(Last updated 5/7/2014; last reviewed 5/7/2014)
Testing positive for HIV often leaves a person overwhelmed with questions and concerns. So the first step after testing positive is to see a health care provider.
People with HIV work closely with their health care providers to make important decisions, such as when to start treatment and what HIV medicines to take. Making these decisions begins with a baseline evaluation.
A baseline evaluation includes all the information collected during a person’s initial visits with a health care provider. An HIV baseline evaluation involves a review of the person’s health and medical history, a physical exam, and lab tests.
The purpose of a baseline evaluation is to:
People often ask their health care providers the following questions:
The following tests are conducted as part of a baseline evaluation.
A CD4 count measures the number of CD4 cells in a sample of blood. CD4 cells are infection-fighting cells of the immune system. HIV destroys CD4 cells, which damages the immune system. A damaged immune system makes it hard for the body to fight off infections. Treatment with HIV medicines (antiretroviral therapy [ART]) prevents HIV from destroying CD4 cells.
ART is recommended for everyone with HIV, but the urgency to start ART is greater in people with low or rapidly falling CD4 counts. A falling CD4 count indicates that HIV is advancing and damaging the immune system.
The CD4 count is also used to monitor the effectiveness of HIV medicines once ART is started.
A viral load test measures how much virus is in the blood (viral load). A goal of HIV treatment is to keep a person’s viral load so low that the virus can’t be detected by a viral load test. A high viral load increases the urgency to start ART.
Drug-resistance testing identifies which, if any, HIV medicines will not be effective against a person’s strain of HIV. Drug resistance test results are used to guide selection of an HIV regimen.
Testing for sexually transmitted infections (STIs)
Coinfection with another STI can cause HIV infection to advance faster and increase the risk of HIV transmission to a sexual partner. STI testing makes it possible to detect and treat any STIs promptly.
A baseline evaluation also includes other tests, such as a blood cell count, kidney and liver function tests, and tests for hepatitis.
Before starting treatment, people with HIV must be prepared to take HIV medicines every day for the rest of their lives. A baseline evaluation can help to identify any issues that can make medication adherence difficult, such as lack of health insurance or alcohol or drug abuse. (Medication adherence means taking HIV medicines every day and exactly as prescribed.) Health care providers can recommend additional support to help people deal with these issues before treatment starts.