Related Experiment Video
Updated: Mar 27, 2026

An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings
Published on: March 30, 2014
High adherence to oral daily PrEP in a real-world implementation project in Kenya: a brief communication
Ivan Segawa1, Linxuan Wu2,3, Josephine Odoyo4
1Clinical Epidemiology Unit, Makerere University, Kampala, Uganda. ivansegy@gmail.com.
Abstract:
Objective biomarkers of oral pre-exposure prophylaxis (PrEP), such as tenofovir diphosphate (TFV-DP) in dried blood spots (DBS), remain critical for interpreting PrEP adherence. We tested 195 DBS randomly collected from 168 of 4,955 PrEP clients returning for refills at 25 public HIV clinics in Kenya. DBS were extracted using the 50:50 methanol: water method, and drug concentrations quantified using liquid chromatography-tandem mass spectrometry. Optimal adherence was defined as ≥ 900 fmol/punch, corresponding to ≥ 4 doses/week. TFV-DP was detectable in 96% (188/195) of samples; 71% (138/195) had optimal adherence, higher among older clients and men. Optimal adherence is achievable in real-world PrEP programs.
Related Concept Videos
Transmission-based Precautions I: Contact, Enteric, and Droplets
Contact Precautions:
Contact precautions are the measures taken to prevent the transmission of infectious agents, especially epidemiologically important microorganisms such as MRSA or influenza, primarily transmitted through direct or indirect contact with an...
Oral Drug Delivery Systems: Introduction
Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
Handwashing II: Pre-procedure and Initial Procedure Steps
The hand washing procedure itself includes the following steps. First, cover cuts, if any, on hands with a waterproof dressing. Cuts and abrasions can become contaminated with bacteria hindering the ability to clean the area thoroughly. In addition, repeated hand washing can worsen an injury. The nails must be short and clean, without nail...
Oral Drug Delivery Systems: Delayed-Release Systems
Bioavailability Study Design: Healthy Subjects Versus Patients

