Oral pre-exposure prophylaxis (PrEP) is a recommended component of combination HIV prevention and its availability is rising through demonstration projects and full-scale national programs. In sub-Saharan Africa, young women are a priority population for HIV prevention and targeted to initiate PrEP, given their high HIV incidence rates and promising success from a strategy that can be used without the engagement of male partners. A key question in the field is whether young women using PrEP have ongoing HIV risk and adhere to PrEP sufficiently to have protection from HIV when they have condomless sex with HIV-infected partners. The only true way to know whether a heterosexual woman is sexually exposed to HIV or has a partner with high HIV risk is to test for HIV and STIs in her male partner(s) and quantify HIV viral levels, if any are detected. Yet engaging men in clinic-based HIV testing is challenging. More recent efforts have focused on using HIV self-testing kits to respond to demands on men's time and reluctance to seeking preventive healthcare. The availability of PrEP also provides a new incentive for men to test.

By leveraging an ongoing study of bone health with concurrent use of PrEP and injectable DMPA (often known as Depo Provera® or depot medroxyprogesterone acetate), we have opportunity to engage a new cohort of young men and objectively measure HIV and common STIs in these young men and link the results to women's use of PrEP. The primary objective of this study is to determine whether young women's adherence to PrEP aligns with the HIV status and risk of their male partners. To address its primary objectives, this study will leverage: 1) an ongoing study among young women and 2) a novel cohort of young men who are current sexual partners of the young women in the ongoing study to objectively measure PrEP use, HIV, and HIV factors related to HIV risk. This study will provide a framework for understanding how and when young women and men decide to take PrEP, estimate the proportion of women that are benefitting from HIV protection when they have male partners with or at high risk of acquiring HIV, and provide a novel opportunity to engage young men in PrEP delivery and as supporters of women's PrEP use.

The proposed research will engage a new cohort of young men, whose female partners are already engaged in the Kampala Women's Bone Study. Women in the Kampala Women's Bone Study will be invited to engage in this novel study to recruit their male partners. Women's HIV risk is directly related to the HIV status and risk of their male sexual partners and thus, we will leverage our ongoing cohort of KWBS young women to recruit their male sexual partners for a new men's study. Men will be offered PrEP, diagnostic STI testing and treatment, and followed for 6 months to assess PrEP continuation and STIs. Men's data will be linked to data from their female sex partners in the parallel KWBS study to determine whether women's PrEP use aligns with HIV risk and exposure.

B. Study Aims Aim 1. To determine whether young women's adherence to PrEP aligns with the HIV status of their male partners Men engaging in this study will have HIV testing at enrollment, month 1 and quarterly for up to 6 months. Results from this testing will be linked to data from the participant's female sex partner that characterize her PrEP use to determine whether her PrEP use aligns with his HIV status.

Aim 2. To determine whether young women's adherence to PrEP aligns with the HIV risk of their male partners Men engaging in this study will have testing for common curable STIs (Chlamydia trachomatis and Neisseria gonorrhoeae) at enrollment, month 1 and quarterly for up to 6 months. Results from this testing will be linked to data from the participant's female sex partner that characterize her PrEP use to determine whether her PrEP use aligns with his HIV risk (defined by the results from his STI testing).

Aim 3. To determine whether young men's adherence to PrEP aligns with the HIV status and risk of their female partners We will offer PrEP to HIV-negative men enrolled in this study and track PrEP initiation, refills, and adherence to PrEP (based on self-report and drug levels). The frequency of high PrEP adherence will be compared among men with female partners infected and uninfected with HIV or another STI.

C. Primary exposure The primary exposure is male infection with HIV (Aim 1), NG or CT (Aim 2) and female infection with HIV, NG, or CT (Aim 3).

D. Primary outcomes The primary outcome will be PrEP used by women with sufficient daily adherence to confer HIV protection (6-7 doses in the past week or TFV ≥40ng/mL) for periods when women are dispensed PrEP. When PrEP is not dispensed, the TFV level will be assigned as 0 ng/mL.

For Aim 3, the primary outcome will be PrEP used by men with sufficient daily adherence to confer HIV protection (4 doses in the past

Inclusion Criteria:

• Men ages ≥18
• Has a female sexual partner enrolled in the Kampala Women's Bone Study
• Willing and able to provide informed consent

Exclusion Criteria:

• Has any other condition that would preclude the ability to provide informed consent, make study participation unsafe, complicate the interpretation of study findings or otherwise interfere with achievement of the study objectives, in the investigator's discretion.

Eligibility for women:

Inclusion criteria:

• Participating in the Kampala Women's Bone Study
• Willing to talk with male sex partners about the new study for men and refer men for study recruitment

Exclusion criteria:

• Has concerns about potential social harm stemming from anticipated conversations with male sex partners about the new study for men such that study staff would discourage the women from participation
• Investigator discretion

Six months

Adverse event data were reported spontaneously by participants and not routinely collected.