**4. Unrecognised MDR TB populations**

### **4.1. Pediatric MDR TB**

Pediatric TB diagnosis has also been largely based on clinical criteria due to the pauci bacillary nature of their disease [3, 34-36]. In the cases of TB HIV coinfection, the diagnosis of TB disease is usually more difficult because the symptom specificity is reduced due to similarity with chronic HIV-related symptoms, and chest radiograph interpretation is complicated by HIVrelated comorbidity and atypical disease presentation. In this case, diagnosis involves linking the child with an adult with confirmed pulmonary TB [37]. However, older children producing sputum can have bacteriological confirmation and where facilities are accessible DST is performed [8]. To date, there is still widespread under-diagnosis of MDR TB in younger children. Children are less likely than adults to acquire MDR TB during treatment due to the lower bacillary load and less-frequent cavity formation [38]. Acquisition of strains of MDR TB through primary transmission has been shown to be same for children as for adults [39].

The implication of this is that with increasing adult MDR TB in populations, there would be increasing incidences of pediatric MDR TB. Once a diagnosis of TB is made, MDR TB should be carefully considered by review of household source cases for drug-resistant disease [40]. Child contacts of adults with coinfection of TB HIV should particularly be screened for MDR TB. The recent efforts to improve on MDR diagnostic tests using non-respiratory specimens should be harnessed for the pediatric age populations so that rapid diagnostic tests become the first-line diagnostic tool for pediatric MDR TB. Outcomes of MDR TB in children depend on prompt diagnosis and initiation of appropriate therapy for drug-resistant strain [41].
