The Indian Journal of Pediatrics

, Volume 74, Issue 10, pp 909–913 | Cite as

Diagnosis of typhoid fever by polymerase chain reaction

Original Article



To determine the efficacy of nested polymerase chain reaction (PCR) in detecting Salmonella typhi gene sequences in blood and urine specimens and to determine the cut-off titer of Widal test using PCR as gold standard test for diagnosis of typhoid fever.


Study included 71 children between the ages of 8 months and 14 years; 52 of them were suspected cases of typhoid fever, 11 were febrile non-typhoid controls, and 8 were apparently healthy children. Nested PCR in Blood and Urine, Blood culture, Widal test and Urine culture were done and their results analyzed.


Among suspected typhoid cases, PCR in blood and urine had positivity of 82.7% each. Blood culture, Widal test (at cut off titer TO and / or TH ≥ 1:160) and urine culture had positivity of 26.9%, 50% and 3.8% respectively. In one case, urine PCR was positive and blood PCR was negative. Similarly, in another case, PCR in blood was positive however urine tested negative. Considering PCR as gold standard, the antibody cut off titer was evaluated. A cut-off titer of TO ≥ 1:80 and/or TH ≥ 1:160 had sensitivity and specificity of 72.7% and 84.2%, while the respective figures were 50% and 89.5% when the cut-off titer was TO and/or TH ≥ 1:160.


The sensitivity, specificity, positive and negative predictive values, likelihood ratios were same for PCR based detection of S. typhi in blood and urine samples. Nested PCR had higher efficacy in detecting typhoid fever than Widal test, blood and urine cultures. A cut off titer of TO ≥ 1:80 and/or TH ≥ 1:160 was found to have better diagnostic value in this region.

Key words

Blood culture Polymerase chain reaction Salmonella typhi Typhoid fever Widal test 


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  1. 1.
    Ivanoff B, Levine MM, Lambert PH. Vaccination against typhoid fever, Present status. Bull WHO 1994; 72: 957–971.PubMedGoogle Scholar
  2. 2.
    Hoffman SL, Edman DC, Punjabi NH et al. Bone marrow aspirate culture superior to streptokinase clot culture and 8 ml 1:10 blood to broth ratio culture for diagnosis of typhoid fever. Am J Trop Med Hyg 1986; 35: 836–839.PubMedGoogle Scholar
  3. 3.
    Forsyth JRL. Typhoid and Paratyphoid. In Forsyth JRL, ed. Topley and Wilson’s Microbiology and Microbial Infections. Vol. 3., London; Arnold, 1998; 459–478.Google Scholar
  4. 4.
    Rubin FA, McWhirter PD, Punjabi NH et al. Use of a DNA probe to detect Salmonella Typhi in the blood of patients with typhoid fever. J Clin Microbiol 1989; 27: 1112–1114.PubMedGoogle Scholar
  5. 5.
    Song JH, Cho H, Pank MY, Na DS, Moon HB, Pai CH. Detection of S. typhi in the blood of patients with typhoid fever by PCR. J Clin Microbiol 1993; 31: 1439–1443.PubMedGoogle Scholar
  6. 6.
    Frankel G. Detection of Salmonella Typhi by PCR. J Clin Microbiol 1994; 32: 1415.PubMedGoogle Scholar
  7. 7.
    Hashimoto Y, Itho Y, Fujinaga Y et al. Development of Nested PCR based on ViaB sequence to detect S. typhi. J Clin Microbiol 1995; 33: 775–777.PubMedGoogle Scholar
  8. 8.
    Old DC, Threlafall EJ. Salmonella. In Forsyth JRL, ed. Topley and Wilson’s Microbiology and Microbial Infections. Vol. 2., London; Arnold, 1998; 970–997.Google Scholar
  9. 9.
    Prakash P, Mishra OP, Singh AK, Gulati AK, G Nath. Evaluation of nested PCR in diagnosis of typhoid fever. J Clin Microbiol 2005; 43: 431–432.PubMedCrossRefGoogle Scholar
  10. 10.
    Greenberg RS, Daniels RS, Flanders WD, Eley JW, Boring JR. Diagnostic testing. In Medical Epidemiology. New York; McGraw-Hill; 1996; 77–88.Google Scholar
  11. 11.
    Gillman RH, Terminel M, Levine MM, Hernandez-Mendoza P, Hornick RB. Relative efficacy of blood, urine, rectal swab, bone marrow and rose spot cultures for recovery of Salmonella Typhi in typhoid fever. Lancet 1975; 11: 1211–1213.CrossRefGoogle Scholar
  12. 12.
    Chaudhary R, Laxmi BV, Nisar N, Ray K, Kumar D. Standardization of PCR for the detection of S. Typhi in typhoid fever. J Clin Pathol 1997; 50: 437–439.CrossRefGoogle Scholar
  13. 13.
    Haque A, Ahmed J, Quereshi J. Early detection of Typhoid by Polymerase Chain Reaction. Ann Saudi Med 1999; 19: 337–340.PubMedGoogle Scholar
  14. 14.
    Massi MN, Shirakawa T, Totoh A, Bishnu A, Hatta M, Kawabata M. Rapid diagnosis of typhoid fever by PCR assay using one pair of primers from flagellin gene of Salmonella Typhi. J Infect Chemother 2003; 9: 233–237.PubMedCrossRefGoogle Scholar
  15. 15.
    Bal AE, Gravekamp C, Hartskeerl RA et al. Diagnosis of leptospires in urine by PCR for early diagnosis of leptospirosis. J Clin Microbiol 1994; 32: 1894–1898.PubMedGoogle Scholar
  16. 16.
    Fuentes I, Rodriguez M, Domingo CJ, Castillo FD, Juncosa T, Alwar J. Urine sample used for congenital toxoplasmosis diagnosis by PCR. J Clin Microbiol 1996; 34: 2368–2371.PubMedGoogle Scholar
  17. 17.
    Whiley DM, Lecornec GM, Mackay IM, Siebert DJ, Sloots TP. Real-time PCR assay for the detection of Neisseria gonorrhoeae by Light cycler. Diag Microbiol Infect Dis 2002; 42: 85–89.CrossRefGoogle Scholar
  18. 18.
    Rasaily R, Dutta P, Saha MR et al. Value of single Widal test in the diagnosis of typhoid fever. J Clin Microbiol 1993; 97: 104–107.Google Scholar
  19. 19.
    Shukla S, Patel B, Chitnis DS. Hundred years Widal test and its reappraisal in the endemic areas. Ind J Med Res 1997; 105: 53–57.Google Scholar
  20. 20.
    Olapoenia LA, King AL. Widal agglutination test-100 years later: still plagued by controversy. Prostgrad Med J 2000; 76: 80–84.CrossRefGoogle Scholar

Copyright information

© Dr. K C Chaudhuri Foundation 2007

Authors and Affiliations

  1. 1.Miami Childrens HospitalMiamiUSA
  2. 2.Department of Microbiology, Institute of Medical SciencesBanaras Hindu UniversityVaranasiIndia
  3. 3.Department of PediatricsB.P. Koirala Institute of Health SciencesDharanNepal

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