Hamilton has 12 confirmed cases of mumps - three of the cases are Waikato University students who were exposed to an infected person at the same location on Hood Street last month.
Eleven of the cases got sick within a week of one-another.
“These are significant numbers," said Dr Richard Hoskins in a statement from the Waikato DHB.
“Almost all were at the same location during the time they would have been exposed.
“If you get symptoms that might be measles or mumps please don’t spread it - no one wants these serious diseases in the run up to Christmas.”
You can get mumps up to three and a half weeks after being in contact with an infected person.
There have been 34 confirmed cases of measles in Waikato since August 1.
Mumps is spread through fluid from the mouth or nose of the infected person.
The symptoms of mumps include a headache, fever and swollen glands.
"If you get swollen tender cheeks, you need to be in isolation at home for five days after the symptoms start," said Dr Hoskins.
The best protection against mumps is getting the measles, mumps and rubella (MMR) vaccine, he said.
Visit your doctor if you think you have mumps or call Healthline on 0800 611 116.