Radiographic abnormalities in tuberculosis and risk of coexisting human immunodeficiency virus infection. Results from Dar-es-Salaam, Tanzania, and scoring system.

Abstract

First, we evaluated the age profile and chest radiographic abnormalities in 146 patients from Dar-es-Salaam, Tanzania, with new-onset intrathoracic tuberculosis (pulmonary, pleural, or hilar/mediastinal adenopathy), to identify features that were associated with human immunodeficiency virus (HIV) seropositivity or seronegativity; then, we combined these data with those from a companion investigation in Burundi to develop a simple scoring system to predict HIV serologic status. Using agreed-upon criteria and simplified reporting forms, initial chest radiographs were reviewed by three readers, first independently and then at a consensus conference. Of the 146 patients, 80 (55%) were HIV seropositive and 66 were seronegative. More seropositive than seronegative subjects were 31 to 40 yr old (p = 0.03). Because the radiographic characteristics of the two serologic groups were similar in Tanzania and Burundi, we combined the data for stepwise logistic regression that revealed four highly significant variables: age, small lesions, location, and lymphadenopathy. From these, we obtained an equation to calculate the probability that a given tuberculosis patients was HIV seropositive and then we derived a scoring system that in its simplest form (threshold) predicted serologic status correctly in 68.1% of patients; a graded scale was even more accurate in the high (89.1%) and low (82.6%) ranges. This scoring system should be useful when serologic testing is unavailable or refused.