The study is funded through the Office of the Global AIDS Coordinator (OGAC #KE-07-0044). The purpose of this study is two-fold. The first purpose is to see if routine monitoring of the level of HIV virus in the blood (viral load) every six months is superior to monitoring by standard clinical evaluations and or immune status (CD4 count) with intermittent viral load monitoring in adults receiving antiretroviral therapy (ART). The second purpose is to understand the cost implications and possible benefits of routine HIV viral load monitoring.

The Kenya Ministry of Health (MoH) guidelines for antiretroviral therapy (ART) and manual for ART providers recommend targeted viral load monitoring in ART management. While only limited use of viral load monitoring exist due to limitations in technical and financial resources, the feasibility and cost-effectiveness of viral load monitoring has not been prospectively studied in ART roll-out at the clinic level.

"Clinic-based ART Diagnostic Evaluation" (CLADE) is an unblinded, randomized (1:1), prospective, observational, cohort public health evaluation (PHE) aimed at evaluating the superiority and cost-effectiveness of two recommended Ministry of Health ART diagnostic evaluation approaches at the clinic level in adult treatment naive patients beginning Ministry of Health approved first-line ART: "routine care", the most common approach to ART roll-out where clinical (World Health Organization) staging and immunological (CD4) monitoring are the primary baseline and follow-up evaluations and targeted viral load monitoring; and "viral load care", where routine viral loads are included with clinical and immunological evaluations.

In this study we plan to enroll 820 adult participants starting ART, 410 people will be enrolled in each of the public health evaluation arms. Arm A/ "routine care" will receive MoH standard of care monitoring consisting of baseline CD4 and WHO staging every 6 months, or as clinically indicated, with CD4 and WHO staging criteria guiding care and treatment in addition to routine clinical evaluations. In addition, MoH criteria for targeted viral load monitoring will be used. Arm B/ "viral load guided care" will receive MoH standard of care as in Arm A but also have routine viral load monitoring at baseline and every 6 months, or as clinically indicated, to guide care and treatment. Each arm will receive Kenya Ministry of Health first-line ART. Participants meeting MoH criteria for treatment failure will being second-line ART.

Inclusion Criteria:

• Male or female > 18 years of age at the time of consent.
• Identified by clinic staff as intending to start ART at the next clinic visit
• Provision of informed consent in either Kiswahili, Luo or English

Exclusion Criteria:

• Any reason (medical, physical location of home relative to clinic, or other) existing that the ART team feel will prohibit the volunteer from coming for routine ART clinic visits.
• Any reason (medical, social, or other) existing that the ART team or study team feel may present a risk to the participant that outweighs the benefit of participating in the study.
• Pregnancy (confirmed or suspected) at time of enrollment.