Whooping cough outbreaks persist in Alberta as health officials urge vaccination

As pertussis cases continue to climb, Albertans are being warned to ensure their children are up-todate on their immuniza‐ tions.

The highly contagious bacterial infection, common‐ ly known as "whooping cough," can impact people of all ages, but babies are at the highest risk.

Between Jan.1 and Feb. 21 of this year, 78 cases were identified.

There were 884 lab-con‐ firmed cases in Alberta in 2023, making it the second worst year for whooping cough in the past decade.

The latest surge began when cases started appear‐ ing in southern Alberta last year. An outbreak was offi‐ cially declared in the south zone in January 2023. Whooping cough eventually spread around the province.

Data provided by Alberta Health Services (AHS) shows 966 cases were reported be‐ tween November 2022 and Feb. 21, 2024. Here is a breakdown by zone:

South zone - 452. Central zone - 68. Calgary zone - 42. Edmonton zone - 39. North zone - 365.

According to AHS, there were 29 hospitalizations dur‐ ing this time period. No deaths were reported.

In a recent public service announcement, AHS cau‐ tioned that case are rising.

"Routine immunizations are more important than ever. Cases of pertussis have increased in Alberta in the last few months and have been identified in all AHS zones," the statement said, noting infants are at the greatest risk of complica‐ tions.

The most recent outbreak was declared Feb. 2 in the Edmonton zone, where there have been four cases, ac‐ cording to AHS.

"I think it speaks to a broader decline in vaccine uptake leading to the reemergence of different vac‐ cine-preventable diseases," said Dr. Jia Hu, a Calgarybased public health physician who teaches at the University of Calgary.

This comes at a time when measles outbreaks are sparking concerns globally and travel-related cases are being identified in Canada.

Pertussis is often called the 100-day cough because the distinctive cough that comes along with it can last for months

According to AHS, it starts with a runny nose, sneezing, fever and mild cough.

The cough eventually be‐ comes more severe and, in younger children, coughing fits are often followed by a "whooping" sound as they in‐ hale. These spells can be punctuated by vommitting.

Pertussis can lead to pneumonia and, in rare cases, it can result in brain in‐ jury, seizures or even death.

Vaccine recommenda‐ tions

Alberta's routine child‐ hood immunization schedule recommends babies receive their first dose of the vaccine that protects against pertus‐ sis (dTAP) at two months of age, with further doses at four, six and 18 months.

Boosters are also sup‐ posed to be given when chil‐ dren are four years old and again in Grade 9.

The percentage of Alberta children up-to-date with the pertussis vaccine by age 2 dropped to 71 per cent in 2022, down from 78 per cent in 2008. In the north and south zones, rates have dropped below 60 per cent, with some areas reporting much lower vaccination rates.

"Usually there's a big drop off for that fourth dose, and so I think it's really important that people stay up-to-date with their recommended rou‐ tine vaccinations," said Hu.

Provincial data shows 91 per cent of two-year-olds have one dose of the vaccine, compared with the 71 per cent who have all four doses.

"We're most worried about pertussis in very young kids - you know, less than one year of age, sometimes less than that - because they have less immunity to per‐ tussis and are more likely to be hospitalized for it," said Hu.

According to the AHS website, whooping cough causes between one and four deaths in Canada each year.

"These deaths are most often in babies who are too young to be immunized or children who are not fully im‐ munized," it states.

Pregnant Albertans should also be immunized against pertussis, according to Hu, because they pass along antibodies that help protect their newborns when they're too young to be im‐ munized.

The National Advisory Committee on Immunization recommends the shot be of‐ fered during each pregnancy, ideally between 27 and 32 weeks gestation.

In addition, the province recommends all adults get boosted every 10 years.

Pertussis can be treated with antibiotics.

AHS said people who test positive for pertussis should stay home until five days of antibiotic treatment have been completed. Alterna‐ tively, people should stay home until three weeks after their cough starts or until the cough ends, whichever comes first.