New York, Jan 31 (IANS): Researchers, including one of an Indian-origin, have identified 20 genes that can predict an individual's likelihood of developing a severe form of dengue fever with about 80 per cent accuracy.

The team from Standford University in the US, identified a gene-expression pattern that predicts which people infected with dengue -- a mosquito-borne virus that can cause fever and joint pain, among other symptoms -- are at highest risk for developing a severe form of the illness.

Every year, between 200 million and 400 million people in tropical and subtropical regions of the world contract dengue fever, and about 500,000 of those cases are fatal.

For the most part, people with the disease recover after receiving some fluids and a few days' rest, said Purvesh Khatri, Associate Professor at the varsity.

"But there's a smaller subset of patients who get severe dengue, and right now we don't know how to tell the difference," Khatri said.

Anywhere from 5 to 20 per cent of dengue cases will advance to severe.

Currently, to diagnose severe dengue the doctors wait to observe specific symptoms and results of laboratory tests that typically emerge in the late stages of the disease.

"These practices are not nearly sensitive or accurate enough, and some patients end up admitted to the hospital unnecessarily, while others are discharged prematurely," said Shirit Einav, Associate Professor.

The new set of genes, reported in the Cell Reports journal, can help identify predictive biomarkers that can help doctors reliably gauge the likelihood of severe dengue in patients who are newly symptomatic and use that information to provide more accurate care to help guide therapeutic clinical studies and, in the future, to guide treatment decisions.

The genes could serve as a basis for a targeted therapy for dengue, Einav said - but that's far on the horizon.