Extraspinal osteoarticular multidrug-resistant tuberculosis in children: A case series.

BACKGROUND: South Africa (SA) is known to have a high disease burden of tuberculosis (TB). Extraspinal osteoarticular multidrug-resistant tuberculosis (ESOA MDR-TB) in children has only been described in a few case reports worldwide. OBJECTIVES: To describe the epidemiology and highlight the potential problem of ESOA MDR-TB infections as seen in children from a single academic hospital in SA. METHODS: A retrospective record review was performed on all children diagnosed with ESOA TB infection at Chris Hani Baragwanath Academic Hospital, Johannesburg, between 1 January 2006 and 31 December 2015. All patients with a positive TB culture (fluid or tissue) from the surgical site of biopsy (bone or joint) and who were hospitalised were included. Organism culture and drug sensitivity testing were performed. RESULTS: Overall 19 cases of ESOA TB were identified. Areas involved included the shoulder (2 cases), elbow (2 cases), hip (7 cases), knee (4 cases), ankle (3 cases) and humerus (1 case). The mean age of the population was 7.7 (range 2.0 - 14.0) years. The mean white cell count was 11.3 (range 5 - 28.9) × 109/L, the mean C-reactive protein level 53.8 (range 1.0 - 364.0) mg/L and the mean erythrocyte sedimentation rate 35.5 (range 4.0 - 85.0) mm/h. Two cases (10.5%) were MDR, and a further case (5.3%) was resistant to isoniazid only. Four of 12 patients tested positive for HIV. One of the HIV-positive patients was isoniazid resistant. The two positive ESOA MDR-TB cases are discussed in detail. CONCLUSIONS: These findings indicate that ESOA MDR-TB is a reality in this paediatric population (10.5%) and a high index of suspicion should be maintained, especially when cultures are negative in children with signs and symptoms of ESOA TB. The effect of HIV infection on the incidence of ESOA MDR-TB requires further study.

Molecular typing of drug-susceptible and -resistant Mycobacterium tuberculosis in Johannesburg, South Africa.

SETTING: Knowledge about spoligotyping families of drug-susceptible and drug-resistant Mycobacterium tuberculosis circulating in the Johannesburg area, South Africa, is lacking. OBJECTIVE: To determine the genetic diversity of M. tuberculosis isolates circulating in the Johannesburg area and to compare the results with both national and international databanks. DESIGN: Five hundred cultured M. tuberculosis isolates from within the greater Johannesburg metropolitan area collected from January 2009 to December 2010 were obtained from the National Health Laboratory Services (NHLS) Mycobacteriology Referral Laboratory, Johannesburg, in MGIT vials. The isolates were specimens from individuals with tuberculosis (TB) symptoms and known TB patients submitted to the NHLS for routine mycobacterial culture and drug susceptibility testing. The isolates were genotyped using spoligotyping. RESULTS: Spoligotyping generated 62 shared types, with 92% (458/500) of the sample size matching pre-existing shared types. Of the 62 shared types, eight families were predominant (clustering from 16 to 132), representing 64% (340/500) of the sample. The Beijing family (135/500) predominated (P < 0.001). CONCLUSION: TB incidence in Johannesburg does not appear to be due to clonality, but is rather due to diverse circulating strains, namely the Beijing family, followed by the S, Latin American-Mediterranean and T families.

Diagnostic accuracy and effectiveness of the Xpert MTB/RIF assay for the diagnosis of HIV-associated lymph node tuberculosis.

Xpert MTB/RIF (Xpert) is recommended for human immunodeficiency virus (HIV)-associated pulmonary tuberculosis but not extrapulmonary tuberculosis. We assessed the performance of Xpert for HIV-associated lymph node tuberculosis (LNTB), the most common type of extrapulmonary tuberculosis. Among HIV-infected adults suspected of LNTB presenting for fine needle aspirate (FNA) at a South African hospital, we assessed the diagnostic accuracy of Xpert using either FNA culture or a composite of microscopy, culture, and cytology as the reference standard, and evaluated the impact of different diagnostics on patient management. Among 344 adults with valid FNA culture and Xpert results, 84 (24 %) were positive on microscopy, 149 (43 %) on culture, 152 (53 %) on Xpert, and 181 (57 %) had a cytology result suggestive of tuberculosis. Using liquid culture as the reference standard, the specificity of a single Xpert was suboptimal (88.2 %) but the sensitivity was high [93.3 %, 95 % confidence interval (CI) 87.6-96.6] and increased with decreasing CD4 count (from 87.0 % for CD4 >250 to 98.6 % for CD4 <100 cells/mm(3)). Using a composite reference standard reduced the sensitivity to 79.2 % but increased the specificity to 98.6 %. All Xpert-positive patients initiated treatment within one day, compared to 70 % of culture-positive but Xpert-negative and 13 % of culture- and Xpert-negative but cytology-positive patients. Xpert is accurate and effective and could be endorsed as the initial diagnostic for HIV-associated LNTB.