Comparison of multiple puncture liquid tuberculin test with Mantoux test.

Two studies were performed to compare the disposable liquid tuberculin PPD 'Imotest' with the Mantoux test. While there was a tester effect in the first study indicating the need for accurate application of the imotest, the results of the second study showed that the two tests were comparable in selecting truly positive and negative tuberculin reactors. Results were compared both by conventional methods and by a method new to tuberculin testing, the maximum likelihood technique. This method gives a more accurate estimate of false reaction rates. A significant difference was found between reading at 48 and 72 h for both tests. The acceptability and ease of reading of the imotest, with a tuberculin selectivity comparable to the Mantoux method, make it a suitable alternative tuberculin test, especially for screening large populations.