Alberta has now confirmed 710 measles cases so far this year, according to new data released Monday, surpassing the 690-case mark set in 1987.
This year now marks the most cases in a calendar year since 1986, when 843 cases were reported.
The initial outbreak this year began in March and the disease has spread throughout the spring, mainly outside of the Calgary and Edmonton health zones.
The South Zone has been the hardest hit, accounting for 520 of the cases so far this year.
The Central Zone has seen 102 cases while the North Zone has seen 69.
No new cases were reported in the Calgary Zone or the Edmonton Zone over the weekend. The province’s two most populous health zones have seen a total of 19 cases so far this year, between them.
The spread of measles has occurred primarily among children and teenagers: about 29 per cent of the cases are among kids under the age of five, while 46 per cent are among those between the ages of five and 17.
Four people were in hospital with measles as of Sunday, one of whom was in intensive care.
About 10 per cent of cases with known outcomes have resulted in hospitalization so far this year. That includes about 1.5 per cent which required intensive care. No measles deaths have been reported in 2025.
Of measles cases where the patient’s immunization status is known, 91 per cent have been in individuals who never received a measles vaccine. Another five per cent were among people who had received one of the two recommended lifetime doses.
Health officials in the South Zone have said the number of confirmed cases is likely only the “tip of the iceberg” as not everyone who is infected seeks medical treatment.
Alberta Health Services issues localized exposure warnings for various communities where people with communicable measles have travelled.
It has also issued a “standing measles exposure advisory” for the entire South Zone.
“All individuals living, working, or attending school in, or travelling to, the South Zone are advised to be aware of the significant current risk for measles disease, and ensure immunizations are up to date,” the advisory reads.
“At this point, anyone in the South Zone who was born in or after 1970 and has fewer than two documented doses of measles-containing vaccine, is at risk for developing measles. They should monitor for symptoms of measles and are strongly encouraged to review their immunization records.”
