
Repeated outbreaks of the Zaire strain of the Ebola virus (Ebola virions pictured above) in central Africa were caused by a recent spread of the virus, rather than by a long-persistent strain at each site. (Photo: Walsh et al.)Over the past ten years, separate outbreaks of the deadly Zaire strain of Ebola virus (ZEBOV) have killed hundreds of humans and tens of thousands of great apes in Gabon and the Republic of Congo--which harbor roughly 80% of the last remaining wild gorilla and chimpanzee populations. In a new study, Peter Walsh, Roman Biek, and Leslie Real combined genetic data with information on the timing and location of past ZEBOV outbreaks to support the hypothesis that a "consistently moving wave of ZEBOV infection" recently spread to outbreak sites in Gabon and Congo.

