(Photo by Mai Mohamed - CDC)

A April 2014 polio eradication campaign in Egypt.

Last September, poliovirus type 2 was declared eradicated after the last known case was reported in 1999. Now there are calls to eliminate samples remaining in labs. But with an Arizona lab working to eliminate two other known types, researchers are left in a compromising position.

The Global Polio Eradication Initiative is calling on most of the near 500 laboratories to destroy their poliovirus type 2 samples. The proposed plan would leave 50 labs with virus samples in much higher regulated environments.

Although Kurt Gustin’s lab at the University of Arizona’s College of Medicine in Downtown Phoenix is working exclusively with types 1 and 3, he said the welcome news about type 2 eradication also has trade-offs.

“Making more difficult access to a wonderful model system to study viruses like polio," said Gustin. "Because it was so intensely studied in the United States from the '50s onward, we have innumerable resources available and understanding of this virus that’s come from this research and the investment of public money in it.”

Poliovirus type 3 was last detected in 2012, and only 52 cases of type 1 have been reported this year, all in Afghanistan and Pakistan.