Also, the WHO provides more details about Sudan's first cVDPV2 case of 2022, which was confirmed in late December.
Coverage with state-required vaccines fell to 93% among kindergartners during the 2021-21 school year, down 2 percentage points from 2019-20.
The new cases are from Algeria, the Central African Republic, and the Democratic Republic of Congo.
The CDC is testing the Canadian samples to see if they are genetically related to poliovirus samples from New York.
Sudan's case is its first of the year, and genetic analysis shows it isn't related to the strain that circulated there in 2020.
Tests on samples from an index patient and 3 healthy children confirm polio transmission.
DR Congo is the only country to report more polio cases in the past week, according to the latest surveillance update.
Six African nations report more polio cases this week.
The Democratic Republic of the Congo, Indonesia, and Yemen reported polio cases.
The first locations for the expanded surveillance involve Michigan and Philadelphia.