Tracking epidemic spread
27 Aug 2012
As a new outbreak of West Nile Virus unfolds in the US causing sickness and death, University of Oxford researchers have found a new way to efficiently track the virus and to help to predict where it is likely to hit next.
Researchers from the Oxford Martin School’s Institute for Emerging Infections, together with collaborators in California, Belgium and Edinburgh, have been studying the emergence and spread of West Nile Virus in America since the first case was reported in New York in 1999.
Their results, published in Proceedings of the National Academy of Sciences USA, show that by using virus genome sequences, researchers can study how fast the infection is transmitted and spread.
“By looking at how the virus mutates and evolves to map the spread, rather than epidemiological reports of outbreaks, we can see how different local outbreaks are related to each other,” said Principal Investigator, Oliver Pybus.
“Genome sequencing is getting quicker and cheaper all the time and gives us a revolutionary new way to measure the spatial spread of an epidemic. These measurements are vital to public health officers and medical practitioners, who need to know where and when people are likely to be affected by an outbreak, to deploy anti-viral drugs and healthcare in the right place at the right time,” he added.
West Nile Virus is spread primarily between mosquitoes and birds. Pybus’ research shows that the movement of West Nile Virus through North America is more complex than previously thought, and was driven by rapid long distance viral movements, most likely via bird migration. West Nile Virus is reported to have led to some 41 deaths in America so far this year.
Tracking the spread of an epidemic is a key strategy in combating infectious disease. These findings have far reaching implications for tracking and estimating the rate of spread of viruses such as influenza, HIV and Hepatitis C.
Researchers have been able to track the spread of the West Nile epidemic by monitoring the mutations of the virus. Co-author of the paper, Rebecca Gray explained: “A genome is the blueprint for any organism. Over time, genomes accumulate mutations and in the case of viruses, they do this very quickly. We found that by reading the genomes of viruses sampled from different places and times, we could reconstruct the movement of the virus across the whole continent.”
- Read the paper: Unifying the spatial epidemiology & molecular evolution of emerging epidemics Proceedings of the National Academy of Sciences USA
Institute for Emerging Infections
- More about West Nile Virus