Risk of developing active TB in children with latent TB infection

Abstract

Introduction or background: Effective treatment of latent tuberculosis infection (LTBI) is an important component in the fight against tuberculosis in children.

Objectives: The aim of this study is determine the effectiveness of preventive treatment of latent tuberculosis infection in children.

Materials and Methods: 209 children from 3 to 14 years old with positive results of tuberculin skin test were examined during 2013-2014 at children's phthisiopulmonology department (St.-Petersburg Institute of Phthisiopulmonology). Diagnostic complex included: QuantiFERON®-TB Gold (QFT), Diaskintest ® ( DST ) and computed tomography (CT). After examination in 80 children LTBI was diagnosed, in 54 children - tuberculosis, 75 children were confirmed as healthy . Patients with LTBI (80) were followed for 12 months. All LTBI children were divided in two groups: I group – 32 children (37.3%) who received preventive therapy (two anti-tuberculosis drugs for 3 months: isoniazid at dose of 10 mg / kg and pyrazinamide at dose of 25 mg / kg). II group – 48 children (62.7%) who did not get preventive therapy because their parents refused.

Results: After control examination in 12 month 52 children (65%) developed tuberculosis and 28 children (35%) have the same status – LTBI. When comparing the incidence of active tuberculosis in children found that those who received preventive therapy, became ill in 59.4% (19) of cases, and children who didn't receive– in 68.8% (33), which is not statistically significant (p> 0,1).

Conclusions: Risk of developing TB in children with LTBI is quite high (65%). Carrying out preventive therapy for children with LTBI for 3 months has not significantly reduced the number of cases of tuberculosis.