Suneel Prajapati1, Kriti Upadhyay1, Aparna Mukherjee2, S K Kabra2, Rakesh Lodha2, Varinder Singh3, Harleen M S Grewal4, Sarman Singh1. 1. a Division of Clinical Microbiology and Molecular Medicine , Department of Laboratory Medicine. 2. b Department of Paediatrics , All India Institute of Medical Sciences. 3. c Department of Paediatrics , Kalawati Saran Children Hospital , New Delhi , India. 4. d Section of Microbiology and Immunology, The Gade Institute, University of Bergen and Department of Microbiology , Haukeland University Hospital , Bergen , Norway.
Abstract
BACKGROUND: Drug susceptibility testing (DST) of Mycobacterium tuberculosis (Mtb) isolates is crucial for the effective treatment of tuberculosis. Data on DST patterns in Mtb isolates in childhood tuberculosis are scanty. AIMS: To determine drug resistance patterns in Mtb isolates from a paediatric TB cohort in North India. METHODS: 403 children aged 6 months to14 year with probable intrathoracic tuberculosis were enrolled prospectively. All were treatment-naïve. 802 ambulatory-induced sputa (IS) and 787 gastric aspirate (GA) samples were cultured in BACTEC-MGIT960 system, and DST of the Mtb isolates was undertaken using the automated BACTEC-MGIT960 SIRE kit. RESULTS: Of the 403 children, 147 (36.4%) were culture-confirmed: 132 (89.8%) isolates were Mtb and 15 (10.2%) non-tuberculous mycobacteria (NTM). Five Mtb isolates were contaminated and the remaining 127 were subjected to in-vitro drug susceptibility testing against streptomycin, isoniazid, rifampicin and ethambutol. Twenty-six (20.47%) isolates were resistant to one or more drugs, seven (5.5%) were resistant to rifampicin singly or in combination, and 11 (8.7%) were resistant to isoniazid singly or in combination. Mono-resistance to isoniazid, rifampicin, streptomycin and ethambutol was detected in four (3.1%), one (0.8%), four (3.1%) and two (1.6%), respectively. Five children (3.9%) had MDR-TB; 101 (79.9%) children had Mtb isolates which were sensitive to all four drugs. CONCLUSIONS: The rifampicin and isoniazid resistance rates were much higher than those in the adult TB population in India.
BACKGROUND: Drug susceptibility testing (DST) of Mycobacterium tuberculosis (Mtb) isolates is crucial for the effective treatment of tuberculosis. Data on DST patterns in Mtb isolates in childhood tuberculosis are scanty. AIMS: To determine drug resistance patterns in Mtb isolates from a paediatric TB cohort in North India. METHODS: 403 children aged 6 months to14 year with probable intrathoracic tuberculosis were enrolled prospectively. All were treatment-naïve. 802 ambulatory-induced sputa (IS) and 787 gastric aspirate (GA) samples were cultured in BACTEC-MGIT960 system, and DST of the Mtb isolates was undertaken using the automated BACTEC-MGIT960 SIRE kit. RESULTS: Of the 403 children, 147 (36.4%) were culture-confirmed: 132 (89.8%) isolates were Mtb and 15 (10.2%) non-tuberculous mycobacteria (NTM). Five Mtb isolates were contaminated and the remaining 127 were subjected to in-vitro drug susceptibility testing against streptomycin, isoniazid, rifampicin and ethambutol. Twenty-six (20.47%) isolates were resistant to one or more drugs, seven (5.5%) were resistant to rifampicin singly or in combination, and 11 (8.7%) were resistant to isoniazid singly or in combination. Mono-resistance to isoniazid, rifampicin, streptomycin and ethambutol was detected in four (3.1%), one (0.8%), four (3.1%) and two (1.6%), respectively. Five children (3.9%) had MDR-TB; 101 (79.9%) children had Mtb isolates which were sensitive to all four drugs. CONCLUSIONS: The rifampicin and isoniazid resistance rates were much higher than those in the adult TB population in India.