Related Experiment Video
Updated: Feb 28, 2026
Quantitative Analyses of all Influenza Type A Viral Hemagglutinins and Neuraminidases using Universal Antibodies in Simple Slot Blot Assays
Published on: April 4, 2011
Measles Outbreak with Unique Virus Genotyping, Ontario, Canada, 2015
Abstract:
The province of Ontario continues to experience measles virus transmissions despite the elimination of measles in Canada. We describe an unusual outbreak of measles in Ontario, Canada, in early 2015 that involved cases with a unique strain of virus and no known association among primary case-patients. A total of 18 cases of measles were reported from 4 public health units during the outbreak period (January 25-March 23, 2015); none of these cases occurred in persons who had recently traveled. Despite enhancements to case-patient interview methods and epidemiologic analyses, a source patient was not identified. However, the molecular epidemiologic analysis, which included extended sequencing, strongly suggested that all cases derived from a single importation of measles virus genotype D4. The use of timely genotype sequencing, rigorous epidemiologic investigation, and a better understanding of the gaps in surveillance are needed to maintain Ontario's measles elimination status.
Insights
Ontario experienced an unusual measles outbreak in 2015 with a unique virus strain. Molecular analysis identified a single importation event, highlighting the need for enhanced surveillance to maintain measles elimination.
Area of Science:
- Virology
- Epidemiology
- Public Health
Background:
- Canada has achieved measles elimination, yet Ontario faces ongoing measles virus transmissions.
- Maintaining measles elimination requires robust surveillance and rapid response to potential outbreaks.
Observation:
- An unusual measles outbreak occurred in Ontario in early 2015, with 18 cases across 4 public health units.
- Cases lacked recent travel history and known associations, complicating traditional contact tracing.
- A unique strain of measles virus, genotype D4, was identified in all reported cases.
Findings:
- Molecular epidemiologic analysis, including extended sequencing, strongly indicated a single importation event of measles virus genotype D4.
- Despite enhanced investigations, the primary source patient for the outbreak could not be identified.
- The outbreak demonstrated localized transmission within Ontario, independent of international travel.
Implications:
- Timely genotype sequencing is crucial for identifying the origins of measles virus transmissions.
- Rigorous epidemiologic investigations are essential for controlling outbreaks and understanding transmission dynamics.
- Addressing surveillance gaps is vital for sustaining measles elimination status in Ontario and similar regions.
