Culture and
serology were performed on
blood and
serum samples collected at or shortly after admission from 473
patients presented with suspected clinical
typhoid. Clinical symptoms at first presentation including
confusion,
hepatomegaly,
splenomegaly,
abdominal pain,
anemia, and gastrointestinal
bleeding were non-specific as they were observed even more often in non-
typhoid patients.
Culture confirmed the
diagnosis in 65.3% of the
patients with
typhoid fever as the final
diagnosis. The
sensitivity (58%) and
specificity (98.1%) of a rapid dipstick assay for the
detection of S. typhi-specific
immunoglobulin M were somewhat lower than those of
culture but higher than those of the Widal test. The dipstick assay thus may well be used in the
serodiagnosis of
typhoid in situation where
culture facilities are not available. Combination of test results of dipstick and
culture improved
sensitivity to 82.5%. In
laboratories that perform
blood culture the dipstick assay may be used as a rapid
screening tests to facilitate a rapid
diagnosis.
Sensitivity of the dipstick assay strongly increased with duration of illness and was higher for
culture positive than for
culture negative
patients. Duration of illness, and different pathogen and host factors including
dose of
infection,
pathogenicity and antigenicity, and prior
antibiotic use are likely to influence the
immune response, therefore the result of the dipstick assay. Duration of illness and presence of S. typhi in the
blood are major factors that determine severity of
disease.