Where in the world do outbreaks begin? Kathmandu, Nepal presents challenges to researchers trying to hunt down the source of typhoid infections in that city. Without the marked streets and other infrastructure enjoyed in the West, researchers tackled the challenging hunt with DNA analysis and GSP technology. Then they mapped the sources of infections with Google Earth.
To map these infection sources in the city, typhoid patients' pathogenic DNA was analyzed; research team members then went to the patients' homes and mapped them with GPS systems. By measuring the changes in the DNA from patient samples and correlating those data to locations, the group was able to determine that patients living near waterspouts or in areas of low elevation were at a high risk of contracting typhoid.
"Until now, it has been extremely difficult to study how organisms such as the typhoid-causing bacteria evolve and spread at a local level," Dr. Stephen Baker from the Oxford University Clinical Research Unit in Vietnam, said in a statement. "Without this information, our ability to understand the transmission of these diseases has been significantly hampered. Now, advances in technology have allowed us for the first time to create accurate geographical and genetic maps of the spread of typhoid and trace it back to its sources."
The Oxford research teams in Kathmandu and Ho Chi Minh City, Vietnam worked with the Welcome Trust Major Overseas Program in Vietnam on the research, which has been described in the journal Open Biology.
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