Ottawa Public Health is investigating a second case of measles in the city, after a classmate of the first child to contract the virus became ill and showed similar symptoms.

What are the symptoms of measles? Symptoms of measles may develop seven to 21 days after exposure to an infected person. Symptoms include: a high fever, runny nose, cough, drowsiness, irritability and red eyes.

Small white spots may appear in the mouth and throat.

A red blotchy rash begins to appear on the face three to seven days after the start of symptoms, then spreads down the body to the arms and legs. This rash usually lasts four to seven days. Symptoms generally last from one to two weeks. (Source: Ottawa Public Health)

Last week the public health agency said a primary student from the Stittsville school had been diagnosed with measles after returning from the Philippines. The child had not been immunized against measles.

A dozen unnimmunized students from the school were also told to stay home from class until March 18. Because of the second case, that period has been extended until March 26.

Parents can choose to not immunize their children for philosophical, religious or medical reasons.

Ottawa Public Health said secondary cases of measles are not uncommon as it is a highly contagious viral respiratory disease.

"We strongly encourage all residents to consider vaccination as a way to protect themselves and their families against measles and other vaccine-preventable diseases," the public health agency wrote in a statement Monday.

Measles can lead to ear infections, pneumonia, swelling of the brain and even death. It is more severe in adults and infants.