Whooping cough cluster reported in Yorkton, Sask.

Public health officials are warning people in Yorkton about a cluster of whooping cough cases in that city.

Whooping cough, also known as pertussis, is a contagious disease thatcan lead to severe coughing spells with a whooping sound before the next breath, and often ends in vomiting.

Since the end of Augustseven people have tested positive for the respiratory illness, and at least 12 other people who have been in contact with them also have symptoms, said Dr. MandianguNsungu, Medical Health Officer in Sunrise Health Region.

Four of the confirmed cases have been seen in the last week to 10 days, indicating the outbreak is escalating, Nsungu added.

"Maybe there are other cases out there that have not been tested, so that's why we thought that it was time maybe to inform the public," he said.

In a normal year, one or fewer cases are seen, he said.

Can be fatal for infants

The people affected range in age from 1 to 45 years, although most are adolescents, the region said in a news release.

Health officials are especiallyconcerned aboutchildren under the age of one year, for whom the disease can be fatal. Pregnant women in their last trimester can pass on the illness to their newborns.

For that reason, the health region recommends that women living, working or going to school in Yorktonwho are 26 weeks pregnant or more should get thepertussisvaccine, even if they have already been vaccinated.

"We'll continue doing that until the situation comes back to normal," Nsungu said. After that, vaccines for pregnant women in Yorkton will be limited to those who are 26 weeks or more along and have not been vaccinated since turning 18 years.

As for why this cluster is happening, Nsungu is not sure. He said clusters occur in cycles of five to seven years.

"One reason for that is if you vaccinate people, first of all the immunity that is generated by the vaccine may wane with time," he explained. Also, he added, no vaccine is 100 per cent effective, and after some years there may be a large enough pool of people to start a cluster.

Saskatchewan's health ministry said across the province, the last peak year was in 2010 with 234 reportedcases.

Currently Saskatchewan is experiencing an overall increase in cases with 80 reported cases from the start of 2015until the end of September.

Local community clusters have been reported within the past six months in some Regional Health Authorities (Sunrise, Cypress and Saskatoon).

Other recommendations for people in Sunrise Health Region:

If you have a cough that lasts two weeks or more, or any other symptoms of whooping cough (sneezing, runny nose and a fever), see a doctor or nurse practitioner.

Make sure your children's vaccinations are up to date.

Caregivers of young infants should be vaccinated.

Vaccinations can be arranged by contacting a local public health office. For a complete listing of locations and phone numbers, check hereunder Health Services/Public Health/About Public Health.