First-line treatment failure category | Number of patients with failure (%) | Number of patients with viral load ≥1000 copies/mL | PPV (%) to detect treatment failure (95% CI) |
---|---|---|---|
WHO immunological failure | 376 (100.0) | 226/376 (60.0) | 60.1 (57.1 to 69.3) |
WHO immunological failure subclass | |||
CD4 count declined to pre-ART baseline value | 159 (42.3) | 90 (38.1) | 56.7 (47.8 to 69.0) |
CD4 count declined to <50% of peak while receiving ART | 114 (30.3) | 70 (33.1) | 61.4 (58.1 to 68.2) |
CD4 <100 cell/mm3 after 1 year of ART | 103 (27.4) | 66 (28.0) | 64.1 (57.2 to 69.8) |
Treatment failure is defined by immunological, clinical and virological criteria.3 Immunological criteria are CD4 cell count: returns to, or drops below, baseline CD4 cell count; falls to <50% of the maximum CD4 cell count while receiving ART; or falls persistently <100 cells/mm3 after 1 year of ART. Virological criterion is plasma viral load ≥1000 copies/mL based on two consecutive viral load measurements after 3 months with adherence support.3 Clinical criterion is a new or recurrent clinical event indicating advanced or severe immunodeficiency (WHO clinical stage 3 and 4 clinical condition with the exception of tuberculosis) after 6 months of effective treatment.3