A dry-format field-deployable quantitative reverse transcriptase-polymerase chain reaction assay for diagnosis of dengue infections.

We have systematically evaluated a dry-format, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assay developed by Tetracore Inc. for the Cepheid SmartCycler platform to facilitate rapid diagnosis of dengue virus infections. A panel of related flaviviruses was used to evaluate the clinical specificity of the assay, and it was found to be specific to dengue. Eighty-one clinical samples previously confirmed dengue positive by virus isolation, along with 25 dengue negative control specimens were used to validate this new diagnostic assay. Using these clinical samples, the assay exhibited 98.77% sensitivity and 100% specificity. Over 85% of the clinical specimen exhibited viral loads ranging from 10(3) to 10(7) plaque-forming units per milliliter (PFU/mL). In addition, this dry-format assay is stable at ambient temperatures and requires minimal technical expertise to perform in a small thermocycler platform. These characteristics make it a promising candidate for diagnosis of dengue in mobile laboratories in the field.