Table 1

Definitions of plasma HIV-1 RNA detection during ART according to different guidelines and the Low-Level HIV Viremia Consensus Panel

	EACS4	JAMA/IAS5 6	HIVinfo.gov/DHHS8	WHO7	LLHV-CP
Residual viremia	Not defined	HIV RNA levels>20 and <50 copies/mL6	Not defined	Not defined	Quantifiable HIV-1 RNA levels below 50 copies/mL.
Low-level viremia	HIV RNA levels>51 and <200 copies/mL	HIV RNA levels 50–200 copies/mL5 6	Confirmed detectable HIV RNA levels<200 copies/mL	HIV RNA levels 50–1000 copies/mL	≥2 consecutive HIV RNA measurements between 50 and 500 copies/mL.
Viral blip	Not defined	An outlier increase in HIV RNA levels to<1000 copies/mL that returns to undetectable levels5	After vs, an isolated detectable HIV-RNA level that is followed by a return to vs	An isolated HIV-RNA measurement of 50–1000 copies/mL with a return to suppressed levels	A single HIV-1 RNA measurement between 50 and 1000 copies/mL with adjacent measurements<50 copies/mL.
Viral rebound	Confirmed HIV RNA levels>50 copies/mL in someone with previously undetectable viremia	Not defined	After vs, confirmed HIV RNA levels≥200 copies/mL	Not defined	Confirmed HIV-1 RNA>50 copies/mL following previously suppressed viremia.

ART, antiretroviral therapy; DHHS, Department of Health and Human Services; EACS, European AIDS Clinical Society; JAMA/IAS, Journal of American Medical Association/International Antiviral Society; LLHV-CP, Low-Level HIV-1 Viremia Consensus Panel; VS, viral suppression.