About 5000 people from throughout the North Island attended the national event.
Dr McElnay said measles was highly infectious and could be caught just by sharing the same air with someone who was infected with the disease.
"So far I've not been alerted to anyone in Hawke's Bay who has measles symptoms after being at the festival, but the disease can take 14 days before symptoms develop."
Anyone who attended the concert and wasn't sure of their immunisation status should check with their family doctor, she said.
"If you or your family have any of the early symptoms of the measles - such as fever, runny nose, sore, runny eyes and cough - should phone their doctor for advice."
She said it was crucial that anyone worried they had measles or symptoms did not just turn up at the doctors or an emergency department. They should phone ahead so people in waiting rooms did not also become infected.
Hawke's Bay Today understands that some Hawke's Bay locals did attend the event.
A Ngati Kahungunu Iwi Inc spokeswoman refused to comment.
Measles is highly infectious. It is a vaccine-preventable disease and anyone who has had at least two doses of the Measles, Mumps and Rubella (MMR) vaccination is considered immune.
If you or your child are not immune, as a precaution you should stay at home for 14 days after the event in isolation/quarantine until April 30.
If you are unsure if you are immune or not, please call your GP to check your or your child's records.
People can also call Healthline on 0800 611 116 for advice.
