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AIDS 2014: Low Level Viral Load Does Not Raise Risk of HIV Treatment Failure


People with HIV who have a low-level viral load between 20 and 50 copies/mL were not more likely to experience virological failure of antiretroviral therapy (ART) compared with those who consistently maintained viral suppression below 20 copies/mL, according to research presented at the 20th International AIDS Conference in Melbourne.

Modern combination antiretroviral regimens can usually produce good viral suppression in most people with HIV. It is well known that viral suppression is associated with CD4 T-cell recovery and reduced HIV disease progression, but the effects of very low levels of HIV RNA are not fully understood, as widely used viral load tests have had a level of detection of 400, 200, and then 50 copies/mL. Current tests can measure down to 20 copies/mL, however, while highly sensitive research assays can detect as little as a single copy.

Ramon Teira and fellow investigators with the Spanish VACH Study Group investigated the implications of very low-level HIV viremia between 20-50 copies/mL. They looked at whether very low viral load was associated with a greater risk of virological failure (defined as 2 consecutive viral loads above 200 copies/mL or 1 such measurement followed by a treatment change) compared with either low-level viral load in the 50-200 copies/mL range or maintaining full suppression below 20 copies/mL.

This analysis included more than 21,000 HIV positive participants in the VACH cohort. More than three-quarters were men and the mean age at diagnosis was 30 years. .

The researchers selected patients who started ART after January 1997 and achieved viral suppression with 2 consecutive viral load measurements below 50 copies/mL, followed by full suppression indicated by at least 1 measurement below 20 copies/mL.


  • Among 21,480 people who started ART, 13,674 (64%) achieved viral suppression below 50 copies/mL.
  • Of these, 6834 people (50%) reached full suppression below 20 copies/mL, including 4289 (31%) who did so after June 2009 (when the 20 copies/mL test came into use).
  • Within the latter group, 2623 (61%) maintained full viral suppression, 824 people (19%) had subsequent viral loads between 20 and 50 copies/mL but not higher, 563 people (13%) had viral loads between 50 and 200 copies/mL but never above 200, and 278 people (6%) ever had viral load above 200 copies/mL.
  • Within the group of 4289, there were 199 cases of virological failure (5%), while 3952 maintained successful treatment.
  • Among the 2623 participants who always had full viral suppression, there were 98 virological failures (4%) and 2489 who maintained successful treatment.
  • Among the 824 people with any episodes of very low-level viral load in the 20-50 copies/mL range, there were 30 virological failures (4%) and 793 who maintained successful treatment.
  • Among the 563 people with any low-level viral loads in the 50-200 copies/mL range, there were 44 virological failures (8%) and 451 who maintained successful treatment.
  • Among 278 people with any viral load measurements above 200 copies/mL, there were 27 virological failures (10%) and 218 who maintained successful treatment.
  • Having only very low-level viral load in the 20-50 copies/mL range was associated with a reduced likelihood of virological failure compared to higher levels (hazard ratio [HR] 0.59, or about a 40% lower risk).
  • Very low-level viral load was not associated with increased failure risk compared to persistent viral suppression below 20 copies/mL.
  • Other predictors of virological failure included lower nadir (lowest-ever) CD4 cell count, shorter duration of viral suppression below 50 copies/mL, and a history of injection drug use.
  • Women and men were equally likely to achieve viral suppression and female sex was not a risk factor for virological failure.

"In the population of HIV-infected patients on ART who achieve full viral suppression below 20 copies/mL, those who experience subsequent episodes of very low levels of viremia(between 20 and 50 copies/mL), the risk of virological not higher than that of patients who remain fully suppressed," the researchers concluded.



R Teira, P Muñoz-Sanchez, I Suarez-Lozano, et al. Effect of viral suppression below 20 copies of HIV-RNA per millilitre of plasma on virological outcome of treated HIV-infected patients. 20th International AIDS Conference. Melbourne, July 20-25 2014. Abstract TUAB0101.