Polymerase chain reaction for rapid detection and serotyping of dengue virus in clinical samples

Abstract

This study describes the benefits of using reverse transcriptase polymerase chain reaction (RT-PCR) for the rapid detection and typing of dengue virus in clinical samples. Twenty-seven serum specimens from patients with dengue fever and dengue hemorrhagic fever in Colombia, Nicaragua, and Panama were directly subjected to RT-PCR for the detection of dengue virus. The resulting double-stranded DNA product was typed by a second round of PCR amplification (nested PCR) with type-specific primers, viral culture/indirect immunofluorescence (IIF), and enzyme-linked electroimmunoassay for IgM anti-dengue antibodies. The amplified virus genome was detected and typed within 8 hours. Nested RT-PCR, using viral culture and IIF as the gold standard, showed 100% sensitivity; 78% specificity; 69% positive predictive value, and 100% negative predictive value. It is noteworthy that two of the specimens whose results were positive with nested RT-PCR and negative with viral culture showed specific IgM antibodies. The results of the RT-PCR were in close agreement with those obtained through viral culture. This suggests PCR can greatly facilitate the rapid and early diagnosis of dengue infection.