Performance of Dengue Diagnostic Tests in a Single-Specimen Diagnostic Algorithm.

Area of Science:

• Virology
• Immunology
• Infectious Diseases

Background:

• Traditional dengue diagnosis relies on immunoglobulin M (IgM) seroconversion, often requiring paired specimens and delaying clinical management.
• The limited utility of seroconversion testing in early disease necessitates alternative diagnostic approaches.
• Dengue virus (DENV) viremia and IgM antibody presence during the febrile phase offer a window for single-specimen diagnosis.

Purpose of the Study:

• To evaluate the diagnostic performance of real-time reverse transcription polymerase chain reaction (RT-PCR), nonstructural protein 1 (NS1) antigen detection, and IgM antibody testing for dengue diagnosis using single serum specimens.
• To establish an effective diagnostic algorithm for dengue utilizing early febrile phase samples.

Main Methods:

• Analysis of 1234 archived paired serum specimens from laboratory-confirmed dengue cases (2005-2011).
• Testing included real-time RT-PCR for DENV serotypes 1-4, NS1 antigen ELISA, and anti-DENV IgM ELISA.
• Evaluation of diagnostic yield across different days of illness onset.

Main Results:

• Within 1-3 days of illness onset, RT-PCR detected 82%-69% and NS1 antigen detected 90%-84% of cases.
• Anti-DENV IgM ELISA detected only 5%-41% of cases during this early period.
• A combined diagnostic algorithm using these tests over the 10-day febrile phase achieved ≥90% case confirmation.

Conclusions:

• A single serum specimen collected within the first 10 days of illness can accurately diagnose dengue.
• Combining molecular (RT-PCR) or NS1 antigen tests with IgM antibody detection enhances diagnostic sensitivity.
• This approach enables accurate identification of both primary and secondary dengue infections, improving clinical case management.