Intensified specimen collection to improve tuberculosis diagnosis in children from Rural South Africa, an observational study
1 Division of Infectious Diseases & International Health, University of Virginia, PO Box 801337, Charlottesville, VA 22908-1337, USA
2 University of KwaZulu-Natal, Durban, KZN, South Africa
3 Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
4 Yale University School of Medicine, New Haven, CT, USA
5 Philanjalo, Tugela Ferry, KZN, South Africa
6 Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
BMC Infectious Diseases 2014, 14:11 doi:10.1186/1471-2334-14-11Published: 9 January 2014
In drug-resistant TB settings, specimen collection is critical for drug-susceptibility testing (DST). This observational study included multiple specimen types collected from pediatric TB suspects with the aim to determine diagnostic yield and inform clinical practice in children with drug-resistant and drug-susceptible TB.
From 03/2009-07/2010, TB suspects aged ≥6 months and ≤12 years were recruited among outpatient and inpatient settings. Subjects were new TB suspects or had persistent symptoms despite ≥2 months of TB treatment. The protocol included collection of a single blood and urine specimen, a single sputum induction and, if inpatients and <5 years of age, collection of 3 gastric aspirates (GA). Samples were cultured on solid and/or liquid media. DST was by 1% proportion method.
Among 118 children with possible, probable or confirmed TB, the mean age was 4.9 years [SD 3.2] and 64 (62%) of those tested were HIV-positive. Eight (7%) subjects were culture-positive from at least one specimen; yield did not differ by HIV status or TB treatment history. Among those with positive cultures, 7/8 (88%) were from induced sputum, 5/6 (83%) from GA, 3/8 (38%) from blood, and 3/7 (43%) from urine. In subjects with both induced sputum and GA collection, sputum provided one additional case compared to GA. Multidrug resistant (MDR)-TB was detected by urine culture alone in one child >5 years old. Pan-resistant extensively drug resistant (XDR)-TB was identified by cultures from all sites in one subject.
TB was cultured from HIV-positive and -negative children, and allowed for identification of MDR and XDR-TB cases. Urine and induced sputum each provided an additional TB diagnosis and, when compared to GA, may be considered a less invasive, same-day method of specimen collection for childhood TB suspects. This study illustrates the continued challenges and limitations of available strategies for pediatric TB diagnostics.