Deaths with unknown causes now Alberta's top killer: province

Alberta is reporting an unprecedented increase in ill-defined and unknown causes of death in 2021. 

That category is leading the way over dementia, which has been in the top spot since 2016, and COVID-19, which began adding to the death tally in the province in a big way in 2020. 

In 2021, ill-defined and unknown causes of death snagged the first spot with 3,362, up from 1,464 in 2020 and 522 the year before that, according to statistics from the Government of Alberta. 

The unknown causes of death category only began appearing on the list in 2019 — there is no record of it ranking before then, dating back to 2001. 

"I think it’s probably multifactorial, so there's probably many things playing into that," said Dr. Daniel Gregson, an associate professor in the Cumming School of Medicine at the University of Calgary, specializing in infectious diseases and microbiology. 

Gregson believes those factors include lack of resources to determine the cause of death in certain cases, delayed access to healthcare services and post-COVID complications. 

"We have this impression of surviving COVID and that’s the end of it, and that’s not necessarily true," he told CTV News. 

Gregson points to a large study out of the U.S. that found people who had COVID-19 are at a higher risk of heart disease, stroke, pulmonary embolisms and death compared to those who haven’t been infected. The risk is even higher for those who end up in hospital or the ICU with COVID. 

"We do expect that there will be deaths that aren’t directly related to COVID, but indirectly related to COVID to occur after the diagnosis in patients after the first month of infection," he said.

"One would expect that some of those patients are going to survive the COVID and then die at home from other complications." 

Alberta Health and the medical examiner’s office said they are looking into the data, but have yet to provide an explanation for the sudden spike in deaths of unknown causes. 

Dementia was the second leading cause of death in Alberta in 2021. COVID-19 took the third spot. 

COVID-19 deaths increased to 1,950 last year from 1,084 in 2020 when the pandemic began. 

"COVID still is quite high up there as we expected. Unfortunately, we haven’t been able to actually eliminate COVID deaths in the province, despite our availability of vaccines. So, that’s a bit disappointing," Gregson said. 

He said stricter restrictions in 2020 helped prevent transmission and kept case numbers low, while in 2021 cases were much higher but vaccine availability helped reduce the number of deaths. 

"I think the fact that that number is not in the top spot is essentially a medical miracle in us being able to get out vaccines in less than 18 months to the average person in Canada."

Gregson said while vaccines lower the risk of death, it's still important to be vigilant.He warns there could be another spike in COVID cases in the coming months based on what’s happening in other parts of Canada and around the world. 

Chronic ischemic heart disease was the fourth leading cause of death in the province in 2021 at 1,939. It was ranked in the top spot from 2001 to 2015. 

After that is malignant neoplasms of trachea, bronchus and lung (1,552), acute myocardial infarction (1,075), chronic obstructive pulmonary disease (1,028), diabetes mellitus (728), stroke (612) and accidental poisoning by and exposure to drugs and other substances (604).