Researchers Isolate Hantavirus Linked to Deaths in Southwest

Medical researchers have isolated a hantavirus in the laboratory, taking the first step toward controlling the often lethal rodent viruses blamed in the deaths of at least 27 people in the Southwest.

“It is important to try to grow an organism so you can kill it,” said Dr. Howard Levy, a University of New Mexico professor.

The announcement came on the final day of a two-day conference on hantaviral disease that drew about 400 people.

About 45 hantavirus cases have been identified in the United States since the disease was first recognized in the Four Corners area of the Southwest six months ago. Studies of unexplained respiratory illness found one case as early as September, 1990.

The as-yet-unnamed hantavirus is believed spread through airborne particles from the urine and feces of infected rodents, particularly deer mice.

Producing the hantavirus in the lab allows scientists to study how it interacts with cells, how it matures and how to block it.

Researchers took lung tissue from an infected mouse, injected it into the tissue of a second mouse, and from that one into the tissue of a third mouse. The cell culture was then incubated and examined at two-week intervals.

It’s important to have a laboratory virus to work with because “it’s difficult to work on humans because of what you can’t do to them,” Levy said.

The hantavirus has mutated enough that it can grow in cells, which it couldn’t do before, said Connie Schmaljohn, chief of the department of molecular virology for the U.S. Army Medical Research Institute of Infectious Diseases in Maryland.

A hantavirus also appears to have been cultivated in a human cell culture, but “it will be a few weeks before we can really say it’s isolated,” Schmaljohn said.

The virus can be spread only from rodents to humans, not from one person to another, so outbreaks can be contained by controlling rodent populations, says virologist Stephen S. Morse, author of the book “Emerging Viruses.”