Aim: To compare the diagnostic efficacy of Diazo test vis-a-vis blood culture and Widal test in enteric fever in children.
Design: A randomized, open, controlled clinical trial in a teaching hospital in Moradabad.
Methods: One hundred twelve children suffering from enteric fever (based on suggestive clinical picture and either positive blood culture, Typhidot M or Widal in study group and 60 children with fever of confirmed aetiology other than enteric fever in control group were included in the study. Results of diazo test were compared with blood culture positive, Typhidot M positive or Widal.
Results: Of the 112 blood cultures, only 18 (16.1%) were positive for Salmonella typhi. In the first week of illness, Typhidot M was positive in 35 (89.7%) out of 39 cases whereas it was positive in all the 112 cases in the second week of illness. In the first week, only 4 (10.3%) out of 39 patients showed a positive Widal test. In the second week, 71 out of 73 new cases as well as all the 39 old cases showed positive Widal test. In the third week, 110 out the total 112 cases showed positive result. In the first week of illness, 27 (69.2%) out of 39 patients in the study group showed a positive diazo test. In the second week, 99 (88.4%) out of 112 patients in the study group showed a positive Diazo test. In the third week of illness, 81patients out of the total 112 cases had a positive Diazo test. Diazo test showed sensitivity, specificity, positive and negative predictive value, and likelihood ratio of positive and negative test of 88.4%, 93.3%, 96.1%, 81.2%, 13.2% and 0.12% respectively as compared to Typhidot M and 90%, 93.5%, 96.1%, 81.2%, 13.9% and 0.11% as compared to Widal and 88.9%, 11.7%, 16.1%, 84.6%, 1% and 0.95% as compared to blood culture.
Conclusion: Diazo test is a simple bedside, quick and cheap test with significant amount of reliability for the diagnosis of enteric fever in children.