Unavailability of implicated foods for confirmation of laboratory testing at the time of outbreak investigation further complicates the matter [ 5].
To test for outbreaks of resistance to 1 antibiotic in a given species-group, profile = sensitive and profile = resistant were taken to represent 2 separate locations.
Legionellosis is a notifiable disease in Ontario, with all testing for Legionella in the context of outbreak investigation, and most testing of clinical specimens, performed at the OPHL in Toronto.
Three blood samples were taken for haemagglutination inhibition testing - at the start of outbreak, 2 weeks after completion of 10 day oseltamivir prophylaxis, and 3 weeks after the pandemic's peak in Singapore.
The isolates tested by PFGE were the first human and animal isolates to be sent to the NLEP, and testing continued until type characteristics of outbreak strains were identified and the epidemiologic designations of patients involved in the outbreak were confirmed microbiologically.
Although testing for ME is one aspect of outbreak management, identification of reliable biomarkers of exposure and toxicity could provide improved diagnostic tools during the early stages of an outbreak.
This notion was also supported by the fact that higher percentages of outbreak samples were testing positive for more than one pathogen simultaneously (60% vs. 6% of healthy samples).
But the latest testing of the most recent outbreaks, completed this week, showed that Sydney 2012 had overtaken all others to become the dominant strain.
Such outbreaks can be prevented or limited by exclusion of infected or shedding food handlers from work until 48 72 hours after recovery (25, 27, 29, 30 ), education of food handlers (26 ), and standard testing of food handlers during outbreaks (28 ).
However, we present this figure for qualitative comparisons, so that the reader can visualize the effects of baseline and outbreak temporal distribution, size, and duration on relative algorithm performance, over the range of outbreak signals we tested.
