Is lateral flow test superior to flow-through technology in single-step Human Immunodeficiency Virus (HIV) testing?

Lateral Flow vs Flow-Through Technology for Single-Step HIV Testing

Flow-through technology (INSTI™) demonstrates superior performance to lateral flow assays for single-step HIV testing, particularly in detecting early HIV infection, with significantly faster results (60 seconds vs 15 minutes) and better sensitivity during seroconversion. 1

Performance Comparison in Early HIV Detection

The flow-through INSTI™ HIV-1/HIV-2 test outperforms lateral flow assays in the critical early detection window:

• Flow-through technology became reactive 9 days before Western blot confirmation in seroconversion panels, demonstrating earlier detection capability 1
• When directly compared to FDA-approved antibody-based lateral flow rapid tests, flow-through technology detected significantly more early infections 1
• Among specimens that were Architect-positive but Multispot-negative/indeterminate (representing early infection), flow-through detected 27% (23/85) of cases 1

Sensitivity and Specificity

Both technologies demonstrate excellent performance in established infections, though flow-through maintains an edge:

Flow-through (INSTI™):

• Sensitivity: 99.84% for HIV-1 and 100% for HIV-2 1
• Specificity: 99.80% 1

Lateral flow assays:

• Sensitivity: 99.2-100% in established infections 2, 3
• Specificity: 99.7-99.9% 2, 3

Speed and Practical Advantages

The flow-through technology provides critical time advantages:

• Results available in 60 seconds compared to approximately 15 minutes for lateral flow 1, 4
• This rapid turnaround facilitates immediate clinical decision-making, isolation protocols, and treatment initiation 1

Sample Type Versatility

Both technologies accommodate multiple specimen types:

• Flow-through performs similarly with plasma and simulated whole blood specimens 1
• Lateral flow assays work effectively with serum, plasma, and venous whole blood 2

Clinical Context and Limitations

Important caveats to consider:

• The superior early detection of flow-through technology is most clinically relevant in high-risk populations where catching acute infection matters for transmission prevention 1
• Both technologies maintain >99% sensitivity and specificity in established HIV infection, making the choice less critical for routine screening in low-risk populations 2, 3, 1
• Standard HIV testing protocols still require sensitivity >99% and specificity >99%, which both technologies achieve 4

Recommendation Algorithm

Use flow-through technology when:

• Testing high-risk populations where early detection impacts transmission prevention 1
• Immediate results (within 1 minute) are needed for clinical decision-making 1
• Point-of-care settings require detection of acute/early HIV infection 1

Either technology is acceptable when:

• Screening established infections in routine clinical settings 2, 3, 1
• Cost constraints favor the typically less expensive lateral flow option 3
• Testing low-risk populations where early detection is less critical 4