title: Lack of awareness of treatment failure among HIV-1-infected patients in Guinea-Bissau - a retrospective cohort study.
abstract: BACKGROUND
  With more people receiving antiretroviral treatment (ART), the need to detect treatment failure and switch to second-line ART has also increased. We assessed CD4 cell counts (as a marker of treatment failure), determined the rate of switching to second-line treatment and evaluated mortality related to treatment failure among HIV-infected patients in Guinea-Bissau.
  
  
  METHODS
  In this retrospective cohort study, adult patients infected with HIV-1 receiving ≥6 months of ART at an HIV clinic in Bissau were included from June 2005 to July 2014 and followed until January 2015. Treatment failure was defined as 1) a fall in CD4 count to baseline (or below) or 2) CD4 levels persistently below 100 cells/µL after ≥6 months of ART. Cox hazard models, with time since six months of ART as the time-varying coefficient, were used to estimate the hazard ratio for death and loss to follow-up.
  
  
  RESULTS
  We assessed 1,591 HIV-1-infected patients for immunological treatment failure. Treatment failure could not be determined in 594 patients (37.3%) because of missing CD4 cell counts. Among the remaining 997 patients, 393 (39.4%) experienced failure. Only 39 patients (9.9%) with failure were switched from first- to second-line ART. The overall switching rate was 3.1 per 100 person-years. Mortality rate was higher in patients with than without treatment failure, with adjusted hazard rate ratios (HRRs) 10.0 (95% CI: 0.9-107.8), 7.6 (95% CI: 1.6-35.5) and 3.1 (95% CI: 1.5-6.3) in the first, second and following years, respectively. During the first year of follow-up, patients experiencing treatment failure had a higher risk of being lost to follow-up than patients not experiencing treatment failure (adjusted HRR 4.4; 95% CI: 1.7-11.8).
  
  
  CONCLUSIONS
  We found a high rate of treatment failure, an alarmingly high number of patients for whom treatment failure could not be assessed, and a low rate of switching to a second-line therapy. These factors could lead to an increased risk of resistance development and excess mortality.
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.|Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark; sanne.jespersen@clin.au.dk.
authors.forename: Sanne
authors.initials: S
authors.lastname: Jespersen
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.|Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark;|Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Bo Langhoff
authors.initials: BL
authors.lastname: Hønge
authors.affiliation: National HIV Programme, Ministry of Health, Bissau, Guinea-Bissau.
authors.forename: Candida
authors.initials: C
authors.lastname: Medina
authors.affiliation: National HIV Programme, Ministry of Health, Bissau, Guinea-Bissau.
authors.forename: David
authors.initials: D
authors.lastname: da Silva Té
authors.affiliation: National HIV Programme, Ministry of Health, Bissau, Guinea-Bissau.
authors.forename: Faustino Gomes
authors.initials: FG
authors.lastname: Correira
authors.affiliation: Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark;
authors.forename: Alex Lund
authors.initials: AL
authors.lastname: Laursen
authors.affiliation: Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Erikstrup
authors.affiliation: Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark;
authors.forename: Lars
authors.initials: L
authors.lastname: Østergaard
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.|Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark;|GloHAU, Center for Global Health, School of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Wejse
mesh_terms: D000328:Adult; D000368:Aged; D001364:Awareness; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D005260:Female; D006169:Guinea-Bissau; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D017211:Treatment Failure
keywords: Africa; CD4 cell count; Guinea-Bissau; HIV; treatment failure; viral load