Researchers have developed a method to identify the cause of epidemics, based on online reports about the symptoms, the season and the ratio of cases to fatalities.

Using data from the Internet outbreak reporting system ProMED–mail, researchers from Columbia University's Mailman School of Public Health applied this method to more than 100 outbreaks of encephalitis in South Asia.

The region has been recently identified as an emerging infectious disease "hotspot". The data was used to determine which of 10 infectious diseases was causing symptoms of encephalitis, and whether Nipah – a serious emerging infection – could be reliably differentiated from the others, the Journal of the Royal Society Interface reports.

Particularly noteworthy, according to study author Stephen S. Morse, professor of epidemiology at Columbia and an originator of ProMED– mail, was that unknown outbreaks in resource–poor settings could be evaluated in real time, leading to more rapid responses that could reduce the risk of a pandemic, according to a Columbia statement.

"Our approach is especially beneficial in resource–poor countries because of their limited surveillance capacity and lack of laboratories to diagnose unusual outbreaks," said Morse, who is also founder of ProMed.

"Such countries are often where new infectious diseases emerge," he added.