Biology department makes breakthrough

A research project headed by Portland State professor Dr. Luis Ruedas and supported by two graduate students has revealed the presence of hantavirus in Oregon, which until this time had not been detected by the federal government’s scientists.

Hantavirus pulmonary syndrome is responsible for five known deaths in Oregon, including a Portland State professor, David Dennette, and is carried in various forms by species of rodents.

The virus turns into a disease in humans and attacks the respiratory system, allowing fluid to pass through lung lining, resulting in a death similar to drowning.

There is currently no treatment or vaccine for the many strains of hantavirus, some of which are much more dangerous than others, and Ruedas and his team are seeking to find exactly what strain is present in Oregon’s wildlife.

The nature of the virus is what has Ruedas fascinated.

“The healthier an infected human is, the more at risk they are,” Ruedas said. “With hantavirus, if you’re healthy, you’re dead meat. Once you get infected there’s nothing you can do, it’s too late.”

Not all forms of the virus manifest into deadly disease in humans, however. Mortality rates range from 1 percent to 40 percent throughout the 35 or so known strands around the globe. North America is home to 12 known strands of the virus, but it is yet to be determined which strand is in Oregon and whether it is a deadly one or not.

“It is possible that the strand in Oregon is one of the ‘unknown’ strands,” Ruedas said.

The project began in the spring of 2002 and has since revealed numbers that the Centers for Disease Control and Prevention could not produce in their search of Oregon habitats in 1997. In Tryon Creek Park, 5.4 percent of 37 mice tested were found positive, and 16 percent of the 65 mice taken from Forest Park were carrying the virus. Blood of mice from Oxbow Park is still being tested but could indicate the presence of the virus there, as well.

The first known case in the United States occurred on a reservation in the four corners region, which includes Utah, Arizona, New Mexico and Colorado, where a high school boy fell dead at his school dance after experiencing nothing more than a nagging cough and some difficulty breathing. His girlfriend died a couple weeks later of the same symptoms. The undetectability of the virus is what makes it hard to predict.

Contained in fecal matter of infected rodents, the virus is spread through the air and results in contamination once ingested. The larger the amount inhaled, the more at risk an individual is of not surviving if the strand is deadly.

Laurie Dizney, a Ph.D. student of biology at Portland State, and Phil Jones, a master’s student of biology at PSU who got his undergraduate degree from the University of Missouri, are investigating two different aspects of the project that will provide valuable information about the nature of the virus when completed.

Dizney is looking at evidence from other habitats of the world that indicate the likelihood of the virus in areas where diversity of species is slim, and is attempting to verify whether or not an abundance of wildlife does in fact reduce the chances of viral presence. If she can prove a larger diversity of animals directly correlates with a lower risk of infectious diseases among humans in the area, then the drive to conserve wildlife areas would gain much-needed support.

So far, there have been 24 cases in Washington, 36 in California and 16 in Idaho, compared to only five in Oregon, which raises the question of how much Oregon’s biodiversity plays a part.

Jones is focusing on the chemical make-up of the virus found in Oregon in comparison to other cases around the world, as well as how the DNA of the local mice compares to that of the rodent carriers from elsewhere.

“The name for the Oregon (strain) is Sin Nombre, which means ‘no name,'” Jones said.

Jones is working to find the sequence of the virus’ strain in Oregon so it can be compared to others in hopes of identifying its potential risk.