Each year, up to 396 million people are infected with the dengue virus (DENV), leading to an estimated 100 million dengue cases. Annually, hospitals around the globe admit around 500,000 victims (mainly children) with severe dengue. About 2.5% of those affected die, but in some regions, the fatality ratio can be as high as 20%. In fact, severedengue has become a leading cause of hospitalization and death among children in Asia and Latin America.
These WHO estimates on the burden of dengue are shocking. With incidence growing dramatically in recent decades, the WHO set outobjectives to ‘reduce mortality and morbidity from dengue by 2020 by at least 50% and 25% respectively’ in its Global Strategy for Dengue Prevention and Control 2012-2020.
The fight against severe dengue intensifies
One of the leading causes of death in patients with severe dengue is something called vascular leakage, in which fluids and small molecules flow out of blood vessels. In severe dengue, vascular leakage leads to the familiar symptoms of fluid accumulating in the lungs and other parts of the body, resulting in shock and circulatory failure. Otherwise healthy people can die in 24 to 48 hours.
A team of researchers at the School of Public Health at the University of California, Berkeley, are investigating how severe dengue causes vascular leakage. Led by Dr. Eva Harris, a professor of infectious diseases, their findings could open up new possibilities for saving the lives of people who are at risk of succumbing to severe dengue.
NS1 holds the key
Dr. Harris and her team have been studying dengue for many years, both at UC Berkeley and in Nicaragua through collaborative research projects. In the course of their research, they noticed a distinct protein that might play a fundamental role in bringing about vascular leakage in people with severe dengue – a non-structural DENV protein called NS1.