Teams from Alberta Precision Laboratory and the University of Alberta have discovered that a rare pulmonary disease linked to bats and birds has made its home in Alberta.
Histoplasmosis is a fungal infection transmitted through bat and bird droppings that can be present in contaminated dust particles.
When inhaled, patients experience respiratory infections with flu-like symptoms like cough, fever, chills and headache.
Histoplasmosis has always been a travel-related disease, according to a Thursday news release from Alberta Health Services, and cases are usually related to people who have come into contact with droppings in old homes, churches, construction sites and parks.
“So proximity to construction sites or in people’s homes, older homes, if they were doing construction, or even cleaning out old churches, is some of the areas where exposures occurred,” said Tanis Dingle, APL’s lead clinical microbiologist for fungal diseases and an assistant professor in the U of A’s faculty of medicine and dentistry.
There were 45 cases confirmed in Alberta between 2011 and 2018.
“We were surprised at how many cases were locally acquired, as histoplasmosis has always been considered a travel-related infection,” Dingle said.
“We now know that it is definitely living in Alberta and has the potential to infect people who come in contact with it.”
The team at APL and the U of A started looking into whether the disease was being transmitted in Alberta when they realized positive cases had started to be confirmed in the lab that didn’t have any connection to travel.
The researchers used epidemiologic data and genetic analysis of the confirmed cases in Alberta to determine 15 of them were locally acquired.
The cases were primarily in rural Alberta including Sundre, Stettler and county, Stony Plain and Spruce Grove.
The disease is usually found in the central United States and parts of southern Ontario and Quebec. Until now, the geographic range of the disease was not thought to be further northwest than Minnesota.
According to Dingle, its not that cases are on the rise in Alberta, it’s maybe cases weren’t detectable before or they hadn’t realized they were infected in Alberta.
“We aren’t seeing a trend or an increase just based on the seven years we looked at, but what people should know is it’s still a very rare infection, so it’s unlikely to be acquired by people in Alberta unless they are doing some of the high-risk activities.”
According to the team, this discovery is also important because histoplasmosis can be hard to diagnose and doctors would likely rule it out if the patient didn’t have travel history.
“Knowing that histoplasmosis is here can help improve the diagnosis and treatment of patients who have no history of travel to the traditional risk areas,” said Ilan Schwartz, assistant professor, division of infectious diseases at U of A.
“Histoplasmosis can be a challenging disease to diagnose and to treat, and patients often spend months before the correct diagnosis is made.
“Awareness that the disease is here is an essential first step for doctors to be able to consider the diagnosis and order the appropriate tests.”
Researchers aren’t sure what has driven the disease further north, but are exploring climate change as a possible factor. Increasing temperature and precipitation have been recorded in Alberta over the past several decades and could possibly have created more favourable conditions for histoplasma to live in Alberta soils.