Evaluation of four commercial real-time RT-PCR kits for the detection of dengue viruses in clinical samples.

Background: Dengue is the most frequent arthropod-borne viral disease worldwide. Because dengue manifestations are similar to those of many other febrile syndromes, the availability of dengue-specific laboratory tests is useful for the differential diagnosis. Timely and accurate diagnosis of dengue virus (DENV) infection is important for appropriate management of complications, pathophysiological studies, epidemiological investigations and optimization of vector-control measures. Several "in-house" reverse transcriptase-polymerase chain reaction (RT-PCR) methods have been developed to detect, type and/or quantify DENV. Standardized dengue RT-PCR kits with internal controls have been recently introduced, but need clinical evaluation. We assessed the performances of 4 commercial DENV real-time RT-PCR kits.

Findings: The 4 kits were evaluated using a panel of 162 samples positive with an existing in-place hemi-nested RT-PCR used for routine DENV-infection diagnosis in patients with acute-febrile disease. The panel included 46 DENV-1, 37 DENV-2, 33 DENV-3, and 46 DENV-4. Also, 70 negative serum specimens were used to determine specificity. Geno-Sen's Dengue 1-4 Real-Time RT-PCR kit was the only assay to provide quantification using standards, but lacked sensitivity for DENV-4 detection. The SimplexaTM Dengue RT-PCR assay, with 151 (93.2% [95% confidence interval, 89.3-97.1]) positive samples, had significantly higher sensitivity than the other 3 kits; in a complementary evaluation of 111 consecutive patients' samples, its performance and genotyping agreed with the hemi-nested gold-standard assay.

Conclusions: The SimplexaTM Dengue RT-PCR's good performance to detect and genotype DENV1-4 requires further evaluation in multicenter and prospective studies, particularly in settings of clinical diagnosis during dengue outbreaks.