A Harvard University study just published clues about the ever-spreading Ebola virus in West Africa that could impact how it is addressed internationally.

The research traced the outbreak’s contagion to a funeral held in Sierra Leone in May for the death of a healer who had been in contact with Ebola patients near Guinea. More than a dozen women were infected. The death of one man affected the fate of thousands.  

Scientists also found hundreds of genetic mutations which could help in attempts improve drugs and treatments of the virus. But the research isn’t over — the team is still receiving samples of the virus to study and understand.

The news comes in light of a World Health Organization announcement from Thursday, Aug. 28, that outlined how the Ebola epidemic could escalate to affect 20,000 individuals before the world regained control. Currently, more than 3,000 people from Guinea, Liberia, Sierra Leone and Nigeria have been infected. Half have died so far. Officials from the Democratic Republic of Congo confirmed that Ebola was present in samples from a remote village, but a different strain from the West African virus.