(AP) — No one has identified ground zero in the H1N1 flu epidemic. Just where or when the new strain of influenza first jumped from a pig and began infecting people is a scientific mystery — one that a group of flu detectives is determined to solve.

Scientists are returning next week to La Gloria, where Mexico's earliest confirmed case of H1N1 flu was identified. They hope to learn where the epidemic began by taking fresh blood samples from villagers and pigs, and looking for antibodies that could suggest exposure to previous H1N1 flu infections.

Some experts argue that a thorough investigation could be key to preventing future epidemics.

And Mexico has another reason to care: If it can somehow rule out the possibility that La Gloria's pigs infected humans, then it can tell the world it wasn't to blame for the epidemic — that the never-before-seen H1N1 flu virus came from somewhere else.

More than half of La Gloria's 3,000 residents fell ill with flu symptoms weeks before the new virus was identified.

"I cannot understand it. I could almost bet that there were more infections related to this virus" in La Gloria, Carlos Arias told The Associated Press. Arias is leading a group of flu detectives from the Biotechnology Institute and the veterinary school of the National Autonomous University of Mexico back to the village at the invitation of the Veracruz state government.

Arias said his team also will examine environmental and sanitary conditions in homes where pigs are raised, and make recommendations to the Veracruz government aimed at reducing the potential for human infections.

Virginia-based Smithfield Foods, which jointly owns 72 farms in the area surrounding La Gloria, said it carefully vaccinates its herd, and has found no signs or symptoms of any kind of swine flu in its pigs or its employees anywhere in Mexico.

Source: AP

See more H1N1 articles.