Mantoux test tuberculin reaction in Nigerians

Thirty-seven Nigerian tuberculosis patients and 75 control volunteers were Mantoux-tested with 1 or 5 or 10 tuberculin units of Tween-80 stabilised purified protein derivative (P.P.D.) in order to relate tuberculosis infection to skin reactivity. Serum transferrin and albumin levels determined by radial immunodiffusion technique showed some overlap but test patients tended to have lower values than controls. Skin reaction was not significantly affected by age which varied from 6 to 55 years or the extend of tuberculosis treatment at Mantoux testing. For comparable P.P.D. doses Mantoux readings greater than 9.9mm showed 86.5% sensitivity for tuberculosis but presented low (28%) specificity in contrast to readings greater than 15mm with specificity of 74.7%. Significantly higher proportion of test patients than controls showed skin reaction greater than 9.9mm (p < 0.05) whereas the difference was insignificant at 9mm. With improving nutrition there is need for a large-scale reappraisal of the value of intradermal tuberculin test in diagnosing active tuberculosis in Nigerian reactors.