Screening and Diagnosis-HIV AIDS

(JAMA 2018;320:379)

• Screen all 13–64 yo at least once, every preg, if new STI dx; screen high risk annually
• HIV Ab/p24Ag (ELISA assay): ⊕ 1–12 wk after acute infxn; >99% Se; 1° screening test
• If ⊕, Ab differentiation assay confirms and differentiates HIV-1 vs. -2 (MMWR 2013;62:489)
• HIV RNA PCR viral load (VL) in plasma; assay range is 20–10 million copies/mL; false ⊕ can occur, but usually low # copies; in contrast, VL should be high (>750 k) in 1° infxn
• CD4 count: not a dx test, b/c can be HIV ⊕ w/ normal CD4 or be HIV ⊖ w/ low CD4