Mexico swine flu 'patient zero' was baby girl in February

"It's a six-month-old baby girl from San Luis Potosi who is alive" and first showed symptoms of the new strain of the influenza A(H1N1) virus on February 24, said Celia Alpuche of the Institute of Epidemiological Diagnosis and Reference (INDRE) in Mexico City.

Worldwide media honed in on two possible "patient zeros," including a five-year-old boy who lived near a pig farm in eastern Mexico and a woman from Oaxaca, in the southeast, after the government first raised the A(H1N1) alert exactly three months ago.

Both had contracted the virus, which has now killed more than 700 people worldwide, in April.

But studies carried out on a backlog of samples show that a first handful of recorded cases appeared in March in central and northern Mexico, before any showed up further south, said Alpuche.

"We have other positive samples in March from Baja California (northwest), San Luis Potosi and Mexico City (center)," Alpuche said, referring to results discovered around one month ago.

"It's complicated to say where it originated but the earlier samples are not from rural areas, that's to say areas with farms (or) pigs," she added.

Mexico's swine flu death toll now stands at 138, with almost 14,800 recorded cases, and the country has recently seen an upsurge of cases in the impoverished southeast.

(c) 2009 AFP