MEXICO CITY (Reuters) - The 39-year-old woman who was the first to die in Mexico's swine flu epidemic spent the last eight days of her life going from clinic to clinic to find out what was wrong with her but doctors were baffled.
The woman, from the southern state of Oaxaca, died shortly after being admitted to hospital as an emergency case. Experts only identified the virus that killed her 10 days later.
The swine flu outbreak has killed as many as 159 people in Mexico, and forced the World Health Organization on Wednesday to warn that a global flu pandemic is imminent.
The woman, who worked as a census taker in the city of Oaxaca, became ill with what was she thought was a severe case of pneumonia on April 4 but was not admitted to hospital until April 12.
"She went to several private clinics where she was given various diagnoses and various treatments. However, her condition worsened and she was taken to the hospital by emergency services on the 12th and the next day she died," Miguel Angel Lezana, Mexico's chief epidemiologist, told reporters.
Authorities have not named the woman.
Mexican health officials are still scrambling to understand how the illness broke out. Attention has focused on a town in Veracruz state near a large pig farm where another confirmed case of swine flu in a human was detected.
But Lezana said the presence of Eurasian swine flu genes in the H1N1 virus makes it unlikely that the disease originated in a Mexican pig farm.
Oaxaca is one of Mexico's poorest states, but victims of the flu have been found in wealthier areas including the capital.
The cause of the woman's death was not determined until April 23 when a previously unknown flu virus combining strains of swine, bird and human flus was identified.
Recovery from the flu requires quick attention with antiviral drugs and equipment to assist patients with breathing, Lezana said.
Reporting by Robert Campbell; Editing by Cynthia Osterman