Outcome of culture-confirmed isoniazid-resistant rifampicin-susceptible tuberculosis in children

SETTING: Isoniazid-resistant rifampicin-susceptible (H^RR^S) tuberculosis (TB) is the most prevalent form of drug-resistant TB globally, and may be a risk factor for poor outcomes, but has been poorly described in children.

OBJECTIVE: To characterise the clinical presentation, treatment, and clinical and microbiological outcomes among children with culture-confirmed H^RR^S TB.

DESIGN: Retrospective hospital-based cohort study.

RESULTS: Of the 72 children included in the study, the median age was 50.1 months (IQR 21.5–102.5); 42% were male. Forty-four (51%) had a potential source case; only 13 were confirmed H^RR^S TB. Of 66 tested, 12 (17%) were human immunodeficiency virus (HIV) infected, and 36 (60%) of the 60 with pulmonary TB (PTB) had severe disease. Seventy children had treatment data; the median total duration of treatment was 11.3 months (IQR 9–12.3); 25 (36%) initiated treatment with a three-drug intensive phase; 52 (74%) received a fluoroquinolone. Of 63 children with known outcomes, 55 (88%) had a favourable outcome, 1 died and 3 had treatment failure. Ten had positive follow-up cultures at 2 months after starting treatment. Older age (P = 0.008), previous anti-tuberculosis treatment (P = 0.023) and severe PTB (P = 0.018) were associated with failure to culture-convert at 2 months.

CONCLUSIONS: Although overall outcomes were good, prolonged culture positivity and cases of treatment failure emphasise the need for additional attention to the management of children with H^RR^S TB.