Tuberculosis retreatment category predicts resistance in hospitalized retreatment patients in a high HIV prevalence area

Rates of multidrug-resistant tuberculosis (MDR-TB) are currently as high as 7.7% in retreatment cases in KwaZulu-Natal, South Africa. MDR-TB prevalence is known to be high in patients categorized as treatment failures. Recent reports have questioned the effectiveness of the World Health Organization (WHO) Category II regimen in retreatment TB cases.To determine whether treatment category predicts susceptibility patterns and outcomes in a hospitalized population of retreatment TB cases.Retrospective cohort of 197 pulmonary retreatment cases.Retreatment cases treated with the standard retreatment regimen had a high in-hospital mortality (19.8%), or poor outcome (26.4%) and a high rate of MDR-TB (16.2%). The 'treatment failure' category predicted resistance, with 57.1% of patients exhibiting any resistance compared to other treatment categories (P = 0.02); 53.8% of patients with any resistance experienced poor outcomes, compared to 16.6% of pan-susceptible cases (P = 0.02). There was a trend towards poor outcome in the treatment failure category (42.9%, P = 0.13).The retreatment category 'treatment failure' is associated with a high prevalence of resistance in an area of high human immunodeficiency virus (HIV) prevalence. The 'treatment failure' category should be used to identify patients who may benefit from alternative regimens using directed, intensified therapy or second-line agents instead of the current standard retreatment regimen.