Clinical applicability of single-tube multiplex reverse-transcriptase PCR in dengue virus diagnosis and serotyping

This study has evaluated the clinical applicability of a single-tube multiplex RT-PCR as compared with a two-step nested RT-PCR for the diagnosis as well as serotyping of dengue virus in patient's samples. Seventy-six acute phase blood samples collected from clinically suspected dengue patients during the 2008 outbreak were subjected to two-step nested RT-PCR and single-tube multiplex RT-PCR for dengue diagnosis and serotyping. Of the 76 samples, 17 (22.4%) were positive for dengue viral RNA. Single dengue virus infection was found in 16 cases and 1 had concurrent infection with two serotypes (3&1). Dengue serotype 3 was the predominant serotype (70.5%), followed by serotype 1 (23.5%). Single-tube multiplex PCR had concordant result with that of two-step nested RT-PCR including the one with concomitant infection. This study reveals the predominance of dengue serotype 3 in North India in addition to the co-circulation of multiple serotypes and concomitant infection. The rapid and accurate diagnostic capability of single-tube multiplex RT-PCR used in the study appears to be promising enough to be commonly used for dengue viral detection as well as serotyping.