Standard Blood Tests for Sexually Transmitted Disease Screening
Blood tests for STD screening typically include tests for HIV, syphilis, and hepatitis B, which are the primary sexually transmitted infections that can be reliably detected through blood testing. 1
Core Blood Tests for STD Screening
HIV Testing
- Initial screening: Enzyme-linked immunosorbent assay (ELISA) or rapid assay
- Confirmatory test: Western blot or other supplemental test if initial screening is positive
- Important considerations:
- HIV antibodies are detectable in ≥95% of patients within 6 months of infection
- Negative tests cannot rule out infections acquired within the past 6 months
- Informed consent must be obtained before testing 1
Syphilis Testing
- Screening test: Serologic testing using Rapid Plasma Reagin (RPR) or similar test
- Confirmatory test: If screening is positive, confirmatory testing is required
- Testing frequency: Annual testing for those at risk, with more frequent testing (every 3-6 months) for high-risk individuals 1
Hepatitis B Testing
- Standard tests: Hepatitis B surface antigen (HBsAg)
- Additional markers: May include hepatitis B core antibody and surface antibody tests to determine infection status or immunity
- Testing frequency: Annual testing for individuals at risk for STIs, with more frequent testing (every 3-6 months) for high-risk individuals, particularly injection drug users and men who have sex with men 2
Additional Considerations
Testing Frequency
- Annual testing is recommended for individuals at ongoing risk
- More frequent testing (every 3-6 months) is recommended for high-risk individuals 2
Special Populations
Pregnant Women
Pregnant women should receive comprehensive STD screening including:
- Serologic test for syphilis during early pregnancy
- Hepatitis B surface antigen testing
- HIV testing, particularly for those with risk factors 1
High-Risk Individuals
For individuals at higher risk (multiple partners, men who have sex with men, injection drug users):
- More frequent testing is recommended
- Additional testing sites (pharyngeal, rectal) may be needed for comprehensive screening 3, 4
Common Pitfalls to Avoid
- Inadequate follow-up: Ensuring proper linkage to care for positive results is essential
- Incomplete testing: Not testing all relevant anatomical sites in high-risk individuals
- Infrequent testing: Not repeating testing in high-risk individuals even when initial results are negative 2
- Missing the window period: Failing to recognize that negative tests cannot rule out recent infections
Emerging Testing Options
- Combined HIV and syphilis tests using a single finger prick blood sample are under evaluation
- Self-collection options are becoming more available, which may increase testing rates 5, 6
Blood testing is only one component of comprehensive STD screening. For complete STD screening, additional tests including urine samples and swabs from other sites (pharyngeal, rectal) may be necessary depending on sexual practices and risk factors.