Primary tuberculosis in children. 2. Correlation of susceptibility patterns of M. tuberculosis isolated from children with those isolated from source cases as an index of drug-resistant infection in a community

Identifying the sources of tuberculosis in young children: a multistate investigation

To better understand the molecular epidemiology of tuberculosis (TB) transmission for culture-confirmed patients <5 years of age, data were analyzed from a population-based study conducted in seven U.S. sites from 1996 to 2000. Mycobacterium tuberculosis isolates were genotyped with IS6110-based restriction fragment length polymorphism analysis and spoligotyping. Case-patient data were obtained from the Centers for Disease Control and Prevention s national tuberculosis registry and health department records. Routine public health investigations conducted by local health departments identified suspected source patients for 57 (51%) of 111 culture-confirmed patients <5 years of age. For 8 (15%) of 52 culture-confirmed patients <5 years of age and their suspected source patients with complete genotyping results, genotypes suggested infection with different TB strains. Potential differences between sources for patients <5 years of age and source patients that transmitted TB to adolescent and adult patients were identified.

DRUG RESISTANT TUBERCULOSIS - THE EMERGING SCENARIO

During the period April 1992 to September 1994 a total of 2288 patients of pulmonary tuberculosis were treated at our centre. M. tuberculosis could be isolated from the sputa of 1037 patients (45.3%). All the isolates were subjected to indirect susceptibility testing using drug incorporated Lowenstein-Jensen medium slants. A total of 142 (13.7%) patients showed drug resistance. Single drug resistance was observed in 86 (8.3%) patients whereas resistance to two or more drugs was observed in 56 (5.4%) patients. Patients showing initial drug resistance were more in number (83 cases) than those showing acquired drug resistance (59 cases). Resistance to streptomycin was commonest (8.3% of isolates) followed by isoniazid (5.7%) and rifampicin (5.0%). Multiple drug resistance was mostly acquired (71.4% of drug-resistant isolates).