Ralte Lalremruata1, Sanjim Chadha2, Preena Bhalla3. 1. Student, Department of Microbiology, Maulana Azad Medical College , New Delhi, India . 2. Senior Resident, Department of Microbiology Maulana Azad Medical College , New Delhi, India . 3. Director Professor, Department of Microbiology, Maulana Azad Medical College , New Delhi, India .
Abstract
INTRODUCTION: Although typhoid fever is confirmed by culture of Salmonella Typhi, Widal test is widely used in India but little information exists about its reliability. MATERIALS AND METHODS: We examined the performance of Widal test in our hospital for diagnosis of typhoid fever in children. Hundred consecutive pediatric in-patients for whom, the Widal test was requested were grouped into four categories: widal positive and clinically consistent with typhoid fever (Group 1; n=42), widal negative but clinically consistent (Group 2, n=12), widal positive but not clinically consistent (Group 3, n=12) and widal negative and also not clinically consistent (Group 4, n=34). The results were analyzed by the test performance criteria, namely, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) using culture-confirmed typhoid fever cases as the "true positives". RESULTS: We found that 7/100 patients had culture-proven typhoid fever. Using a cut off ≥ 50 for O agglutinins or ≥100 for H agglutinins, the Widal test gave a sensitivity of 71.43%, specificity of 47.31%, and a positive predictive value of 09.25% and a negative predictive value of 95.65%. CONCLUSION: The Widal test is an easy, inexpensive and relatively non-invasive but is not reliable in our set up because of a low PPV. There is a need for a more efficient rapid diagnostic test for typhoid fever.
INTRODUCTION: Although typhoid fever is confirmed by culture of Salmonella Typhi, Widal test is widely used in India but little information exists about its reliability. MATERIALS AND METHODS: We examined the performance of Widal test in our hospital for diagnosis of typhoid fever in children. Hundred consecutive pediatric in-patients for whom, the Widal test was requested were grouped into four categories: widal positive and clinically consistent with typhoid fever (Group 1; n=42), widal negative but clinically consistent (Group 2, n=12), widal positive but not clinically consistent (Group 3, n=12) and widal negative and also not clinically consistent (Group 4, n=34). The results were analyzed by the test performance criteria, namely, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) using culture-confirmed typhoid fever cases as the "true positives". RESULTS: We found that 7/100 patients had culture-proven typhoid fever. Using a cut off ≥ 50 for O agglutinins or ≥100 for H agglutinins, the Widal test gave a sensitivity of 71.43%, specificity of 47.31%, and a positive predictive value of 09.25% and a negative predictive value of 95.65%. CONCLUSION: The Widal test is an easy, inexpensive and relatively non-invasive but is not reliable in our set up because of a low PPV. There is a need for a more efficient rapid diagnostic test for typhoid fever.
Authors: Benedikt Ley; George Mtove; Kamala Thriemer; Ben Amos; Lorenz von Seidlein; Ilse Hendriksen; Abraham Mwambuli; Aikande Shoo; Rajabu Malahiyo; Shaali M Ame; Deok R Kim; Leon R Ochiai; John D Clemens; Hugh Reyburn; Harald Wilfing; Stephen Magesa; Jacqueline L Deen Journal: BMC Infect Dis Date: 2010-06-22 Impact factor: 3.090
Authors: Zulfiqar A Bhutta; Michelle F Gaffey; John A Crump; Duncan Steele; Robert F Breiman; Eric D Mintz; Robert E Black; Stephen P Luby; Myron M Levine Journal: Am J Trop Med Hyg Date: 2018-07-24 Impact factor: 2.345