RAPID DIAGNOSIS OF TYPHOID-FEVER BY COAGGLUTINATION IN AN INDIAN HOSPITAL

Detection of Salmonella typhi infection by a co-agglutination assay fo r specific O, H and Vi antigens and by blood culture were compared for 110 patients with suspected typhoid fever. Blood cultures were positi ve for S. typhi in 25.5% of patients. Co-agglutination tests with pati ents' serum and with blood culture supernates gave positive results in 70.9% and 67.3% of cases respectively. S. typhi antigens Hd and 09 we re detected in patients' serum by co-agglutination in 96.4% of blood c ulture-positive, and 62.2% of blood culture-negative patients. Co-aggl utination results were uniformly negative with serum samples from a co ntrol group of 50 healthy individuals, 20 patients with febrile non-ty phoid infectious disease and 20 patients with non-infectious febrile d isease. Of the 25 patients with suspected typhoid fever who had not re ceived prior antibiotic treatment, 88% yielded positive blood cultures and 96% gave positive results in serum co-agglutination tests. By con trast, of the 85 patients who had received prior antibiotics, only 7% yielded positive blood cultures, but 63.5% gave positive results in se rum co-agglutination tests. Co-agglutination tests with serum offer a simple, rapid, sensitive, specific and economical method for the early diagnosis of typhoid fever.