May 1, 2009—When Maria Adela Gutierrez died just weeks ago, her illness was a mystery. Now, experts have uncovered clues as to how she became Mexico's first fatality in the 2009 swine flu outbreak.

© 2009 National Geographic (AP)

Unedited Transcript

Mexicos first confirmed death from the H1N1 strain of influenza, known commonly as swine flu, happened more than a week before doctors confirmed her ailment.

The 39-year-old door-to-door tax inspector was hospitalized with acute respiratory problems.

Maria Adela Gutierrez had symptoms much like this woman now in the hospital, but doctors couldnt figure what was wrong with her. She arrived gasping for air her hands and feet blue from oxygen-starved blood.

They administered antibiotics, but she only got worse. They put her on a ventilator, and sent test samples to a lab.

On her third day, test results indicated coronavirus.

SOUNDBITE (Spanish) Jesus Manuel Salcedo Cruz, Gen. Director, Hospital Gral. Dr. Aurelio Valdivieso: "Her evolution from day 9 to day 10, and the lab tests that were done, showed that it was not a typical case, as with other pneumonias contracted in the area. She presented altered liver enzyme function and low leukocytes, which implies a different type of problem."

A day later Gutierrez died. And it was days later before her illness was identified as a mutated swine flu virus.

Four houses away from Gutierrezs, Hermelinda Leon, her husband and three children were all ill with similar symptoms.

SOUNDBITE (Spanish) Hermelinda Leon Gomez, Neighbor of Adela Maria Gutierrez: "In fact, eight to fifteen days before she died my entire family was very sick as well. It was a terrible illness that we went through. In fact, I think it was the same illness."

They all recovered.

The Associated Press reports that neighbors say Gutierrez had been working alongside a temporary worker from Veracruz, the state where Mexicos earliest case of swine flu was confirmed: 5-year-old Edgar Hernandez, who survived.

About 450 people in the town of La Gloria were diagnosed with acute respiratory infections, but only a few dozen were tested for the new virus.

And Mexicos health minister claims Edgars sample is the only one that came back positive.