The feds were on the phone explaining that a 10-year-old boy had a strain of swine flu no one had ever seen before.
As Dr. Michele Ginsberg listened, her mind flashed back to the days before the AIDS virus had been identified, when people were showing up at emergency rooms in California with a mysterious pneumonia.
Ginsberg, community epidemiology chief for San Diego County, where the boy was from, picked through her reports of unusual deaths, looking for similar cases. Nothing jumped out that April 16. And the county veterinarian didn't have reports of sick pigs.
Ginsberg's office called the boy's mother to see if he had been in contact with pigs or other animals that could transmit flu to humans. If he hadn't, it was likely that the virus had spread between people -- the last thing an infectious disease expert wants to hear.
"No animal exposure," Ginsberg wrote in her notebook.
But the boy's brother had been sick with fever and cough about two weeks earlier.
"Big deal!" Ginsberg added to her notes.
The virus has now traveled to 21 states and 18 countries, infecting more than 700 worldwide and killing about 115, all deaths save one in Mexico. It has riveted flu scientists and public health officials around the world. It appears to be relatively mild, perhaps no more deadly than a typical seasonal flu. But if it infects enough people, even a tiny death rate could add up to more fatalities than would be seen in a normal season -- perhaps many more.
In its early days, though, the virus was just a curious swab in a vial. The boy who had provided it was already better.
No one might ever have learned more about it except that the boy happened to come from a military family, and his sample was among those the Naval Health Research Center in San Diego was collecting as part of a study on a new flu test.
It came back as influenza Type A. Beyond that, the results were confusing. The Navy sent it to two labs in Wisconsin for analysis, but they couldn't figure it out either.
The tests showed what it wasn't: the dreaded H5N1 bird flu or either of two well-known strains of seasonal flu. But that did not explain what it was.
A distant cousin
The sample arrived by FedEx at Michael W. Shaw's laboratory at the Centers for Disease Control and Prevention on April 15.
Inside the package were two vials. In each, a cotton swab floated on a liquid the consistency of an egg white. Shaw and his colleagues bathed the samples in a chemical solution to crack open the virus and expose its genes.
