title: Evaluation of the Widal tube agglutination test for the diagnosis of typhoid fever among children admitted to a rural hdospital in Tanzania and a comparison with previous studies.
abstract: BACKGROUND
  The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi). However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability.
  
  
  METHODS
  We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives."
  
  
  RESULTS
  We found that 16 (1%) of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies.
  
  
  CONCLUSIONS
  Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of > or = 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable.
authors.affiliation: International Vaccine Institute, Seoul, Korea. bnley@ivi.int
authors.forename: Benedikt
authors.initials: B
authors.lastname: Ley
authors.forename: George
authors.initials: G
authors.lastname: Mtove
authors.forename: Kamala
authors.initials: K
authors.lastname: Thriemer
authors.forename: Ben
authors.initials: B
authors.lastname: Amos
authors.forename: Lorenz
authors.initials: L
authors.lastname: von Seidlein
authors.forename: Ilse
authors.initials: I
authors.lastname: Hendriksen
authors.forename: Abraham
authors.initials: A
authors.lastname: Mwambuli
authors.forename: Aikande
authors.initials: A
authors.lastname: Shoo
authors.forename: Rajabu
authors.initials: R
authors.lastname: Malahiyo
authors.forename: Shaali M
authors.initials: SM
authors.lastname: Ame
authors.forename: Deok R
authors.initials: DR
authors.lastname: Kim
authors.forename: Leon R
authors.initials: LR
authors.lastname: Ochiai
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.forename: Hugh
authors.initials: H
authors.lastname: Reyburn
authors.forename: Harald
authors.initials: H
authors.lastname: Wilfing
authors.forename: Stephen
authors.initials: S
authors.lastname: Magesa
authors.forename: Jacqueline L
authors.initials: JL
authors.lastname: Deen
mesh_terms: D000293:Adolescent; D000372:Agglutination Tests / Q000379:methods*; D001431:Bacteriological Techniques / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D003906:Developing Countries; D006761:Hospitals; D006801:Humans; D007223:Infant; D011237:Predictive Value of Tests; D012424:Rural Population; D012485:Salmonella typhi / Q000276:immunology*; D012680:Sensitivity and Specificity; D013636:Tanzania; D014435:Typhoid Fever / Q000175:diagnosis*