Case Definitions for National Surveillance H1N1 Flu Virus

Current as of 2 May 2009 01:00 a.m. EDT

 

This recommendation or guideline is being provided by the Public Health Agency of Canada in response to the recent outbreak of human infections with H1N1 flu virus in North America. These documents have been developed to assist Canadian public health authorities in their surveillance activities. This advisory, recommendation or guideline is based on current available scientific evidence about this emerging disease, and is subject to review and change as new information becomes available.

Confirmed

Laboratory confirmation of H1N1 flu virus infection with or without clinical symptoms¹ by one or more of the following tests:

• RT-PCR
• Viral culture
• Four-fold rise in H1N1 flu virus specific neutralizing antibodies

Probable

Laboratory test positive for influenza A, untypeable with or without clinical symptoms ¹

 

Interim WHO guidance for the surveillance of human infection with swine influenza A (H1N1)- virus-April 29th, 2009 [available at http://www.who.int/csr/disease/swineflu/WHO_case_definitions.pdf ] requests countries to report confirmed and probable cases of H1N1 flu virus (Human Swine Flu) under IHR 2005. Canadian case definitions have been adapted to those of WHO to reflect Canada's laboratory capacity to confirm cases.