HIV Screening Algorithm: Study Flow
Original bench-card visual for reviewing the common HIV laboratory screening flow: Ag/Ab screen, differentiation assay, and NAT follow-up concept.
HIV screening study flow: screen, differentiate, resolve
This is an educational review of laboratory logic. Real reporting follows the current testing algorithm, assay instructions, and facility SOP.
A reactive screen starts the algorithm. It is a screening result and needs the next step defined by the laboratory workflow.
Differentiation testing helps sort antibody reactivity patterns. Interpret with the exact assay and current algorithm.
NAT is used in defined follow-up situations, especially discordant patterns. Keep wording tied to the validated workflow.
A reactive screen starts the algorithm. It is a screening result and needs the next step defined by the laboratory workflow.
Differentiation testing helps sort antibody reactivity patterns. Interpret with the exact assay and current algorithm.
NAT is used in defined follow-up situations, especially discordant patterns. Keep wording tied to the validated workflow.
HIV algorithm study anchors
| Visual clue | Meaning | Student shorthand |
|---|---|---|
| Nonreactive screen | No screen reactivity | Report by assay language |
| Reactive screen | Needs algorithm follow-up | Move to differentiation step |
| Differentiation reactive | Antibody pattern identified | Use current reporting algorithm |
| Screen reactive, differentiation nonreactive or indeterminate | Discordant pattern | NAT follow-up concept |
HIV screening study guide
| Pattern | What to call it | How to think about it |
|---|---|---|
| Ag/Ab nonreactive | Screen nonreactive pattern | Report according to assay wording |
| Ag/Ab reactive plus differentiation reactive | Confirmed algorithm pattern | Use current reporting language |
| Ag/Ab reactive plus differentiation nonreactive | Needs NAT resolution | Follow the lab algorithm |
| Indeterminate pattern | Unresolved by current step | SOP defines repeat or follow-up |
- Think screen, differentiate, resolve.
- Reactive screening results need algorithm completion.
- Keep result language tied to the assay and SOP.
HIV lab logic is screen first, differentiate next, NAT when the algorithm needs resolution.