Creighton Researchers Report Findings on Prion Disease
Creighton University researchers may have discovered a previously unsuspected pathway, the nasal cavity, for the natural spread of prion diseases -- a class of diseases which includes "mad cow" disease -- among animals.
Anthony Kincaid, Ph.D., Creighton associate professor of physical therapy, and Jason Bartz, Ph.D., assistant professor of medical microbiology and immunology, reported their findings in the Feb. 14 online edition of Journal of Virology.
Their study demonstrates for the first time that prion infection can be experimentally spread by the inhalation of the agent into the nasal cavity.
Until now, scientists have largely focused on ingestion as the most likely way that animals acquire a prion disease in nature. However, the results of the two-year Creighton study that used hamsters indicates that the rodents contracted the illness when a relatively small amount of prion-infected brain homogenate was placed just below their nostrils.
While more studies need to be done to determine if the nasal cavity is a route for the natural spread of prion diseases in larger animals such as deer, elk, cattle and sheep, there are reasons to suspect this mode of transmission, the researchers said.
"Each of these species has a well-developed olfactory system (which contributes to the sense of smell) that is used for finding food, detecting predators and for reproductive purposes, therefore their nasal cavity is frequently directly exposed to elements of the environment that may contain prions," noted Kincaid, the study's principal investigator.
Prion diseases are a group of fatal neurodegenerative diseases and include chronic wasting disease (CWD), and bovine spongiform encephalopathy (BSE), commonly referred to as "mad cow" disease. While the reported incidence of BSE in this country is rare, CWD infects relatively large numbers of farmed and wild elk and deer in parts of several U.S. states and Canada with the highest incidence occurring in a geographical region that includes sections of Nebraska, Colorado and Wyoming.
The Nebraska tobacco settlement trust fund financed the study.