Disease, Parasites
Hit By Drouth, Too

SANTA FE — There’s a bright side to drouth, if only a small one: it can be just as hard on parasites and disease organisms as it is on everything else.

That appears to be proving out now in the parched Southwest. Drouth may be slowing the spread of rodent-carried illnesses like hantavirus and plague, the New Mexico Environment Department has suggested.

The dry weather has meant fewer seeds and plants for rodents to nibble on, and department officials say less food means fewer rodents.

Researchers believe hantavirus is transmitted when people breathe dust containing particles of waste matter from infected rodents, and the plague organism is generally transmitted by infected fleas.

Pam Reynolds, a department scientist who checks rodent burrows for infected fleas, said the flea count is low this year in the burrows.

But she warned: "People still have to be aware that plague exists in the rodent population. It doesn't completely disappear."

None of the fleas collected has tested positive for plague this year, she said.

A cat near Las Cruces tested positive for plague in February, but no cases have been reported since then, she said. There have been no human cases of plague this year in New Mexico.

Last year, there were 16 cases of plague in cats. The peak years for human plague cases were 1983, with 26 cases, and 1984, with 16 cases, said Paul Ettestad, public health veterinarian for the state Health Department.

In 1993, 19 hantavirus cases were reported in New Mexico. In 1994, New Mexico had four hantavirus cases, while two were reported last year.

No New Mexico hantavirus cases have been reported so far this year.

Robert Parmenter of the University of New Mexico, director of an ecological research program north of Socorro, said rodent populations are low this year except in Las Cruces, where spring rodent numbers were high.

But in other parts of the state, "if you compare it to the '93 hantavirus outbreak, we're easily at five to 10 percent of what (the rodent population) was back then," he said. "We were down last year, too."