Detection of Salmonella enterica, Subsp enterica Serovar Typhi in Dengue Virus Seropositive Samples

Dengue virus infections and typhoid fever are among the endemic diseases in tropical and sub tropical regions of world. Bacteraemia with dengue co-infection is rare. Present study was designed to detect dengue virus RNA and then to test those samples for the detection of S typhi to check the co infection rate of these two infectious agents in Pakistani population. A total of 365 subjects were included in this study, out of which 224 (61.7%) were males and 141(38.2%) were females. The median age of patients was 40 +/- 32, percentage of dengue positive samples was found to be higher in age group 31y-40y and 41y-50y.75 % of total samples included in the study were positive for dengue virus RNA where as 24.6% were those in which dengue virus RNA was not detected. DENV-2 was found to be the most prevalent serotype while DENV-1, DENV-3 and DENV-4 were not detected in any of the sample. Of the 274 samples with DENV-2, only 4 samples were positive for S typhi. S. typhi was also detected in 3 patients who were negative for dengue virus PCR. The presence of S. typhi in dengue positive samples was further confirmed by sequencing PCR products.