title: The significance of HIV 'blips' in resource-limited settings: is it the same? analysis of the treat Asia HIV Observational Database (TAHOD) and the Australian HIV Observational Database (AHOD).
abstract: BACKGROUND
  Magnitude and frequency of HIV viral load blips in resource-limited settings, has not previously been assessed. This study was undertaken in a cohort from a high income country (Australia) known as AHOD (Australian HIV Observational Database) and another cohort from a mixture of Asian countries of varying national income per capita, TAHOD (TREAT Asia HIV Observational Database).
  
  
  METHODS
  Blips were defined as detectable VL (≥ 50 copies/mL) preceded and followed by undetectable VL (<50 copies/mL). Virological failure (VF) was defined as two consecutive VL ≥50 copies/ml. Cox proportional hazard models of time to first VF after entry, were developed.
  
  
  RESULTS
  5040 patients (AHOD n = 2597 and TAHOD n = 2521) were included; 910 (18%) of patients experienced blips. 744 (21%) and 166 (11%) of high- and middle/low-income participants, respectively, experienced blips ever. 711 (14%) experienced blips prior to virological failure. 559 (16%) and 152 (10%) of high- and middle/low-income participants, respectively, experienced blips prior to virological failure. VL testing occurred at a median frequency of 175 and 91 days in middle/low- and high-income sites, respectively. Longer time to VF occurred in middle/low income sites, compared with high-income sites (adjusted hazards ratio (AHR) 0.41; p<0.001), adjusted for year of first cART, Hepatitis C co-infection, cART regimen, and prior blips. Prior blips were not a significant predictor of VF in univariate analysis (AHR 0.97, p = 0.82). Differing magnitudes of blips were not significant in univariate analyses as predictors of virological failure (p = 0.360 for blip 50-≤1000, p = 0.309 for blip 50-≤400 and p = 0.300 for blip 50-≤200). 209 of 866 (24%) patients were switched to an alternate regimen in the setting of a blip.
  
  
  CONCLUSIONS
  Despite a lower proportion of blips occurring in low/middle-income settings, no significant difference was found between settings. Nonetheless, a substantial number of participants were switched to alternative regimens in the setting of blips.
authors: Monash Medical Centre, Clayton, Victoria, Australia ; Alfred Hospital, Prahran, Victoria, Australia.
authors: Rupa
authors: R
authors: Kanapathipillai
authors: Kirby Institute, The University of New South Wales, Darlinghurst, New South Wales, Australia.
authors: Hamish
authors: H
authors: McManus
authors: University of Malaya Medical Centre, Kuala Lumpur, Malaysia.
authors: Adeeba
authors: A
authors: Kamarulzaman
authors: Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.
authors: Poh Lian
authors: PL
authors: Lim
authors: Kirby Institute, The University of New South Wales, Darlinghurst, New South Wales, Australia ; RPA Sexual Health, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
authors: David J
authors: DJ
authors: Templeton
authors: Kirby Institute, The University of New South Wales, Darlinghurst, New South Wales, Australia.
authors: Matthew
authors: M
authors: Law
authors: Monash Medical Centre, Clayton, Victoria, Australia ; Alfred Hospital, Prahran, Victoria, Australia ; Departments of Medicine and Infectious Diseases, Monash University, Clayton, Victoria, Australia.
authors: Ian
authors: I
authors: Woolley
mesh_terms: D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D001208:Asia; D001315:Australia; D018791:CD4 Lymphocyte Count; D060085:Coinfection; D016208:Databases, Factual; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy / Q000821:virology*; D006526:Hepatitis C / Q000150:complications* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019562:Viral Load; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents