How to test for the four items of infectious diseases

The four-item infectious disease screening involves blood sampling and testing, which includes the following steps: clarifying the purpose of testing, preparing before the test, standardized blood collection, laboratory analysis, and interpreting results. It is an important method for screening common infectious diseases. Individuals with a history of high-risk exposure or abnormal test results should seek timely medical consultation for further diagnosis.

1. Clarify the testing purpose: The four-item infectious disease panel includes tests for hepatitis B, hepatitis C, HIV (AIDS), and syphilis, used to screen for infection with these pathogens. It applies to preoperative screening, blood donation checks, and post high-risk behavior evaluations, helping with early detection and intervention.

2. Prepare before testing: Fasting is not required before the test; maintain normal diet and daily routines, and avoid alcohol consumption and strenuous exercise. Inform your doctor about any history of high-risk exposure, past medical conditions, and current medications to help determine the appropriate timing and accurate interpretation of test results.

3. Standardized blood collection: A healthcare professional collects venous blood from the antecubital vein in the arm. The skin is disinfected prior to sampling. Afterward, apply pressure to the site for 5–10 minutes to prevent bleeding or hematoma. The procedure is quick and minimally invasive.

4. Laboratory testing: The collected blood sample is sent to a laboratory, where pathogen markers such as antigens and antibodies are detected using methods like enzyme-linked immunosorbent assay (ELISA) and nucleic acid testing (NAT). Testing turnaround times vary slightly by item, but results are typically available within 1–3 working days.

5. Interpreting results: A negative result usually indicates no infection or presence during the window period. A positive result requires confirmatory testing—such as quantitative hepatitis B serology or HIV nucleic acid testing—to rule out false positives and accurately determine infection status and disease progression.

If results are abnormal, follow medical advice for targeted treatment: antiviral therapy for hepatitis B or C, antibiotic treatment for syphilis, and long-term, standardized antiretroviral therapy for HIV. For self-care, maintain regular作息 (sleep-wake cycles), avoid fatigue, eat a light diet, abstain from smoking and alcohol, practice personal protection, and undergo regular follow-up testing to monitor disease status.