What do you get if you cross bird flu with the 2009 pandemic human virus, widely known as swine flu? Unfortunately, the answer isn’t funny. a new study predicts that swapping genes between the avian and human influenza viruses may result in an even more dangerous flu.

The human influenza virus H1N1 that caused the 2009 flu pandemic, and H9N2, an avian influenza virus that is endemic in bird populations in Asia, are close cousins—close enough that they can swap genes if they find themselves in the same cell, resulting in new viruses that are a patchwork of the parent strains. Scientists suspect that some gene combinations may result in a particularly potent form of flu and ignite a pandemic in humans. but because these viruses are more likely to meet in the lungs of an Asian chicken farmer than under the nose of a virologist, researchers find it difficult to predict which gene combinations might be the most virulent and contagious.

So instead of waiting and seeing, researchers have played matchmaker and thrust the two viruses together in a test tube. a team in China generated 127 hybrid viruses and injected each one into lab mice. more than half of the hybrids were as good as their parent strains at infecting the mice, and eight of them proved to be more pathogenic, the team led by Jinhua Liu of the China Agricultural University in Beijing reports online today in the Proceedings of the National Academy of Sciences.

“These are important experiments”, says virologist Peter Palese of Mount Sinai Medical Center in New York City, who was not involved in the work. the viral hybrids that the Chinese team has identified are the ones that scientists might want to watch out for worldwide, he says. If these strains were recognized early, governments could launch a speedier response.

Creating highly virulent viruses in the lab is controversial, says virologist Ab Osterhaus of the Erasmus University Medical Center in Rotterdam, the Netherlands. “[But] I don’t think we should shy away from these experiments. … the more information we have, the better,” he says.

He explains, however, that the hybrids that are the most virulent in mice will not necessarily be the most dangerous in humans, nor the most contagious. “Mice mirror, to a certain extent, what happens in humans,” he says, but they are not perfect model animals. Liu agrees. He plans to investigate how contagious his new viral blends are in guinea pigs and ferrets—animals whose respiratory system better reflects our own feverish battle with flu.

By the Canadian Press

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TORONTO – A new look at last year’s flu pandemic finds that two-thirds of hospitalizations for the H1N1 flu were in a five-week period beginning at the end of October.

The study by the Canadian Institute for Health Information says that during those five weeks, H1N1 accounted for 3.4 per cent of hospitalizations across the country.

That was more than the percentage for heart attacks or for strokes.

The institute says that in Ontario, one in four emergency visits during October and November 2009 were by patients with flu-like symptoms — compared to about one in seven in previous years.

Overall, the study finds there were more than 15,000 confirmed and probable H1N1 hospitalizations from April to December — about 6,500 more patients than the number of lab-confirmed hospitalized cases previously reported.

Jeremy Veillard, vice-president of research and analysis at the institute, says the impact of the virus on hospitals was significant and much higher than originally estimated — and it’s good news that hospitals were able to weather the storm.

The estimated cost of H1N1 for hospitals was approximately $200 million, the CIHI study said, including $128 million during the busiest five weeks. the estimates don’t include physician fees.

“As the first global pandemic in more than 40 years, the response to H1N1 from public health authorities was unprecedented,” Veillard says in a statement released Tuesday.

Kathleen Morris, head of emerging issues at CIHI, says the study shows that Canada’s hospitals were able to build on what was learned during the SARS crisis in 2003, and cope with the high number of H1N1 patients.

The influx was dealt with in a number of ways, the study found.

In some cases, patients who typically would have been in intensive care units were moved to other wards and monitoring was increased.

And some hospitals delayed the admission of patients who were scheduled for elective surgery.