Smithfield: no reason to believe that the virus is in any way connected to its operations in Mexico

Early today the US owner of an industrial pig production facility around 12 miles from La Gloria said it had found no clinical signs or symptoms of swine flu in its herd or Mexican employees. The world's biggest pig meat producer, Virginia-based Smithfield, said it is co-operating with the Mexican authorities' attempts to locate the possible source of the outbreak and will submit samples from its herds at its Granjas Carroll subsidiary to the University of Mexico for tests.

"Based on available recent information, Smithfield has no reason to believe that the virus is in any way connected to its operations in Mexico," it said in a statement. "The company also noted that its joint ventures in Mexico routinely administer influenza virus vaccination to their swine herds and conduct monthly tests for the presence of swine influenza."

The statement came after Mexico's national public health authority, the Mexican social security institute, raised concerns that waste from the Granjas Carrol facility may be responsible for the outbreak of illness, according to local media.

"According to state agents of the Mexican social security institute, the vector of this outbreak are the clouds of flies that come out of the hog barns, and the waste lagoons into which the Mexican-US company spews tons of excrement," reported Mexico City newspaper La Jornada.

Swine flu can be caught through contact with infected animals, but it is unclear if contact with flies or excrement has the same effect.

A La Gloria resident who spoke to the Guardian on condition of anonymity yesterday described how illness swept through the village. "Some people started getting ill in February and an eight-month-old baby died," she said. "After that another baby died on 21 March. Suddenly most of the village got ill. It was weekend and the tiny clinic here was closed. The state health authorities then did send doctors and nurses to look after us, and give us medication. About 60% of the village were ill and we asked them what it was and they said it was a severe and atypical cold. We talked about influenza and they said that was impossible, that influenza had been eradicated from Mexico."