Alberta health officials sent out a warning Thursday to bus riders after a passenger with tuberculosis rode from Lethbridge, Alta., to Kelowna, B.C.

The ill person travelled on Greyhound bus No. 5164, which left Lethbridge for Calgary on May 24 at 10:30 a.m., and transferred to Greyhound bus No. 5155 from Calgary to Kelowna, which left at 1:30 p.m. on the same day.

Both buses picked up and dropped off passengers at various stops along the way.

The person travelled during the infectious stage of the disease.

"Public health staff are working to ensure that all Alberta contacts of the passenger in question are identified and appropriately screened. Identified contacts deemed to be at risk of infection will be tested and, if necessary, offered preventative treatment," health officials said in a statement.

"As not all bus tickets had full names or addresses, this public notification is to help ensure that those who may be at risk contact public health officials."

Anyone who was on the bus can call their local public health provider or, if they live in Alberta, can call Health Link at 1-866-408-5465.

Health officials issued a similar warning last year about a passenger who took a Greyhound bus from Merritt, B.C., to Calgary.