The person was present at locations in 108 Mile Ranch and Lone Butte between March 1 and March 3, including Tim Hortons, Spruce Hill Resort, and Interlakes Regional Library.
IH says the risk to the general public is considered low. "Measles is a serious and highly contagious disease that can spread quickly".
"Unimmunized people who come within two meters (6.56 ft) of an infectious person, however briefly, have a 90-percent chance of contracting measles", the Board said.
In Kamloops, Kamloops Health Centre, 519 Columbia St., is open Monday, Wednesday, Thursday and Friday from 8 a.m.to 4 p.m. and on Tuesday from 8:30 a.m.to 6 p.m.
"It can now be assumed that measles is circulating widely in our community", the Canterbury District Health Board said in a statement.
If you think you may have the disease, call your local healthcare provider or local hospital or urgent care to set up a time to visit the office as to not expose the illness to others. This will allow the office or hospital to make a plan to prevent other people from potential exposure.
A public health nurse will review your vaccine history, determine your immunity to measles, and arrange for post-exposure prophylaxis if eligible.
It said the best protection from the disease was for people to have two doses (measles, mumps and rubella) vaccinations.
Vaccines are free at community health centres. For adults and kids over five a pharmacist may also have the vaccine available.
Complications from measles can include pneumonia, inflammation of the brain, seizures, deafness, brain damage, and death.
According to the World Health Organisation, the first sign of measles is usually a high fever, which begins about 10 to 12 days after exposure to the virus. If you have any concerns about what you see in comments, email the editor in the link above.