Ebola outbreak traced to animal reservoir.

• Position: Hemorrhagic Fever

Scientists employed advanced genomic sequencing technology to identify a single point of infection from an animal reservoir to a human in the current Ebola outbreak in West Africa. This research also has revealed the dynamics of how the Ebola virus has been transmitted from human to human, and traces how the genetic code of the virus is changing over time to adapt to human hosts. Pardis Sabeti, senior associate member of the Broad Institute, Cambridge, Mass., and her team carried out the research.

The current Ebola outbreak now is the largest in history, with current estimates of 2,473 infections and 1,400 deaths since it began in late December 2013, according to the World Health Organization. This outbreak also is the first in West Africa and the first to affect urban areas.

There are no approved drugs for Ebola virus disease, though prompt diagnosis and aggressive supportive care can improve survival. The disease is characterized by high fever, headache, body aches, intense weakness, stomach pain, and lack of appetite. This is followed by vomiting, diarrhea, rash, impaired kidney and liver function, and, in some cases, internal and external bleeding.

To better understand why this outbreak is larger than previous ones, Sabeti led an extensive analysis of the genetic makeup of Ebola samples from patients living in affected regions. Joined by an international team of scientists, she used advanced technology to analyze the genetics of...