Engagement in human immunodeficiency virus care: linkage, retention, and antiretroviral therapy adherence.

Effective human immunodeficiency virus (HIV) care in the modern antiretroviral therapy (ART) era requires early entry into and retention in care. Early initiation and adherence to ART therapy improves outcomes. Many evidence-based tools and behavioral interventions are available to optimize adherence to care and ART and can be implemented in clinical settings. Monitoring care engagement and ART adherence creates the opportunity to intervene and prevent virologic failure or loss to follow up. Special HIV-infected populations, such as pregnant and mentally ill patients, require enhanced surveillance and care.