Lack of awareness of treatment failure among HIV‐1‐infected patients in Guinea‐Bissau – a retrospective cohort study

Introduction 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.