A Santa Fe County woman who contracted hantavirus has been upgraded from critical to serious condition at University Hospital in Albuquerque.

The 25-year-old became ill sometime during the last week of April or first week of May. Hers is the first New Mexico hantavirus case of the year.

The woman was taken to University Hospital on May 7, said Sam Giammo, a spokesman for the hospital.

"She's been upgraded to serious, which obviously is a step in the right direction," Giammo said. "She's a little better off now."

The woman has been treated using a piece of equipment that was specifically modified by University of New Mexico researchers for use with hantavirus patients, called an Extracorporeal Membrane Oxygenation device.

The device essentially bypasses the lungs and allows the patient to breathe, Giammo said.

Symptoms of hantavirus, which develop between one and six weeks after exposure, include fever, muscle aches, chills, nausea, vomiting, diarrhea, abdominal pain and cough.

The Health Department is investigating the woman's home and her workplace. Officials can't say exactly where in the county she was because of state and federal regulations, said Deborah Busemeyer, a spokeswoman for the Department of Health.

"They have learned that she was in the middle of moving. There were a lot of boxes being taken out of storage, and there was some evidence of rodents." Hantavirus is contracted through exposure to infected rodent droppings.

It's unclear if the woman sought medical attention during the week or two that she was sick before going to University Hospital, Busemeyer said.

Diagnosing the disease early can be critical for a patient's survival, she added.

In 2008, two people in New Mexico contracted hantavirus, one from Taos County and one from Otero County. Both died.

The Health Department also reported two new cases of swine flu on Wednesday, in a 4-year-old girl from Curry County and a 22-year-old woman from Taos County.

There were still no swine flu cases in Santa Fe County as of Wednesday afternoon.

Contact Sue Vorenberg at svorenberg@sfnewmexican.com.