The baby girl recovered and no other cases have been reported but flu experts are on alert because the virus was similar to a strain found in pigs, which scientists suspect was the source of the Spanish flu pandemic earlier this century.
"Although health officials are anxious not to cause panic, the Hong Kong strain is being monitored closely because it seems to have jumped from pigs -- the animals thought to have been the origin of the 1918 Spanish flu pandemic that killed an estimated 20 million people worldwide," the weekly magazine said.
Virologists at the National Institute for Medical Research in London and the U.S. Centers for Disease Control and Prevention in Atlanta are studying samples of the virus.
Alan Hay, the director of the WHO influenza collaborating center in London told the magazine the case is being looked at very carefully.
"We don't know the ins and outs of this yet," he said. "It's at quite a preliminary stage."
Other cases of swine viruses have been reported and were harmless but scientists are taking no chances. Many believe another flu pandemic is already overdue.
Researchers are not sure what causes a pandemic but they think new strains that originate in birds or pigs cross over to humans who have no immunity against it.
Six people were killed in a flu scare in Hong Kong two years ago when they were infected with a strain of the virus from chickens. The scare led to the mass slaughter of birds in Hong Kong.