Mexican authorities are investigating claims that the
outbreak of swine flu originated from an industrial pig
unit.
Health officials said the first known case of the disease was
found two weeks before the first death, in a village where
residents have been protesting over pollution from a pig farm
part-owned by American pork processor
Smithfield Foods.
The country's environment ministers said inspectors had found no
sign of swine flu in pigs around the farm in the town of La Gloria,
Veracruz State, and that no infected pigs had been found in
Mexico.
A spokeswoman for Smithfield, the world's largest producer and
processor of pork products, said no clinical signs or symptoms of
swine flu had been found in its herds or employees.
The processor was working with officials who were investigating
possible sources of the outbreak, she added.
However, the local press has reported complaints from residents
who claim they have been made ill by water and air contaminated by
"manure lagoons" on the farm, which raises about 1m pigs a
year.
La Gloria was sealed off in February and sprayed with chemicals
after residents developed respiratory problems, which they blamed
on swarms of flies which were attracted to manure from the
farm.However Mexico's National Organisation of Pig Production and
Producers denied the industry is to blame for the outbreak and said
it was scientifically "not possible" for pigs to infect people with
the disease.
About 150 people have now died from the disease in Mexico, while
cases have now been confirmed in the UK and Spain.
The World Health Organisation has
raised its alert level to four, two stages short of a full
pandemic.