By James Donahue

Within days after President Barack Obama returned to Washington from an important meeting with Latin American leaders, including a stop in Mexico City for a personal conference with Mexican President Felipe Calderon, people in Mexico are ravaged by a toxic new variety of influenza that may have already killed over 100 people.

The virus has quickly spread throughout the world, hitting travelers who also were in Mexico and people they are coming in contact with. But for these people, while they are getting very sick, they are recovering.

Was it a coincidence that this new, never-before-seen variety of influenza should break out in Mexico at about the same time President Obama came to visit? Or was it a biological attack that went awry?

A report in the UK Independent said Mr. Obama was in personal contact with Felipe Solis, a distinguished archaeologist who escorted the president through Mexico City’s anthropology museum the day before he died of “flu-like symptoms.” The story said Solis met Mr. Obama at a gala dinner held at the museum on April 16, before the president traveled to the Americas summit in Trinidad and Tobago.

The president was on alert about the possibility of coming in contact with a contagious virus, and escaped unscathed, Washington health officials report. The disease first struck in Mexico City on April 13, three days before Mr. Obama arrived.

At that time, however, nobody expected it to be as deadly as it has turned out to be.

The disease alarmed the World Health Organization and the U. S. Center for Disease Control after its sudden onset sickened more than 1,000 people and left about 70 victims in Mexico dead.

This virus is especially suspicious now that it has been found to contain genetic material from not only pigs but birds and humans “in a way researchers have not seen before.” One report noted that there are combinations of four known influenza viruses, two of them known to previously affect animals that somehow got mixed in this new strain.

Things like that don’t usually happen by accident. Viruses usually evolve as they jump from host to host, and the evolution continues for months if not years before they turn deadly to humans, if it happens at all. The world has been watching the avian flu, known as H5N1 for years, since it first jumped from chickens and other farm birds to humans in China some years ago. In some cases, however, researchers said they believe the avian flu also jumped into pigs. But to date, H5N1 has not turned as deadly as some medical researchers feared.

Now that the new virus has been unleashed, the WHO and CDC are keeping a close eye on this bug. The concern is that it could yet evolve into an even more deadly form and set the stage for a global pandemic.