Thus, the Ebola-Reston subtype appears to be less capable of causing disease in humans than are the other subtypes of Ebola virus. However, much more study of Ebola-Reston virus is needed before definitive conclusions can be made about the pathogenicity of this subtype. The best information suggests that the Ebola-Reston virus is highly transmissible by injection or by droplets falling on the eye or other mucous membranes. There is no direct evidence of aerosol spread of the virus outside a laboratory setting. This means that these strains are all closely related and are the same virus species.
Viruses usually have differences in their genetic material when various strains are compared.
Thus, the changes found are not of any particular importance and are not unexpected. The reservoir and natural history of filoviruses remain unknown. Nonhuman primates are even more sensitive to infections with filoviruses than humans are. It seems likely that these animals serve as indicators of filovirus activity, but there is no evidence linking them to the maintenance cycle of the virus. At the request of the Texas Department of Health, CDC has sent medical scientists to Texas to assist state and local health officials in the investigation.