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Epidemiological information: Outbreak of Salmonella Enteritidis

Related Public Health Notice

July 13, 2017

What is epidemiology?

Epidemiology is the study of disease in a population. Epidemiologists, or "disease detectives," use surveillance systems to identify those who are sick and confirm that the sick people are part of this event. They then gather information from the people who got sick and review the clues from all parts of the investigation that might reveal the cause of the illness event.

The figure below forms part of the epidemiological investigation into this outbreak. An "epi curve" (Figure 1) is a valuable reference tool in any epidemiological investigation. An epi curve shows when cases begin, when they peak, and when they trail off. Certain details of the people who got sick (Table 1) also help epidemiologists as they work to solve the questions involved in foodborne illness.

Figure 1. Number of people infected with Salmonella Enteritidis*

Figure 1. Number  of people infected with Salmonella Enteritidis

* Information available for 12 of 12 cases

Text equivalent for figure 1:
People confirmed to be infected with Salmonella Enteritidis by week of illness onset or specimen collection
Week of symptom onset or specimen collection Number of cases
Note: It can take several weeks from the time a person becomes ill to when this illness is reported and testing confirms a link to the outbreak.
2-Apr-2017 0
9-Apr-2017 1
16-Apr-2017 1
23-Apr-2017 3
30-Apr-2017 3
7-May-2017 0
14-May-2017 3
21-May-2017 0
28-May-2017 1

Table 1: At a Glance
Outbreak status Ongoing
Case count 12
Provinces/Territories 4
Hospitalizations 2
Deaths 0
Gender (m:f) 8:4
Age range in years 3-66
Recall Yes