Evaluation of serological diagnostic tests for typhoid fever in Papua New Guinea using a composite reference standard

Clin Vaccine Immunol. 2012 Nov;19(11):1833-7. doi: 10.1128/CVI.00380-12. Epub 2012 Sep 19.

Abstract

Typhoid fever remains a major global health problem. A major impediment to improving outcomes is the lack of appropriate diagnostic tools, which have not significantly improved in low-income settings for 100 years. We evaluated two commercially available rapid diagnostic tests (Tubex and TyphiDot), a prototype (TyphiRapid TR-02), and the commonly used single-serum Widal test in a previously reported high-burden area of Papua New Guinea. Samples were collected from 530 outpatients with axillary temperatures of ≥37.5°C, and analysis was conducted on all malaria-negative samples (n = 500). A composite reference standard of blood culture and PCR was used, by which 47 participants (9.4%) were considered typhoid fever positive. The sensitivity and specificity of the Tubex (51.1% and 88.3%, respectively) and TyphiDot (70.0% and 80.1%, respectively) tests were not high enough to warrant their ongoing use in this setting; however, the sensitivity and specificity for the TR-02 prototype were promising (89.4% and 85.0%, respectively). An axillary temperature of ≥38.5°C correlated with typhoid fever (P = 0.014). With an appropriate diagnostic test, conducting typhoid fever diagnosis only on patients with high-grade fever could dramatically decrease the costs associated with diagnosis while having no detrimental impact on the ability to accurately diagnose the illness.

Publication types

  • Evaluation Study

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Costs and Cost Analysis
  • Diagnostic Tests, Routine / economics
  • Diagnostic Tests, Routine / methods*
  • Diagnostic Tests, Routine / standards
  • Female
  • Fever / diagnosis
  • Fever / etiology
  • Humans
  • Infant
  • Male
  • Middle Aged
  • Papua New Guinea
  • Reference Standards*
  • Sensitivity and Specificity
  • Serologic Tests / economics
  • Serologic Tests / methods
  • Serologic Tests / standards
  • Typhoid Fever / diagnosis*
  • Typhoid Fever / pathology
  • Young Adult