Diagnosis of pulmonary tuberculosis by score system in children and adolescents: a trial in a reference center in Bahia, Brazil

ABSTRACT

Since 2002, the Brazilian Ministry of Health has recommended a score system for tuberculosis diagnosis of children and adolescents that does not need bacteriological positivity, because most cases in this age group have few bacteria. An observational, transversal study was carried out at the outpatient health care service of the reference medical service in Salvador, Bahia, including 164 patients with pulmonary tuberculosis, with ages ranging between 1 and 15 years of age, who were treated from 1990 to 2001. The gold standard used to establish the diagnosis was clinical, radiological, epidemiological and based on follow-up data. The score system for diagnosis purposes was tested retrospectively. The median age and the average age of the 164 patients were 6 and 6.62 years (SD ± 4.33), respectively. About 65 percent of the sample reported a history of close contact with a tuberculous adult. The BCG vaccine coverage was 70.7 percent (116/164). It was found that 26 percent (43/164) of the patients had severe malnutrition. Out of this group, 26/43 (60.47 percent) were < 5mm reactive to the tuberculin test. On the other hand, out of the 91 patients with tuberculin test < 5mm, 29 percent (26/ 91) had severe malnutrition. The use of the score gave the following distribution a) TB very likely in 81.7 percent (134/164) of the patients; b) possible TB in 15.9 percent (26/164) and TB unlikely in 2.4 percent (4/164). Among patients who had been vaccinated more than 2 years before, there was a 9 times higher risk of finding a tuberculin test above 10 mm in individuals with probable TB in comparison with the patients with possible or unlikely TB.