Accuracy of Xpert Ultra for the diagnosis of paediatric tuberculosis in a low TB burden country: a prospective multicentre study.

INTRODUCTION: Childhood pulmonary tuberculosis (TB) remains a diagnostic challenge. This study aimed to evaluate the performance of Xpert Ultra for the diagnosis of pulmonary TB in children in a low TB prevalence setting. METHODS: Prospective, multicentre, diagnostic accuracy study. Children with clinical or radiological suspicion of pulmonary TB were recruited at 11 paediatric units in Spain. Up to three gastric or sputum specimens were taken on 3 consecutive days, and analysed by Xpert MTB/RIF, Xpert Ultra and culture in parallel. RESULTS: 86 children were included (median age 4.9 years, IQR 2.0-10.0; 51.2% male). The final diagnosis was pulmonary TB in 75 patients (87.2%); 33 (44.0%) were microbiologically confirmed. A total of 219 specimens, comprising gastric aspirates (n=194; 88.6%) and sputum specimens (n=25; 11.4%), were analysed. Using culture as reference standard and comparing individual specimens, the sensitivity was 37.8% (14/37) for Xpert MTB/RIF and 81.1% (30/37) for Xpert Ultra (p<0.001); specificity was 98.4% (179/182) and 93.4% (170/182), respectively (p=0.02). In the per-patient analysis, considering positive results on any specimen, the sensitivity was 42.9% (9/21) for Xpert MTB/RIF and 81.0% for Xpert Ultra (17/21, p=0.01); specificity was 96.9% (63/65) and 87.7% (57/65, p=0.07), respectively. CONCLUSIONS: In children with pulmonary TB in a low burden setting, Xpert Ultra has significantly higher sensitivity than the previous generation of Xpert assay and only marginally lower specificity. Therefore, in children undergoing evaluation for suspected pulmonary TB, Xpert Ultra should be used in preference to Xpert MTB/RIF whenever possible.

Development and Evaluation of an NTM-IGRA to Guide Pediatric Lymphadenitis Diagnosis.

BACKGROUND: Diagnosis of nontuberculous mycobacteria (NTM) infections remains a challenge. In this study, we describe the evaluation of an immunological NTM-interferon (IFN)-γ release assay (IGRA) that we developed using glycopeptidolipids (GPLs) as NTM-specific antigens. METHODS: We tested the NTM-IGRA in 99 samples from pediatric patients. Seventy-five were patients with lymphadenitis: 25 were NTM confirmed, 45 were of unknown etiology but compatible with mycobacterial infection and 5 had lymphadenitis caused by an etiologic agent other than NTM. The remaining 24 samples were from control individuals without lymphadenitis (latently infected with M. tuberculosis , uninfected controls and active tuberculosis patients). Peripheral blood mononuclear cells were stimulated overnight with GPLs. Detection of IFN-γ producing cells was evaluated by enzyme-linked immunospot assay. RESULTS: NTM culture-confirmed lymphadenitis patient samples had a significantly higher response to GPLs than the patients with lymphadenitis of unknown etiology but compatible with mycobacterial infection ( P < 0.001) and lymphadenitis not caused by NTM ( P < 0.01). We analyzed the response against GPLs in samples from unknown etiology lymphadenitis but compatible with mycobacterial infection cases according to the tuberculin skin test (TST) response, and although not statistically significant, those with a TST ≥5 mm had a higher response to GPLs when compared with the TST <5 mm group. CONCLUSIONS: Stimulation with GPLs yielded promising results in detecting NTM infection in pediatric patients with lymphadenitis. Our results indicate that the test could be useful to guide the diagnosis of pediatric lymphadenitis. This new NTM-IGRA could improve the clinical handling of NTM-infected patients and avoid unnecessary misdiagnosis and treatments.

Clinical Presentations and Outcomes Related to Tuberculosis in Children Younger Than 2 Years of Age in Catalonia.

Introduction: Children younger than 2 years have an increased risk of complications associated with tuberculosis (TB) due to the immaturity of the innate and adaptive immune response. We aimed to identify TB clinical presentations and outcomes as well as risk factors for complications in this age group. Materials and Methods: Multicenter, retrospective, cross-sectional study of TB cases in children aged <2 years in Catalonia (2005-2013). Epidemiological and clinical data were collected from the hospital medical records. TB complications, sequelae included, were defined as any tissue damage generating functional or anatomical impairment after being diagnosed or after TB treatment being completed. Statistical analyses were based on bivariate chi-square and multivariate logistic regression, and it was carried out with Stata® version 13.1. Odds ratios (OR) and its 95% confidence intervals were calculated (CI). Results: A total of 134 patients were included, 50.7% were male, the median [IQR] age was 13[8-18] months, and 18.7% (25/134) showed TB-associated complications. Pulmonary TB was diagnosed in 94.0% (126/134) of children, and the most common complications were lobar collapse (6/126). TB meningitis was diagnosed in 14/134 (10.4%), and hydrocephalus and mental impairment occurred in 1 and 2 patients, respectively. Two patients with spinal TB developed vertebral destruction and paraplegia, respectively. Only one of the patients died. At multivariate level, tachypnea (OR = 4.24; 95% CI 1.17-15.35) and meningeal (OR = 52.21; 95% CI 10.05-271.2) or combined/extrapulmonary forms (OR = 11.3; 95% CI 2.85-45.1) were associated with the development of TB complications. Discussion: TB complications are common in children under 2 years old. Extrapulmonary TB forms in this pediatric age remain a challenge and require prompt diagnosis and treatment in order to prevent them. The presence of tachypnea at the time of TB diagnosis is an independent associated factor to the development of TB complications in infants. This clinical sign should be closely monitored in patients in this age group. It is necessary to perform further studies in this age group in a prospective design in order to understand whether there are other factors associated to TB complications.

Pregnancy as an opportunity to diagnose human-immunodeficiency virus immigrant women in Catalonia. / El embarazo como una oportunidad de diagnóstico del virus de la inmunodeficiencia humana en mujeres inmigrantes en Catalunya.

INTRODUCTION: Mother-to-child transmission (MTCT) is relevant in the global epidemiology of human-immunodeficiency virus (HIV), as it represents the main route of infection in children. The study objectives were to determine the rate of HIV-MTCT and its epidemiological trend between the Spanish-born and immigrant population in Catalonia in the period 2000-2014. METHODS: A prospective observational study of mother-child pairs exposed to HIV, treated in 12 hospitals in Catalonia in the period 2000-2014. HIV-MTCT rate was estimated using a Bayesian logistic regression model. R and WinBUGS statistical software were used. RESULTS: The analysis included 909 pregnant women, 1,009 pregnancies, and 1,032 children. Data on maternal origin was obtained in 79.4% of women, of whom 32.7% were immigrants, with 53.0% of these from sub-Saharan Africa. The overall HIV-MTCT rate was 1.4% (14/1,023; 95% CI; 0.8-2.3). The risk of MTCT-HIV was 10-fold lower in women with good virological control (P=.01), which was achieved by two-thirds of them. The proportion of immigrants was significantly higher in the period 2008-2014 (P<.0001), for the HIV-diagnosis (P<.0001), and antiretroviral administration (P=.02) during pregnancy, and for undetectable viral load next to delivery (P<.001). There were no differences in the rate of MTCT-HIV among Spanish-born and immigrant women (P=.6). CONCLUSIONS: There is a gradual increase in HIV pregnant immigrants in Catalonia. Although most immigrant women were diagnosed during pregnancy, the rate of MTCT-HIV was no different from the Spanish-born women.