000 per year, and effectiveness was estimated as 100%.
Results: First STI were: syphilis (6,574), gonorrhea (64,995), or chlamydia (140,034). These 211,603 women had 1,865,488 person-years of follow-up and 969 HIV diagnoses. Women with no STI had 5,186 HIV diagnoses over 24,359,397 person-years. Rates of HIV diagnosis (per 100,000 person-years) were higher for women after syphilis (177.3), gonorrhea (73.2), or chlamydia (35.4) compared to women with no STI (22.4). Providing PrEP to all women diagnosed with syphilis or gonorrhea would cost $7,371,111,000 and could have prevented 546 HIV diagnoses. Limiting PrEP to one year after syphilis or gonorrhea diagnosis would cost $963,847,334 but only 143 HIV diagnoses were within 2 years after a syphilis or gonorrhea diagnosis.
Conclusions: Rates of HIV diagnosis were high after women had STI, but not high enough to make PrEP cost-effective for them. Most women diagnosed with HIV did not have previously reported STI.