Desafio diagnóstico da tuberculose intratorácica pediátrica em Belo Horizonte, Minas Gerais

Abstract

Introduction: Despite its ancient origins, tuberculosis (TB) remains a major public health problem. The pediatric population accounts for approximately 11% of the global burden of disease. Diagnosing TB in children is a challenge due to several factors related to the paucibacillary nature of the disease, the nonspecificity of the symptoms, the clinical similarity with other childhood diseases and the difficulty in collecting samples for diagnostic tests. Objectives: Study the clinical-epidemiological-laboratory profile of children diagnosed with intrathoracic TB in Belo Horizonte and analyze the performance of the tools used in its diagnosis. Methods: This is a retrospective cohort. Initially, a scope review was carried out, prepared according to the PRISMA® extension, addressing the missed opportunities in the prevention and diagnosis of childhood TB. As for the empirical study, were selected children aged 0 to 18 years with suspected intrathoracic TB or latent TB who were referred to specialized centers for childhood TB in Belo Horizonte, in the period from 2010 to 2020. The diagnosis of TB was determined in patients aged 0-10 years through the clinical-radiological-laboratory assessment according to the Ministry of Health, with a score of 30 points or higher, or microbiological confirmation. Patients were identified through active surveillance and data collection was performed by reviewing medical records, using a form with variables established for collection. The database and statistical analysis were performed using SPSS version 21.0. The performance of the diagnostic tests was evaluated using the Fagan nomogram, considering prevalence, specificity, sensitivity, accuracy, positive likelihood ratio and negative likelihood ratio. Georeferencing of patients with diagnosed TB was carried out in order to establish areas of greater vulnerability for Mycobacterium tuberculosis infection in Belo Horizonte and the metropolitan region. The study was approved by the Ethics Committee of the Institutions involved. Results: Were identified 133 patients, in which 65 were diagnosed with intrathoracic TB and in 68 patients TB disease was ruled out, among these, 49 were diagnosed with latent TB (LTBI). In the group of patients with TB disease, 75.4% reported previous contact with a TB carrier, with 91.8% defined as household contact. Only 12.3% of the children received previous treatment for LTBI. The microbiological diagnosis was obtained in 27.7% of the sample. A co-infection with TB and HIV was recorded in 10.4% of cases, with an unknown HIV status in 59.3% of the sample. The predominant radiological changes were mediastinal lymph node enlargement and parenchymal consolidation. When analyzing the performance of isolated diagnostic tools, greater accuracy (0.94) and positive likelihood ratio (10.6) were observed for changes in chest computed tomography. Chest radiography also performed well, with an accuracy of 0,82. The tuberculin skin test (TST) showed low accuracy (0.46) and there was no statistically significant difference (p=0,96) in relation to reading values between patients with TB disease and LTBI. Among the binary association of the score tools, the best accuracy was obtained in the combination of chest X-ray + symptomatology (0.85). Georeferencing identified the presence of cases of TB disease in all regions of the city and about 42% of patients lived in subnormal clusters. Conclusion: The initial imaging examination remains the chest X-ray, while the tomography should be reserved for cases of diagnostic doubt. The use of the tuberculin skin test is desired, but not essential. There is a need to invest in policies that address persistent gaps, such as contact tracing and LTBI treatment. To reduce the burden of disease in the pediatric population, it is essential to raise awareness that TB is endemic in Brazil and is present in all social strata. Due to its high prevalence, dynamism and mimicry, a high degree of suspicion of the disease by health professionals is essential.