Measles & Rubella Weekly Monitoring Report – Week 18: April 28 to May 4, 2024

Organization: Public Health Agency of Canada
Date published: 2024-05-16

Key points:

In Canada, 6 new cases of measles and no new cases of rubella were reported in week 18, 2024.
Currently, there are 41 active^{Footnote 1} cases of measles in Canada.
75 cases of measles and 1 case of congenital rubella syndrome/infection have been reported in Canada in 2024.
Canadians travelling outside of Canada are encouraged to consult the travel health notices for information on measles and rubella outbreaks occurring in other countries.

Epidemiological summary

During epidemiological week 18, 2024, 6 new cases of measles and no new cases of rubella were reported in Canada^{Footnote 2}. 1 case was reported by the province of Quebec. Rash onset occurred in epidemiological week 18.

5 cases were reported by the province of Ontario: 1 case was travel-related with recent travel to Egypt, and 4 cases were epidemiologically linked to a travel-related case. Of these 5 cases, 3 were children and 2 were adults. 4 cases were unvaccinated, and 1 case had an unknown vaccination status. All cases had rash onset (or prodrome onset where rash onset was unknown for 2 cases) in epidemiological weeks 17 or 18.

To date in 2024, 75 cases of measles and 1 case of congenital rubella syndrome/infection have been reported. The last case of rubella was reported in September 2023.

Figure 1. Text version below. — Figure 1: Number of cases of measles (n=75), rubella (n=0), and congenital rubella syndrome/infection (n=1)^{Footnote 3} by week of rash onset, as reported to the Canadian Measles/Rubella Surveillance System (CMRSS) and Measles and Rubella Surveillance System (MARS), for the period ending May 4, 2024.

Epidemiological Week of Rash Onset, 2024	Number of confirmed measles cases reported	Number of confirmed congenital rubella syndrome/infection cases reported
1	0	0
2	1	0
3	1	0
4	0	0
5	1	0
6	1	1
7	3	0
8	3	0
9	10	0
10	6	0
11	8	0
12	6	0
13	7	0
14	7	0
15	4	0
16	7	0
17	6	0
18	4	0
19	0	0
20	0	0
21	0	0
22	0	0
23	0	0
24	0	0
25	0	0
26	0	0
27	0	0
28	0	0
29	0	0
30	0	0
31	0	0
32	0	0
33	0	0
34	0	0
35	0	0
36	0	0
37	0	0
38	0	0
39	0	0
40	0	0
41	0	0
42	0	0
43	0	0
44	0	0
45	0	0
46	0	0
47	0	0
48	0	0
49	0	0
50	0	0
51	0	0
52	0	0
Cases (year-to-date)	75	1

Geographic distribution

There are currently 41 active^{Footnote *} cases of measles in Canada.

Figure 2. Text version below. — **Figure 2. Distribution of active^{Footnote *}, confirmed measles cases by health region.**

Health Region	Measles Active Cases
Eastern Regional Integrated Health Authority	0
Central Regional Integrated Health Authority	0
Western Regional Integrated Health Authority	0
Labrador-Grenfell Regional Integrated Health Authority	0
Prince Edward Island	0
South Shore District Health Authority	0
South West Nova District Health Authority	0
Annapolis Valley District Health Authority	0
Colchester East Hants Health Authority	0
Cumberland Health Authority	0
Pictou County Health Authority	0
Guysborough Antigonish Strait Health Authority	0
Cape Breton District Health Authority	0
Capital District Health Authority	0
Zone 1 (NB)	0
Zone 2 (NB)	0
Zone 3 (NB)	0
Zone 4 (NB)	0
Zone 5 (NB)	0
Zone 6 (NB)	0
Zone 7 (NB)	0
Québec et Chaudières-Appalaches	0
Centre-du-Québec	5
Montréal et Laval	8
Ouest-du-Québec	2
Montérégie	12
Nord-Est	0
Ontario Central East	1
Ontario Central West	8
Ontario Eastern	0
Ontario North East	0
Ontario North West	0
Ontario South West	0
City of Toronto Health Unit	4
Winnipeg Regional Health Authority	0
Prairie Mountain Health	0
Interlake-Eastern Regional Health Authority	0
Northern Regional Health Authority	0
Southern Health	0
Saskatchewan South	0
Saskatchewan Central	0
Saskatchewan North	0
South Zone	0
Calgary Zone	0
Central Zone	0
Edmonton Zone	1
North Zone	0
British Columbia	0
Yukon	0
Northwest Territories	0
Nunavut	0

Footnote *

Active measles cases are those in which the onset date of the case falls within 42 days of the end date of the epidemiological week of the report. The Centers for Disease Control and Prevention. Manual for the Surveillance of Vaccine-Preventable Diseases. Chapter 7: Measles. https://www.cdc.gov/vaccines/pubs/surv-manual/chpt07-measles.html. Page last reviewed: May 13, 2019.
Active rubella cases are those in which the onset date of the case falls within 46 days of the end date of the epidemiological week of the report. The Centers for Disease Control and Prevention. Manual for the Surveillance of Vaccine-Preventable Diseases. Chapter 14: Rubella. https://www.cdc.gov/vaccines/pubs/surv-manual/chpt14-rubella.html. Page last reviewed: May 18, 2018.

Return to footnote * referrer

Laboratory summary

Measles

During epidemiological week 18, 2024, the measles genotype was identified for 2 cases that were reported in epidemiological week 16. The 2 cases were reported in Quebec: 1 case was epidemiologically linked to a travel-related case (genotype B3), and the other was an imported case with recent travel outside of Canada (genotype B3).

To date in 2024, 56 cases of measles have been genotyped; 47 were B3 and 9 were D8.

Figure 3. Text version below. — **Figure 3: Distribution of measles genotypes detected in 2024 (n=56) by week^{Footnote †} of rash onset.**

Epi week	B3	D8	Total
1	0	0	0
2	0	1	1
3	0	1	1
4	0	0	0
5	1	0	1
6	1	0	1
7	2	0	2
8	2	1	3
9	9	1	10
10	3	2	5
11	6	1	7
12	4	0	4
13	6	1	7
14	6	0	6
15	2	1	3
16	4	0	4
17	1	0	1
18	0	0	0
19	0	0	0
20	0	0	0
21	0	0	0
22	0	0	0
23	0	0	0
24	0	0	0
25	0	0	0
26	0	0	0
27	0	0	0
28	0	0	0
29	0	0	0
30	0	0	0
31	0	0	0
32	0	0	0
33	0	0	0
34	0	0	0
35	0	0	0
36	0	0	0
37	0	0	0
38	0	0	0
39	0	0	0
40	0	0	0
41	0	0	0
42	0	0	0
43	0	0	0
44	0	0	0
45	0	0	0
46	0	0	0
47	0	0	0
48	0	0	0
49	0	0	0
50	0	0	0
51	0	0	0
52	0	0	0
Total	47	9	56

Footnote †

Epidemiological weeks for laboratory specimens submitted to the National Microbiology Laboratory are assigned and reported in accordance with WHO guidelines (WHO.WER.2012;9(87):73) with week 1 beginning on the first Monday of the year, which for 2024 is January 1. However, for the purposes of this report, the genotype data is presented in accordance with PAHO reporting weeks with week 1 of 2024 beginning on December 31, 2023.

For information regarding the interpretation and use of measles genotyping (including a discussion of genotypes and named strains), refer to Hiebert J and Severini A. Canada Communicable Disease Report. 2014; 40-12: 257- 260. URL : https://www.canada.ca/fr/sante-publique/services/rapports-publications/releve-maladies-transmissibles-canada-rmtc/numero-mensuel/2014-40/rmtc-volume-40-12-12-juin-2014/rmtc-volume-40-12-12-juin-2014-1.html

The current global distribution of measles genotypes can be found on the WHO Measles Surveillance website. URL: https://www.who.int/teams/immunization-vaccines-and-biologicals/immunization-analysis-and-insights/surveillance/monitoring/provisional-monthly-measles-and-rubella-data

Return to footnote † referrer

Footnotes

Footnote 1

Active measles cases are those in which the onset date of the case falls within 42 days of the end date of the epidemiological week of the report. Active rubella cases are those in which the onset date of the case falls within 46 days of the end date of the epidemiological week of the report.

Return to footnote 1 referrer

Footnote 2

Only cases with rash onset up to the indicated end date are included in this report. Any additional cases will be described in future reports.

Return to footnote 2 referrer

Footnote 3

Epidemiological week of birth is used for congenital rubella syndrome/infection cases.

Return to footnote 3 referrer

Page details

Date modified:: 2024-05-17

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