Hospitals warn about rare infection emerging in Calgary

Alberta health officials are noticing the spread of a rare bacteria called Haemophilus influenzae type b (Hib) among homeless adults living in Calgary.

A memo to emergency departments and urgent care personnel in primary and preventive health services obtained by CBC News warns of a “cluster of aggressive Hib cases caused by a genetically distinct sequence type.”

“This strain was first reported in British Columbia and is now appearing among adults experiencing homelessness or unstable housing in our region,” the memo reads.

In 2022, An outbreak of Hib was reported on Vancouver Island.There is also a spread among the homeless population as well as among people who use drugs. Island Health said at the time that one person had died from the infection.

According to the Alberta government, eight cases of Hib have been reported in the Calgary area in 2025. This compares with three cases in 2024 and two cases between 2019 and 2023.

Dr. Isaac Bogoch, an infectious disease specialist at Toronto General Hospital, says Hib used to cause much illness in children until a vaccine was discovered and it was included as part of routine childhood vaccinations.

,“It’s not a very common infection, but I think if you work in a hospital, you wouldn’t be surprised to see it occasionally,” Bogoch said.

“Is this going to put significant pressure on anyone? already expanded healthcare systemno it’s not. “But it’s important to recognize that patients who come in with risk factors, such as homelessness, may be at risk for this infection.”

The memo acknowledges that Hib is relatively rare in Calgary, but requires awareness of the “epidemiological specificity of the strain.”

Hib symptoms

Despite the similarity in their names, Hib is not related to the influenza virus (and it is a bacteria, not a virus.)

However it can manifest as flu-like symptoms, such as ear or sinus infections. Health Canada says In rare, more severe cases, Hib can enter the blood and infect various organs. It can then cause symptoms such as fever, drowsiness and vomiting and can be fatal.

Bogoch says that as the infection progresses, it is not difficult to treat, diagnose or prevent it, but said it is “This is an infection that is more common in the homeless population.”

He says this is due to the lack of infrastructure in an environment where people congregate together and have less access to health care and sanitation services.

Those factors may increase the risk of weakened immune systems among the homeless population, making them more vulnerable to spreading infection, said Dr. Monty Ghosh, an addiction and internal medicine specialist and assistant professor at the University of Calgary and the University of Alberta.

The bacteria usually spreads through coughing, sneezing or sharing things like utensils or cups.

A memo from Alberta’s Ministry of Primary and Preventive Health Services said surveillance for Hib has been increased, and contact tracing will be conducted.