Abstract
BackgroundIn Ontario and Canada, the incidence of human Salmonella enterica serotype Enteritidis (S. Enteritidis) infections have increased steadily during the last decade. Our study evaluated the spatial and temporal epidemiology of the major phage types (PTs) of S. Enteritidis infections to aid public health practitioners design effective prevention and control programs.MethodsData on S. Enteritidis infections between January 1, 2008 and December 31, 2009 were obtained from Ontario’s disease surveillance system. Salmonella Enteritidis infections with major phage types were classified by their annual health region-level incidence rates (IRs), monthly IRs, clinical symptoms, and exposure settings. A scan statistic was employed to detect retrospective phage type-specific spatial, temporal, and space-time clusters of S. Enteritidis infections. Space-time cluster cases’ exposure settings were evaluated to identify common exposures.Results1,336 cases were available for analysis. The six most frequently reported S. Enteritidis PTs were 8 (n = 398), 13a (n = 218), 13 (n = 198), 1 (n = 132), 5b (n = 83), and 4 (n = 76). Reported rates of S. Enteritidis infections with major phage types varied by health region and month. International travel and unknown exposure settings were the most frequently reported settings for PT 5b, 4, and 1 cases, whereas unknown exposure setting, private home, food premise, and international travel were the most frequently reported settings for PT 8, 13, and 13a cases.Diarrhea, abdominal pain, and fever were the most commonly reported clinical symptoms. A number of phage type-specific spatial, temporal, and space-time clusters were identified. Space-time clusters of PTs 1, 4, and 5b occurred mainly during the winter and spring months in the North West, North East, Eastern, Central East, and Central West regions. Space-time clusters of PTs 13 and 13a occurred at different times of the year in the Toronto region. Space-time clusters of PT 8 occurred at different times of the year in the North West and South West regions.ConclusionsPhage type-specific differences in exposure settings, and spatial-temporal clustering of S. Enteritidis infections were demonstrated that might guide public health surveillance of disease outbreaks. Our study methodology could be applied to other foodborne disease surveillance data to detect retrospective high disease rate clusters, which could aid public health authorities in developing effective prevention and control programs.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-2592-6) contains supplementary material, which is available to authorized users.
Highlights
In Ontario and Canada, the incidence of human Salmonella enterica serotype Enteritidis
Enteritidis cases were recorded in the Integrated Public Health Information System (iPHIS) database during the study period; of these, 28 cases were missing phage type information, leaving 1,336 cases (97.9 %) available for analysis
One Phage type (PT) 8 case was excluded from the scan statistics because of missing sex information
Summary
In Ontario and Canada, the incidence of human Salmonella enterica serotype Enteritidis Enteritidis) infections have increased steadily during the last decade. Salmonellosis is a major foodborne bacterial infection that continuously poses a significant human health burden worldwide [1]. In Canada, salmonellosis is the main cause of hospitalization and death among domestically acquired foodborne infections [2], causing an estimated 87,510 illnesses annually [3]. Enteritidis) became the top serovar among the non-typhoidal salmonellae in Canada [4], the United States of America (US) [5, 6], and the European Union [7]. Enteritidis phage types (PTs) among human cases are PT 8, 13a, 13, 1, 4, and 5b [4]. Between 2006 and 2010, Canadian integrated surveillance systems identified the emergence of PT 13a and an increase in the number of cases of PT 8 [4]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
