Viral characteristics and genomics of early onset, single organ specific presentations in dengue

Abstract

INTRODUCTION AND OBJECTIVES: Early onset neurological, hepatic and cardiac complications of dengue are increasingly recognized. However, doubts exist as to whether such complications of dengue are consequences of dengue shock syndrome rather than direct organ involvement. We studied virus characteristics and their genomics in patients who presented with early onset single organ involvement due to dengue, without features of DSS. METHODS: Blood samples were collected at admission of seven patients, who presented to the Professorial Medical Unit, Colombo North Teaching Hospital Ragama during 2011-2012, confirmed as having acute dengue by PCR. Samples were analysed with single-tube, nested RT-PCR using type-specific primers. Viral RNA was extracted and sequencing was performed. The dengue virus sequences were aligned with other sequences that are available in the GenBank and maximum-likelihood (ML) tree was made. RESULTS: Early onset organ specific manifestations included; self-limiting fits and clouding of consciousness on the 2nd day, rise in AST (1337iu/L) and ALT (749iu/L) on the 4th day and T wave inversions in the ECG on the 3rd day. Seven Dengue 1 viruses were isolated, which were in close homology in all 7 patients, based on the maximum likelihood tree with 1000 boot-straps. CONCLUSIONS: All the strains detected were clustered within the Genotype I clade of dengue-1 and in close homology with the dengue-1 viruses detected in the country in the recent past. The significance of viral characteristics and genomics related to organ specific manifestations need further study.