Evaluation of Typhidot (IgM) for Early Diagnosis of Typhoid Fever

Abstract

Typhoid fever still continues to be a major public health problem, particularly in many developing countries. A simple, reliable, affordable and rapid diagnostic test has been a long-felt need of the clinicians. We, therefore, prospectively evaluated the sensitivity and specificity of Typhidot (IgM), a serological test to identify IgM antibodies against Salmonella typhi. The study was carried out in the department of Microbiology, Mymensingh Medical College, Mymensingh between June, 2006 and July, 2007, on a total of 100 samples from clinically suspected patients to have typhoid fever. Blood culture as well as Typhidot test were performed for each of the cases. Out of 100 clinically diagnosed typhoid fever, 14 were blood culture positive for S. typhi and 73 were Typhidot (IgM) positive. Among 14 culture positive cases, 13 (92.85%) were Typhidot (IgM) positive. The test was also positive in 04 (20%) out of 20 febrile controls. None of the healthy controls was positive by Typhidot (IgM). The sensitivity, specificity, positive predictive value and negative predictive value of the test using blood culture as gold standard were 92.85%, 90.00%, 76.47% and 97.29% respectively for typhoid fever. Typhidot (IgM) test is rapid, easy to perform and reliable test for diagnosing typhoid fever, and useful for small, less equipped laboratories as well as for the laboratories with better facilities. Key words: Typhoid fever, Salmonella typhi, Typhidot (IgM) test doi: 10.3329/bjmm.v3i1.2964 Bangladesh J Med Microbiol 2009; 03 (01): 10-13