An Ottawa mother whose daughter has a compromised immune system because of chemotherapy says she is concerned for her daughter's safety after four cases of measles were confirmed in the city.

Christy Zavitske's daughter Bridget, 7, has Wilms tumor, a type of cancer she treats in part with chemotherapy.

Though Bridget has been vaccinated against measles, chemotherapy can reduce its effectiveness and increase the severity of symptoms from a virus like measles.

With the measles present in the city and a chicken pox outbreak at her school, Zavitske has decided to keep her daughter home.

What are the symptoms of measles?

Symptoms of measles may develop 7 to 21 days after exposure to an infected person.

Christy Zavitske

Christy Zavitske said protecting her child from infectious diseases can be nerve-racking. (CBC)

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 3 to 7 days after the start of symptoms, then spreads down the body to the arms and legs. This rash usually lasts 4 to 7 days. Symptoms generally last from 1 to 2 weeks.

(source: Ottawa Public Health)

"It's a little nerve-wracking to take her out," said Zavitske. "We try to keep her at home when there's an outbreak, at the same time I don't want to isolate her. She's going through enough stuff as it is."

Ottawa’s first confirmed case of measles in three years was announced March 5 when an unimmunized child returned from the Philippines.

A classmate of the child's at St. Stephen Catholic School in Stittsville was the second confirmed case.

The third and fourth confirmed cases, an immunized adult and an unimmunized child, contracted the virus from contact with one of the previous cases.

Ottawa Public Health said the additional cases are not unexpected because virtually everyone who comes into contact with the virus and is not immune will become infected.

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

Ottawa Public Health has been encouraging people who are unimmunized to get the shot for measles, and say having the majority of the population protected against the virus can help protect those who have compromised immune systems.

"If you are not immunized then you're a sitting duck because measles is very, very infectious," said associate medical officer of health Dr. Carolyn Pim.

The city can also offer injections of immunoglobulin, which would help boost a person's own antibodies, to those who are worried they are at risk, said Pim.

"We're working through in terms of what their particular concerns are, whether their exposure was significant and whether they may benefit from the immunoglobulin," said Pim.

Zavitske said she hopes people who are choosing not to be immunized will think more about the impact it has on people like her daughter.

"I think in general people don't realize this, that they can put other children at risk even though we've chosen to immunize," she said.