Comparative evaluation of Blood culture, Immunochromatographic test, Widal and Polymerase chain reaction for rapid diagnosis of Enteric fever.

Salmonella enterica serovar Typhi, the human-specific, causative agent of typhoid fever, causes an estimated 21 million new cases and 216,000 deaths every year. Accurate diagnosis to differentiate typhoid fever from other conditions is often difficult. Isolation of the causative organism remains the most effective diagnostic method in suspected typhoid fever. PCR based tests for detecting the causative pathogens of enteric fever have developed rapidly over the last decade. The present study was conducted to evaluate the different diagnostic methods like Blood culture, Immucheck antibody test widal and Polymerase chain reaction (PCR). Out of 104 patients 12 (11.5%) were blood culture positive. All the culture positive and three other cases 15 (14.4%) were reactive by Immucheck typhoid antibody test. In our study total 15(14.42%) cases were positive for the widal test on the basis of the set endemic titre for the Aligarh district. dH flagellin gene was detected in 27(25.9%) cases. dH Flagellin gene amplification in blood detected the highest number of cases. Considering the polymerase chain reaction as gold standard, sensitivity and specificity of blood culture was 44.44% and 100% respectively. Polymerase chain reaction is most sensitive and specific for the diagnosis of enteric fever.