How Is HIV Diagnosed?

HIV, or Human Immunodeficiency Virus, is a virus that attacks the body’s immune system, specifically targeting CD4 cells (T cells), which are crucial for fighting off infections. Diagnosing HIV involves a series of steps that include testing for the presence of the virus in the body. Here’s a comprehensive overview of how HIV is diagnosed:

Risk Assessment And Symptoms Evaluation

Before testing for HIV, healthcare providers typically conduct a risk assessment to determine a person’s potential exposure to the virus. They may ask about sexual behaviours, drug use (especially injection drugs), previous testing history, and potential exposure to infected bodily fluids. Symptoms associated with HIV, such as fever, fatigue, swollen lymph nodes, and skin rashes, may also be considered.

HIV Antibody Testing

The most common method for diagnosing HIV is through antibody testing. This test detects antibodies the immune system produces in response to HIV infection. The types of antibody tests include:

• ELISA (Enzyme-Linked Immunosorbent Assay): This test detects HIV antibodies in blood, saliva, or urine samples. It is highly sensitive but may produce false-positive results, especially during the window period when antibodies are not yet detectable.
• Rapid HIV Tests: These tests provide results within minutes using blood from a finger prick or oral fluids. They are convenient for quick screening but may require confirmation with a laboratory-based test if positive.
  

  HIV RNA Testing

  Also known as nucleic acid testing (NAT), this method directly detects the presence of HIV RNA (genetic material) in the blood. It is susceptible and can detect HIV earlier than antibody tests, during the acute phase of infection (within 7-28 days post-exposure). NAT is often used with antibody testing for accurate diagnosis, especially in cases of recent exposure.

  Confirmatory Testing

  If an initial antibody test is positive, a follow-up test is done for confirmation. The Western blot and immunofluorescence assay (IFA) are commonly used confirmatory tests that identify specific HIV antibodies in the blood.

  CD 4 Cell Count And Viral Load Testing

  After confirming HIV infection, healthcare providers assess the progression of the disease by measuring CD 4 cell counts and viral load. CD 4 cells are a key indicator of immune health, and a declining count indicates HIV progression. Viral load measures the amount of HIV in the blood and helps determine the effectiveness of antiretroviral therapy (ART).

  Other Tests
  

• Drug Resistance Testing: This test identifies mutations in HIV genes that may cause resistance to certain antiretroviral drugs, guiding treatment decisions.
• Screening for Co-Infections: People with HIV are at higher risk of other infections like hepatitis B and C, so screening for these infections is important for comprehensive care.
• Home Test: HIV can be diagnosed using home testing kits that are approved by regulatory authorities and follow recommended testing protocols. These kits typically involve collecting a blood sample or oral fluid sample at home and then sending it to a laboratory for analysis.
  

  Prevention Counselling And Linkage To Care

  Alongside testing, HIV diagnosis involves counselling on prevention strategies, treatment options, and emotional support. Linkage to HIV care services is crucial for starting antiretroviral treatment early, which improves health outcomes and reduces transmission risk.

Diagnosing HIV involves a multi-step approach, starting with risk assessment, antibody testing, confirmatory tests, and monitoring CD 4 cell counts and viral load. Early diagnosis is key to initiating timely treatment and improving outcomes for individuals living with HIV. Regular testing, especially for high-risk populations, is essential for HIV prevention and early intervention.