Transmission from animals to humans
Experts suspect that both viruses are transmitted to humans through an infected animal's bodily fluids. Examples include:
Blood. Butchering or eating infected animals can spread the viruses. Scientists who have operated on infected animals as part of their research have also contracted the virus.
Waste products. Tourists in certain African caves and some underground mine workers have been infected with the Marburg virus, possibly through contact with the feces or urine of infected bats.