Cases of pertussis have doubled in Lethbridge region: AHS

Alberta Health Services (AHS) is expressing concern this week over an increase in confirmed cases of pertussis or whooping cough.

Whooping cough — also known by its clinical name pertussis — is a bacterial infection that may last for weeks. It can affect people of any age, but children one year of age and younger are at the greatest risk of complications including pneumonia, convulsions, brain damage and even death.

AHS declared it an official outbreak on Oct. 16 when 15 cases of whooping cough were confirmed in southern Alberta within two weeks.

Since then, more than 16 additional cases have been confirmed and more are being investigated this week, officials said.

Dr. Vivien Suttorp is lead medical officer for the south sone which includes Lethbridge, Lethbridge County and Raymond.

“The concern is that there’s a spectrum of illness,” Dr. Suttorp said.

“Some people may have mild disease, and some have very serious illness. The mild disease we don’t know about. So with 31 confirmed cases in these last few weeks, that implies there are more cases out there.”

“The number [of cases] that you see and that we talk about reflect the tip of the iceberg.”

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The outbreak has spread from the Lethbridge area out to Taber and Bow Island, officials said.

Dr. Suttorp said many people may not be aware that their immunizations are not up to date and that it’s important to check the immunization schedule guidelines.

“A majority of our cases are either not immunized or have had some immunization but aren’t up to date,” he said.

“A unique thing about whooping cough is that over time, antibodies decrease, and that happens if you’ve had disease in the past, or vaccine-induced immunity. Many people are vulnerable to this disease. It’s important to stay up to date.”

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Categorized in that vulnerable group are babies under two months of age.

Dr. Suttorp said there are options for mothers who are concerned about their infants.

“It’s very important that pregnant women are aware of the recommendation to receive a dose of the pertussis vaccine in the third trimester,” he said. “That allows the mother to build antibodies, and those antibodies will passively transfer to the baby. That baby is then protected for the first two months until it can get the vaccine.”

Tweet This Click to share quote on Twitter: "It's very important that pregnant women are aware of the recommendation to receive a dose of the pertussis vaccine in the third trimester," he said. "That allows the mother to build antibodies, and those antibodies will passively transfer to the baby. That baby is then protected for the first two months until it can get the vaccine."

Infants under two months are at the absolute most risk of severe disease, complications and death, he said.

Suttorp also stresses the importance of “herd immunity” where the majority of a group is immunized to the point of wiping out any potential cases of the disease.

“We do not see a lot of pertussis circulating in communities where the majority are immunized.”