Abstract:
Typhoid is endemic in almost all parts of Bangladesh. Widal test is one of the easily available tools in many areas of the developing countries for the diagnosis of typhoid fever. The interpretation of Widal test depends upon the baseline titer which is prevalent amongst healthy individuals in a particular geographical area. In the endemic areas, the healthy people may contain antibodies which are capable of reacting up to a variable titer in the Widal test due to a past exposure, vaccination and cross reacting antigens. Therefore, it varies widely from place to place and is referred to as the baseline titer of that area. The objectives of this study were to determine the average baseline titer of the apparently healthy students of a private medical college of Dhaka and to find out the correlation among age; sex and the history of typhoid fever, antibiotics and vaccines against typhoid in regard to the Widal titers. The blood samples were collected from 100 apparently healthy students over the period of five months. After collecting the blood, sera were separated and analyzed for the presence of the Salmonella antibodies using the Widal tube agglutination test. Among the 100 serum specimens which were tested, 59 were positive for TO from 1:20 to 1:80 and 27 were positive for TH from 1:20 to 1:80. Based on the above results of the study, it has been revealed that the cut-off titers of 1:80 for the TO and of 1:80 for the TH may be considered as diagnostic for typhoid fever in Dhaka, Bangladesh. Besides, the study showed that there is no correlation among the age; sex and the history of typhoid fever, antibiotics and vaccines against typhoid in regard to Widal titers.
