E Khan1, I Azam, S Ahmed, R Hassan. 1. Departments of Pathology and Community Health Sciences, Aga Khan University Hospital, Karachi.
Abstract
OBJECTIVE: To compare the results of Dot Enzyme Immunoassay (EIA) and concomitantly performed blood culture for the diagnosis of typhoid fever. METHODS: The results of Dot Enzyme Immunoassay (EIA) of patients who also had blood cultures/bone marrow culture performed at the same time were analyzed. The period of study spans between April 1997-September 1997. RESULTS: A total of 1760 Dot Enzyme Immunoassays were performed from April 1997 to September 1997. Of these, only 128 (7.2%) cases had concomitantly performed blood/bone marrow cultures. Therefore, the study was narrowed down to these 128 cases. Sixty-nine cases were culture positive for S. typhi. Of these culture proven cases, IgM antibodies by Dot EIA were positive only in 49 (71%) cases while 20 (28.9%) of culture proven cases remained negative for IgM antibodies. CONCLUSION: Taking blood/bone marrow culture as gold standard, the sensitivity of Dot EIA was found to be 71% while specificity was found to be 43%. The predictive value of the positive test was found to be 59.7% and that of a negative test was found to be 56.5%.
OBJECTIVE: To compare the results of Dot Enzyme Immunoassay (EIA) and concomitantly performed blood culture for the diagnosis of typhoid fever. METHODS: The results of Dot Enzyme Immunoassay (EIA) of patients who also had blood cultures/bone marrow culture performed at the same time were analyzed. The period of study spans between April 1997-September 1997. RESULTS: A total of 1760 Dot Enzyme Immunoassays were performed from April 1997 to September 1997. Of these, only 128 (7.2%) cases had concomitantly performed blood/bone marrow cultures. Therefore, the study was narrowed down to these 128 cases. Sixty-nine cases were culture positive for S. typhi. Of these culture proven cases, IgM antibodies by Dot EIA were positive only in 49 (71%) cases while 20 (28.9%) of culture proven cases remained negative for IgM antibodies. CONCLUSION: Taking blood/bone marrow culture as gold standard, the sensitivity of Dot EIA was found to be 71% while specificity was found to be 43%. The predictive value of the positive test was found to be 59.7% and that of a negative test was found to be 56.5%.
Authors: Jessica Zuñiga; Luis Lillo; Junghee J Shin; Rajya L Machavarapu; Teresa Quiroga; Manuela Goycoolea; Betty Matsuhiro; L Aron-Hott; Henry P Godfrey; Felipe C Cabello Journal: J Clin Microbiol Date: 2005-09 Impact factor: 5.948