HIV Screening Test

HIV Screening Test 

The HIV screening test is used to detect the presence of Human Immunodeficiency Virus (HIV), which attacks the immune system and can lead to Acquired Immunodeficiency Syndrome (AIDS). Early detection through screening is critical for timely treatment and reducing transmission. 

1. What Does the HIV Screening Test Measure? 

• Most commonly, a combination test (HIV-1/2 Antigen and Antibodies) is used to detect both: 

  - HIV-1 and HIV-2 antibodies (produced in response to infection) 

  - p24 antigen (a protein present early after HIV infection) 

• Some tests may also include nucleic acid testing (NAT) for early detection. 

2. Why Is the HIV Screening Test Performed? 

• To diagnose HIV infection early. 

• As part of routine health screening, especially for sexually active individuals or pregnant women. 

• After potential exposure to HIV (e.g., unprotected sex, needle sharing). 

• Prior to surgery, blood donation, or initiating certain treatments. 

3. When Should You Be Tested? 

• At least once for everyone between ages 13 and 64 as part of routine care. 

• More frequently for people with risk factors (e.g., men who have sex with men, multiple partners, injection drug use). 

• Immediately after potential exposure, with follow-up testing if needed. 

4. Interpreting Results 

🔹 Negative (Non-Reactive): No HIV antibodies or antigens were detected. This usually means no infection, though early infection can't be ruled out if testing was done during the window period. 

🔹 Positive (Reactive): HIV antibodies and/or antigen were detected. Additional confirmatory testing (e.g., Western blot, HIV-1/HIV-2 differentiation test) is performed to confirm the diagnosis. 

5. What Is the Window Period? 

• The window period is the time between potential HIV exposure and when the test can reliably detect infection. 

• Most combination antigen/antibody tests can detect HIV within 2–6 weeks after exposure. 

6. How Is the Test Performed? 

• Blood sample (from a vein or fingerstick) or oral fluid sample may be collected. 

• Rapid tests can provide results in 20–30 minutes, while lab-based tests may take 1–2 days. 

7. When to See a Doctor 

🚨 Contact your healthcare provider if you: 

• Think you may have been exposed to HIV. 

• Have flu-like symptoms within 2–4 weeks of possible exposure (acute HIV). 

• Receive a positive screening test result. 

🔹 Key Takeaways 

✅ HIV screening is a crucial step in early diagnosis and prevention of HIV transmission. 

✅ Modern tests can detect infection early and guide timely treatment. 

✅ A positive test result always requires confirmation through additional testing.