String Test: A New Tool for Tuberculosis Diagnosis and Drug‑Resistance Detection in Children

SANJURJO M; PALOMINO JC; IMPERIALE B; TARTARA S; MORCILLO N; NIEVES C; DI GIULIO B; MARTIN A

Vicente Lopez

Jornada; Jornadas de Actualización en Alteraciones Respiratorias asociadas a la Obesidad Y Presentación Actividad Científica del Hospital Cetrángolo; 2018

Background: There is a critical need to improve the diagnostic accuracy of tuberculosis (TB) in children. Several techniques havebeen developed to improve the quality of sputum samples; however, these procedures are very unpleasant and invasive and requirehospitalization and trained personnel. This study aims to explore the potential use of a new and noninvasive tool, ?string test,? for TBdiagnosis in children and in adults not able to render sputum samples and at risk of developing multidrug‑resistant TB (MDR‑TB).Methods: Children with clinical suspicion of TB attending the pediatric consultation at the Cetrangolo or Cordero Hospitals and adultssuspected of MDR‑TB and unable to produce sputum attending the Infectious Disease Unit of Cetrangolo Hospital were included in thisstudy. Subjects and Methods: The ?string test? is a string that is swallowed by the patients and exposed to gastrointestinal secretions thatwere late analyzed for TB diagnosis and drug‑resistance detection by GenoType MTBDRplus. MedCalc software was used to performstatistical analysis. Results: This technique could be applied on 62.1% of selected children. About 11 (30.6%) children were diagnosedas TB cases, 8 (22.2%) from gastric aspirate and using the ?string test.? Six out of 19 adults were also diagnosed. Genotype directly onthe string specimen detected two MDR‑TB in adults and two isoniazid‑resistant cases before obtaining the isolate. Conclusion: This testwas safe, cheap, and easily implemented without requiring hospitalization. This research could represent a significant step forward todiagnose and rapidly detect drug‑resistant TB in children.