Redefining typhoid diagnosis: what would an improved test need to look like?

Area of Science:

• * Infectious Disease Diagnostics
• * Microbiology and Public Health

Background:

• * Typhoid fever causes millions of illnesses and deaths globally, particularly in developing nations.
• * Current point-of-care (POC) diagnostic tests for typhoid exhibit suboptimal sensitivity and specificity.
• * Inaccurate diagnostics contribute to widespread antibiotic overuse and the rise of multidrug-resistant strains.

Purpose of the Study:

• * To establish a comprehensive target product profile (TPP) for a next-generation typhoid diagnostic test.
• * To guide the development of improved diagnostic tools for resource-limited settings.
• * To address the urgent need for accurate and accessible typhoid fever detection.

Main Methods:

• * A structured literature review was performed to create a draft TPP.
• * The draft TPP included 36 desired characteristics for next-generation typhoid tests.
• * A Delphi survey of key stakeholders refined the TPP.

Main Results:

• * Next-generation typhoid diagnostic tests should achieve ≥90% sensitivity and ≥95% specificity.
• * Ideal tests will function in settings with limited power and water, providing results in under 15 minutes.
• * The target cost for these advanced tests is less than US$1.00.

Conclusions:

• * This TPP represents the first comprehensive guide for developing next-generation typhoid diagnostic tests.
• * Accurate POC diagnostics will significantly reduce typhoid-related morbidity and mortality.
• * Integrating typhoid diagnostics into broader febrile illness testing algorithms is key to combating antimicrobial resistance.