TORONTO - Parents of children with asthma should have an "increased state of alertness" about the pandemic flu virus, suggests the co-author of a new Canadian study comparing it to seasonal flu.
Asthma is a significant risk factor for kids who get the new H1N1 virus, compared to seasonal flu, the study indicates.
The work by researchers at Toronto's Hospital for Sick Children was released online Thursday by the Canadian Medical Association Journal. It is among the first publications on risk factors for children admitted to hospital with the pandemic H1N1 flu, which began circulating widely in people in the spring.
The study involved scrutinizing the charts of 58 youngsters admitted with swine flu from May 8 to July 22 this year, as well as the records of 200 kids with seasonal flu admitted from 2004 to 2009.
The data show that 22 per cent of kids admitted with H1N1 had asthma compared with six per cent of those admitted with seasonal influenza.
"Coming out of this study is the finding that children with asthma seem to be at a greater risk of ending up in hospital," said Dr. Upton Allen, chief of infectious diseases at the hospital and one of the authors of the study.
"It's a confirmation that asthma is a risk factor for severe infection due to influenza."
He said the findings should not alarm parents, but he indicated they should be vigilant.
"(Parents) should be cautious, and seek medical attention if their child who has asthma were to develop signs and symptoms suggestive of H1N1 infection," Allen said.
"There is still no reason to be alarmed, merely just an increased state of alertness with respect to the importance of H1N1 infection in children with asthma."
He said that prevention is perhaps the best strategy, and the study underscores the importance of vaccination.
Children with chronic conditions, including asthma, are among the priority groups that currently have access to the H1N1 vaccine across Canada.
Dr. Lori Whitehead, a respirologist with a fairly large pediatric component in her practice, said there have been many questions about the H1N1 flu from parents of kids with asthma.
"For any child that I believe has asthma .... even if it's mild, I'm recommending that they have the pandemic H1N1 vaccine," she said from Hamilton, where she works at the Firestone Institute for Respiratory Health at St. Joseph's Healthcare.
"The exception, of course, would be if a child had an intolerance or an allergy to egg because the vaccine is egg-based."
"Also, we do not wish to give a vaccine to a child who is currently quite ill with a fever. But otherwise there's no major contraindication and I have recommended quite strongly to the parents that they take their children for vaccination."
She finds the new research interesting, but cautions that the numbers "aren't stellar" in terms of drawing conclusions.
"I think it gives a signal that there might be an association between having asthma and developing H1N1 with complications.
"It doesn't give us cause and effect, but it creates a signal which would stimulate interest in further research."
The data also showed that children admitted to hospital with H1N1 were significantly older than those with seasonal influenza - with a median age of 6.4 years compared to 3.3 years.
In addition, the researchers found that almost half of all admissions to the intensive care unit for H1N1 influenza were children with asthma.
But Allen cautioned against extrapolating those data on ICU admissions because the sample size was fairly small.