Is tuberculosis difficult to diagnose in childhood and adolescence?

Objective: To determine the sensitivity of the scoring system proposed by the Brazilian National Ministry of Health in 2002 for the diagnosis of tuberculosis in children and adolescents suspected of having the disease. Methods: This was a retrospective study of 316 children and adolescents (0-14 years of age) diagnosed with pulmonary tuberculosis between 1997 and 2007 at the Brazilian Institute for Tuberculosis Research, located in the city of Salvador, Brazil. After reviewing the medical charts and chest X-rays of the patients, we calculated the tuberculosis scores. Results: The majority of the subjects (80.4%) had a history of close household contact with an AFB-positive adult within the last two years. The tuberculin test was negative in 11 subjects (3.5%). According to the scoring system, 251 (79.4%) were very likely to have tuberculosis (score, >= 40), 63 (19.9%) were moderately likely to have tuberculosis (score, 30-35), and 2 (0.7%) were unlikely to have tuberculosis (score, <= 25). When a cut-off score of 30 was used, the sensitivity of this scoring system was 99.3%. Conclusions: In our sample, the sensitivity of this scoring system was high when the selected cut-off score was employed. If a cut-off score of 40 had been used, 20% of the subjects would not have been treated. Therefore, scores between 30 and 35 are critical for diagnostic confirmation. Judicious clinical evaluation should prevail in the decision of treating these patients. When the cut-off score of 30 is used, 30% of individuals with other pathologies will be treated for tuberculosis. This highlights the need for improved diagnostic methods for tuberculosis.