Tuberculosis (TB) accounts for 1.7 million deaths, according to the recent WHO report. India alone accounts for one fifth (21%) of all the TB cases globally. Mycobacterial pathogens are classified into Typical Mycobacteria and Atypical Mycobacteria. Studies have shown that adolescents are a vulnerable age group having higher chance of getting pulmonary TB infection and disease compared to younger children and adults. This age group is a target group for vaccination.
To estimate the proportion of definite TB and probable TB in 12-18 year old adolescents.
To estimate the rate of Nontuberculous Mycobacteria (NTM) in the same group.
The present study is part of a prospective, observational two year cohort study conducted among school/ college going adolescents, 12-18 years in Palamaner taluk, South India during February 2007 to July 2010. A total of 609 participants attended the diagnostic ward with any of the criteria for referral. The sputum specimens were examined by concentrated AFB smear microscopy and processed for culture. Written informed assent from the subjects and consent from the parents or guardians was obtained at the time of enrollment of the participant before the start of the procedures.
During the 2 years follow-up of 6643 participants, 609 participants attended the diagnostic ward (DGW) for Tuberculosis testing. Among all these participants, 310 (50.9%) were males and 299 (49.1%) participants were females. 443 (72.9%) participants were referred to DGW based on TST positivity (greater than or equal to 10 mm). A total number of 7 (1.15 %) participants were diagnosed as definite TB, 3 (0.50 %) participants were diagnosed as probable TB. The proportion of 19.05% participants had NTM positive sputum samples. Participants having cough for equal to greater than 2 weeks were, 19 times more likely to become positive for M.tb growth of sputum sample (O.R = 18.60; 95% C.I = 4.02 - 86.05). There was 2 times greater chance of isolating NTM from participants who belongs to Dalit/ Harijan's community.
The proportion of the cases detected in our study was less compared to the estimation by Revised National Tuberculosis Control Programme (RNTCP), in 2007 and what other studies had shown. Most of the participants those referred to diagnostic ward did not show up for TB tests. We consider that, the NTM species isolated in our study are either by chance or by the contamination of sputum samples by environmental Mycobacteria. These isolates therefore had no clinical significance.
Further studies need to be conducted to ascertain the actual burden of TB disease among all the adolescent age groups including people who don't go to schools. There must be further studies to find out the clinical significance of NTM among the adolescent age groups.||eng