A putative fifth serotype of dengue - Potential implications for diagnosis, therapy and vaccine design

Dengue is now established as the world’s most important arboviral infection. This Aedes mosquitotransmitted pathogen is considered to be the cause of a major re-emerging tropical disease and significant public health concern. Four distinct but genetically similar serotypes of dengue virus, DENV 1-4, are responsible for provoking a spectrum of clinical symptoms in humans that range from mild fever to severe haemorrhagic manifestations. Recently, a phylogenetically more distant fifth serotype has been mooted. Confirmation of the identification of this virus is required before its status as DENV-5 can be formally recognized. Nevertheless, the possibility of a further serotype raises the spectre of those antidengue therapies and vaccines predicated on DENV 1-4 that are currently under clinical trial being intrinsically suboptimal. Hence, the potential impact of the existence of DENV-5 and other sylvatic arboviruses on the strategy to combat dengue fever and related pyrexias of unknown origin should be considered in order to refine guidelines for diagnosis, treatment, prevention and control.