Childhood tuberculosis in Qatar

Abstract

Childhood tuberculosis (TB) has been long neglected but has gained attention in recent years. In 2012, the World Health Organization annual report included an estimate for childhood TB for the first time, and in the following year, the TB Alliance received a grant from UNITAID (International Drug Purchase Facility) to develop pediatric TB formulations. Qatar is a low-incidence country. In this observational study, laboratory-confirmed cases of TB were analyzed from 2013 to 2015 and included patients aged ≤14 years. Microscopy and GeneXpert MTB/RIF (Cepheid, USA) and MGIT 960 (Becton, Dickinson and Company, USA) automated culture systems were used to confirm cases at the National TB Reference Laboratory, Doha, Qatar. A total of 24 positive cases were identified in this pediatric population, 21 with Mycobacterium tuberculosis complex (MTBC) and three with Mycobacterium other than tuberculosis (MOTT). Out of 21 MTBC cases, 19 were direct polymerase chain reaction (PCR) positive and two were smear and PCR negative but culture positive were later confirmed by PCR. Most of the positive specimens were extrapulmonary from pus and tissues biopsies. While six were from pulmonary, out of that, five were sputum and one was from gastric aspirates. Niacin Strip Test (Becton, Dickinson and Company, USA) was used to identify the Bacillus Calmette–Guérin (BCG) vaccine strains from MTBC infections, and seven patients were infected with BCG. Keeping in mind that there were 500–600 laboratory-confirmed cases of TB in adults, childhood tuberculosis is not a major problem in Qatar. Lack of sensitivity of niacin test due to identification various niacin accumulating BCG strains is documented worldwide, further testing with more stringent molecular methods will certainly increase the number of BCG isolates in this study population.

Keywords

• Childhood tuberculosis
• Qatar