THE EARLY DIAGNOSIS OF TYPHOID-FEVER PRIOR TO THE WIDAL TEST AND BACTERIOLOGICAL CULTURE RESULTS

In an attempt to evaluate various clinical and laboratory features ava ilable within 24 h of admission, prior to the Widal test and bacteriol ogical culture results as potential diagnostic aids in typhoid fever, we undertook a retrospective unit-based case control study in 90 febri le adult and paediatric patients admitted to King Edward VIII Hospital , Durban, South Africa with an initial diagnosis of typhoid fever. A t otal of 30 blood culture-proven typhoid fever patients (cases) were ma tched to 60 patients confirmed as not having typhoid fever (controls) by age, sex, race and severity of illness on admission. Features signi ficantly associated with a final diagnosis of typhoid fever were: a pr e-admission duration of fever greater than or equal to 7 days (odds ra tio (OR) 6.9); hepatomegaly (OR 3.2); a normal leucocyte count (OR 10. 8); a leucocyte count of < 10.0 x 10(3)/mm(3) (OR 30.2); and leucopeni a due to absolute neutropenia with a relative lymphocytosis (OR 11.8). Although the sensitivity, specificity and predictive values of any of these features cannot be used reliably to distinguish typhoid fever f rom other non-typhoidal febrile illness, it is concluded that leucopen ia due to absolute neutropenia with relative lymphocytosis, when prese nt, is highly suggestive of typhoid fever. A leucocyte count of > 10.0 x 10(3)/mm(3) (OR 0.03) provides strong presumptive evidence against such a diagnosis. (C) 1998 Elsevier Science B.V. All rights reserved.