The severity of H1N1
====================

* Nevio Cimolai

Timely information about the pandemic (H1N1) 2009 influenza would have been welcome by both the medical community and the public. Although it is expected that reports such as that from O’Riordan and colleagues 1 would eventually emerge in Canada, it was apparent to many front-line general practitioners that the patients suffering from this infection and who were returning from Mexico to Canada in April and May 2009 were not suffering an overly aggressive illness. O’Riordan’s findings are consistent with the above, but now, in the scientific eye, limitations of such research are important to recognize.

For example, it is not apparent from the paper that significant differences in age between pandemic and seasonal infection groups were to be adjusted prior to the assessment for severity of illness and outcome. Having access to early and timely data if appropriately collated and analyzed would have been of potential value to all. In future planning for potential pandemics, acquisition of such data from academic centres and public health could be speedily groomed, analyzed and disseminated. Support for such endeavours is well within the mandate of our national health agencies. We will have plenty of years ahead of influenza activity in order to give such data gathering the preliminary assessments that are required to have an excellent model well in place ahead of time.

## Footnotes

*   **For the full letter, go to:** [www.cmaj.ca/cgi/eletters/182/1/39#265037](http://www.cmaj.ca/cgi/eletters/182/1/39#265037)

## REFERENCE

1.  1. O’Riordan S, Barton M, Yau Y, et al. Risk factors and outcomes among children admitted to hospital with pandemic H1N1 influenza. CMAJ 2010;182: 39–44.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo4OiIxODIvMS8zOSI7czo0OiJhdG9tIjtzOjIyOiIvY21hai8xODIvNC8zODQuMi5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=)