Diagnostic value of dot-enzyme-immunoassay test to detect outer membrane protein antigen in sera of patients with typhoid fever.

Typhoid fever is still an important public health problem in many developing countries especially in tropical parts of the world, as in Indonesia. This problem opens the way for a further study with the aim of finding an alternative serological test with a high degree of reliability for the detection of typhoid fever. Given the above mentioned purpose, a study on the reliability of a laboratory test, the dot-enzyme-immunoassay outer membrane protein (DOT-EIA-OMP) was conducted comprising sera from 207 subjects (44 adult typhoid patients, 43 adult nontyphoid patients and sera from 120 adult healthy individuals serving as controls. The result of the study revealed that the diagnostic sensitivity of the DOT-EIA-OMP test for the detection of typhoid fever can be classified as high (93.16%), the specificity as moderate (76.74%), the efficiency (accuracy), positive predictive value and negative predictive value as high (85.06%, 80.39% and 91.66% respectively). The within run and between days reproducibility of this test was very high (CV=0%). Analysis of data obtained indicated that the DOT-EIA-OMP test was a reliable screening test for the establishment of the diagnosis of typhoid fever in health centers with simple laboratory facilities. The application of this test has to be more contemplated in countries where the cost of laboratory test is a problem.