# 4045
A study led by Toronto researchers at the the Hospital For Sick Children (Sickkids) has been published today in the CMAJ, the Journal of the Canadian Medical Association, that looks at pediatric hospital admission during the opening months of this pandemic.
The study examine the charts of 58 kids admitted with H1N1 between May 8th and July 22nd, and compared those against roughly 200 admissions for seasonal flu over the past 5 years.
In an average year, the hospital admits about 40 pediatric influenza patients, so the admission of 58 kids in just 10 weeks alone is illustrative that this year is different.
Among other things, the study found.
- With seasonal flu, roughly 6% of the patients admitted had a history of asthma, whereas with the novel H1N1 virus, that number was 22% (13 of 58).
- Almost half of the kids sick enough to be admitted to the ICU had a history of asthma.
- Additionally, the median age of kids admitted for H1N1 was nearly twice that of kids admitted in previous years for seasonal flu.
The study is available online.
Risk factors and outcomes among children admitted to hospital with pandemic H1N1 influenza
Sean O’Riordan MB BChir PhD, Michelle Barton MBBS DM, Yvonne Yau MD, Stanley E. Read MD PhD, Upton Allen MBBS MSc, Dat Tran MD MSc
Background: Limited data are available on disease characteristics and outcomes of children with 2009 pandemic influenza A(H1N1) virus infection (pandemic H1N1 influenza)who have required hospital admission.
Methods: We reviewed the charts of 58 children with pandemic H1N1 influenza admitted to a large pediatric hospital in Ontario, Canada, between May 8 and July 22, 2009. We compared risk factors, severity indicators and outcomes of these children with those of 200 children admitted with seasonal influenza A during the previous 5 years (2004/05 to 2008/09).
Results: Children with pandemic H1N1 influenza were significantly older than those with seasonal influenza (median age 6.4 years v. 3.3 years). Forty-six (79%) of the children with pandemic H1N1 influenza had underlying medical conditions; of the other 12 who were previously healthy, 42% were under 2 years of age.
Children admitted with pandemic H1N1 influenza were significantly more likely to have asthma than those with seasonal influenza (22% v. 6%). Two children had poorly controlled asthma, and 6 used inhaled medications only intermittently. The median length of stay in hospital was 4 days in both groups of children.
Similar proportions of children required admission to the intensive care unit (21% of those with pandemic H1N1 influenza and 14% of those with seasonal influenza) and mechanical ventilation (12% and 10%respectively). None of the children admitted with pandemic H1N1 influenza died, as compared with 1 (0.4%) of those admitted with seasonal influenza.
Interpretation: Pandemic H1N1 influenza did not appear to cause more severe disease than seasonal influenza A. Asthma appears to be a significant risk factor for severe disease, with no clear relation to severity of asthma. This finding should influence strategies for vaccination and pre-emptive antiviral therapy
