Evaluation of Xpert MTB/RIF assay in children with presumed pulmonary tuberculosis in Papua New Guinea.

BACKGROUND: The Gene Xpert MTB/ RIF assay (Xpert) is used for rapid, simultaneous detection of Mycobacterium tuberculosis (MTB) and rifampicin resistance. This study examined the accuracy of Xpert in children with suspected pulmonary tuberculosis (PTB). METHODS: Children admitted to Port Moresby General Hospital with suspected PTB were prospectively enrolled between September 2014 and March 2015. They were classified into probable, possible and TB-unlikely groups. Sputum or gastric aspirates were tested by Xpert and smear microscopy; mycobacterial culture was undertaken on a subset. Children were diagnosed with TB on the basis of standard criteria which were used as the primary reference standard. Xpert, smear for acid-fast bacilli (AFB) and the Edwards TB score were compared with the primary reference standard. RESULTS: A total of 93 children ≤14 years with suspected PTB were enrolled; 67 (72%) were classified as probable, 21 (22%) possible and 5 (5.4%) TB-unlikely. Eighty were treated for TB based on the primary reference standard. Xpert was positive in 26/93 (28%) MTB cases overall, including 22/67 (33%) with probable TB and 4/21 (19%) with possible TB. Three (13%) samples identified rifampicin resistance. Xpert confirmed more cases of TB than AFB smear (26 vs 13, p = 0.019). The sensitivity of Xpert, AFB smear and an Edwards TB score of ≥7 was 31% (25/80), 16% (13/80) and 90% (72/80), respectively, and the specificity was 92% (12/13), 100% (13/13) and 31% (4/13), respectively, when compared with the primary reference standard. CONCLUSION: Xpert sensitivity is sub-optimal and cannot be relied upon for diagnosing TB, although a positive result is confirmatory. A detailed history and examination, standardised clinical criteria, radiographs and available tests remain the most appropriate way of diagnosing TB in children in resource-limited countries. Xpert helps confirm PTB better than AFB smear, and identifies rifampicin resistance. Practical guidelines should be used to identify children who will benefit from an Xpert assay.

Holistic care of complicated tuberculosis in healthcare settings with limited resources.

In recent years, most of the focus on improving the quality of paediatric care in low-income countries has been on improving primary care using the Integrated Management of Childhood Illness, and improving triage and emergency treatment in hospitals aimed at reducing deaths in the first 24 hours. There has been little attention paid to improving the quality of care for children with chronic or complex diseases. Children with complicated forms of tuberculosis (TB), including central nervous system and chronic pulmonary TB, provide examples of acute and chronic multisystem paediatric illnesses that commonly present to district-level and second-level referral hospitals in low-income countries. The care of these children requires a holistic clinical and continuous quality improvement approach. This includes timely decisions on the commencement of treatment often when diagnoses are not certain, identification and management of acute respiratory, neurological and nutritional complications, identification and treatment of comorbidities, supportive care, systematic monitoring of treatment and progress, rehabilitation, psychological support, ensuring adherence, and safe transition to community care. New diagnostics and imaging can assist this, but meticulous attention to clinical detail at the bedside and having a clear plan for all aspects of care that is communicated well to staff and families are essential for good outcomes. The care is multidimensional: biomedical, rehabilitative, social and economic, and multidisciplinary: medical, nursing and allied health. In the era of the Sustainable Development Goals, approaches to these dimensions of healthcare are needed within the reach of the poorest people who access district hospitals in low-income countries.