Two days ago, 13-year old Evan Frustaglio of Etobicoke, Ontario died of H1N1, also known as swine flu. As the father of an 11-year-old daughter and a 7-year-old son, my heart goes out to the family. To lose a child is the one thing no parent should ever have to endure.

Since Evan's death some of you have wondered whether I regret referring to the H1N1 outbreak as 'Swinefeld', a takeoff on the title of 'Seinfeld', which was described as a show about nothing. I do not.

Stories like Evan's are heart wrenching. But to really understand the behaviour of H1N1, you need to put his death in context.

Swine flu was and remains a high volume, low-acuity outbreak. The fact that H1N1 is a new virus means nobody is immune to it. That's very different from most new strains of seasonal flu, against which at least some of us possess at least some immunity. Whenever you have a brand new flu virus the entire population is at risk of getting infected.

That is what we are seeing with H1N1. Unprecedented numbers of Canadians have been, and will become, infected with the virus. The death rate from H1N1 is low -- on the order of 1 in 250,000 people infected with the virus. But this is a numbers game. When large numbers of Canadians are infected, even a virus with a low death rate will lead to some deaths.

That is what we are starting to see with the death of Evan Frustaglio and others. Since the first wave of H1N1 that started back in April of this year, a small number of people have died of complications such as pneumonia and heart failure. Since the beginning of the outbreak, some of those deaths have occurred in children and young adults.

There have been so few deaths in young people, that it's difficult to make generalizations. Earlier this week, the U.S. Centers for Disease Control reported that of the 1000 deaths that have occurred in the United States since the outbreak began, 95 have been in children. More than 80% of the deaths have occurred in children age 5 and up. Two-thirds have occurred in children with other medical problems such as cerebral palsy and severe asthma. Distressingly, one-third have occurred in otherwise healthy children -- kids like Evan Frustaglio. Public health officials say they can't pick out the small number of health kids who could die from H1N1 from the majority who will get a brief, albeit nasty illness from which they recover.

From reports in the media, it appears that Evan had no medical problems, apart from mild asthma. But did H1N1 simply strike and kill him out of the blue? Were there any factors during the course of his illness that -- apart from the virus -- may have played a role in his death?

A timeline that appears in the Globe and Mail on Wednesday, October 28 provides some clues. Last Friday, a classmate said that Evan complained of a sore back. He had travelled with his mother to a hockey tournament and played that day. That night, he complained of a sore throat. On Saturday, Evan complained of soreness and had mild flu symptoms. Again, he played hockey. That evening, he vomited several times. On Sunday, after vomiting all night, his mother took him to a walk-in clinic in Etobicoke, where the doctor advised that Evan take over the counter medications. The next night, he vomited several times. At around 11 am on Monday morning, he went limp and was rushed to hospital, where he died.

Assuming the timeline is correct, two things stand out in my mind. First, Evan played not one but two hockey games when he had H1N1. Most physicians will tell you that it's never a good idea to exercise vigorously when you have influenza, since doing so puts extra strain on the heart. Second, I suspect that Evan developed severe dehydration during his illness from the combination of vomiting and loss of fluid due to rigorous exercise. At exactly the time when he should have rehydrated himself by drinking fluids, he was vomiting because of H1N1.

Therefore, I think it's entirely possible that Evan collapsed not because of breathing trouble, but because of shock brought on by severe dehydration. In my experience, children can look relatively well and can appear to have a normal blood pressure yet be severely dehydrated. Collapse can occur without warning. By the time shock is easy to detect in children, it may be too late to save them.

So, what are the take home messages for worried parents? If your child has typical symptoms of H1N1, take them to your GP, the walk-in clinic, or the ER. Symptoms to look for include fever, sore throat, aches and pains, dry cough, and headache. Watch especially for trouble breathing, as that is a serious symptom. Kids with symptoms of H1N1should refrain from playing hockey and other vigorous sports. And make sure you have your kids vaccinated against H1N1 just as soon as the vaccine becomes available.

For a balanced perspective that puts Evan's death into context, read Andre Picard's article in the Globe and Mail.