A little information can go a long way when it comes to understanding rodent-borne infectious disease, as shown by a new study led by scientist John Orrock of the University of Wisconsin-Madison and colleagues.
The researchers studied wild deer mouse populations on the Channel Islands off the southern coast of California. The mice carry a variant of hantavirus--a disease spread by rodents--called Sin Nombre virus.
Results of the study appear in the May issue of the journal American Naturalist.
They show that just three ecological factors--rainfall, predator diversity and island size and shape--can account for nearly all the differences in infection rates between the eight islands.
The study also provides some of the first evidence to support a recent hypothesis that predators play an important ecological role in regulating disease--sometimes known as the "predators are good for your health" hypothesis.
"These findings support an emerging consensus that ecological factors such as food web structure and species diversity play a key role in determining the prevalence of zoonotic diseases and human health risk," says Alan Tessier, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which funded the research.
In humans, Sin Nombre virus causes Hantavirus Pulmonary Syndrome, a virulent and often fatal disease.
An outbreak of Sin Nombre virus in 1993 in the Four Corners area of the U.S. Southwest killed several people and brought national attention to the disease.
Learning what factors control the prevalence and spread of viruses like Sin Nombre within host populations is crucial for understanding the risks of animal-borne diseases.
"The ecological underpinnings of disease prevalence, its dynamics in natural populations and its transmission from animals to humans are important links that are still being deciphered," says Orrock.
|Contact: Cheryl Dybas|
National Science Foundation