Biomarkers to predict severity in dengue infection

Dengue is a mosquito bourne viral infection of the tropics and subtropics. It can lead to a severe haemorrhagic fever that can be fatal unless treated in hospital. At the early stages it is impossible to judge which patients are going to suffer the more severe symptoms and should be admitted to hospital. During epidemics literally thousands of cases can occur at the same time and completely overwhelm the hospital systems. This research aims to develop a simple predictor of disease severity which would allow the high risk patients to be admitted to hospital whilst those at lower risk could be managed at home.

Dengue virus is an emerging infectious disease the incidence of which is still increasing alarmingly. Most dengue infections are either asymptomatic or mild referred to as dengue fever (DF). However 1-5% of infections can lead to dengue haemorrhagic fever (DHF) that is characterised by a severe vascular leak that can lead to hypovolaemic shock haemorrhage and death. Untreated this condition can be fatal in about 20% whilst expert hospital treatment which consists mainly of careful fluid replacement and monitoring reduces mortality to well below 1%. Dengue puts a huge stress on the healthcare systems in developing countries where explosive outbreaks can literally overwhelm the hospital systems. An effective early test which would stratify patients into high and low risk of developing haemorrhagic fever would be very useful to target the high risk group for hospital admission. It may also have future utility in directing antiviral drug therapy should the current anti-dengue drug programmes come to fruition. At present there is no such early test before the relatively abrupt onset of the vascular leak and shock.