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All quiet on the flu front in 2001
After dominating news reports last winter, influenza all but disappeared from the radar screen in January and February 2001. Statistics from Health Canada's FluWatch indicate why there is less flu around this year and the predominant strain is the B strain, which is generally associated with less severe illness. Health Canada monitors a number of indices, including reports from sentinel physicians about influenza-like illness (ILI) and submissions from laboratories. For the third week of January data from sentinel physicians indicated that of every 1000 patient visits, 27 involved cases of ILI. This was up from 22/1000 in the second week of January but much lower than last year's results of 96/1000 in the second week of January and 74/1000 in the third week. Since the start of influenza surveillance on Oct. 1, 2000, 21 642 laboratory tests have identified 1057 cases (4.8%) of influenza B and 128 cases (0.6%) of influenza A. By this time last year 32 522 tests had been performed, with 5253 (16%) being positive for influenza A and 16 (0.05%) positive for influenza B. Health Canada says the predominant strains observed to date have circulated during previous years. These strains are covered by the present vaccine. It is too early to determine what effect Ontario's $38-million program of mass influenza vaccination might have had on lessening the burden of disease relative to last year, when flu-related overcrowding of emergency departments caused a public uproar in many parts of Canada. Alison Sinclair, CMAJ
Copyright 2001 Canadian Medical Association or its licensors |