Microbiological studies of blood specimen from presumptively diagnosed Typhoid Fever patients in Zaria, northern Nigeria.

Abstract

In this study, 315 blood samples were obtained from presumptively diagnosed typhoid patients who were referred for Widal serological test at four diagnostic centres in Nigeria. The blood samples were subjected to bacteriological investigations. Salmonella and non-Salmonella organisms isolated were identified according to standard identification schemes. The Salmonella serological O- and H-antigen titre values of the patients whose blood samples were cultured were also collated and compared with the bacteriological findings. There was generally low correlation between the antigenic (O and H) titre value and cultural isolation of the causative organisms of typhoid fever. However, as the O-antigen titre value increased from 1:20 to 1:160, the percentage of samples in which Salmonella spp. were isolated increased from 5.6% to 50%. There was also a significant variation in the percentage values among the four diagnostic centres (varying from 46% to 83% at O-tire value of 1:160). Beside Salmonella spp., other organisms comprising mostly members of the Enterobacteriaceae Family, Pseudomonas spp., and Streptococcus were isolated from the blood of patients presenting high O-antigen titre values.