Many, many hours of exposure are needed to spread a disease, rare for Nova Scotia, recently confirmed at a local daycare.
That is according to Dr. Ryan Sommers, Senior Regional Medical Officer with Nova Scotia Health.
The facility remains unnamed but was in the province’s Central Zone which includes Halifax, the Eastern Shore and West Hants.
The exposure was between April and July; however, Nova Scotia Health says the risk to the general public is low.
Hard to catch
Sommers tells us tuberculosis (TB) is uncommon in our province with only 12-18 cases confirmed every year and only about 1,200 in Canada; a long way from when TB was the leading cause of death in the first half of the 20th century.
It’s an infectious disease caused by bacteria that often invades the lungs, spread mainly through droplets when someone coughs- but it is not spread as easily as the common cold, flu, measles or COVID-19.
You really need prolonged, multiple exposures to get infected, and the vast majority who are, Sommers says, don’t get any symptoms at all.
“About 95 per cent of the time, people don’t get sick. For some reason a small number of bacteria can remain inactive in your lungs, and they can remain there for many years, sometimes decades. That bacteria can reactivate sometime in the future, in some people.”
What triggers this is not entirely clear, but Sommers says it can be from other diseases like diabetes or cancer.
He says only about 5 per cent of people who have been exposed to an active TB case will develop symptoms.
“That will include things such as a long-lasting cough, that’s more than 2-3 weeks long, they get a fever, then you get night sweats, then you get swollen lymph nodes, and they can also have significant weight loss as well.”
He adds that the majority of cases Public Health deals with is when someone was born or lived in a different country that had more cases and picked it up at some point in their life.
Treatable
TB is treatable with antibiotics.
However, Sommers says if it gets into the deep tissue in the lungs, it can take several months to heal.
A vaccination is also available, but usually given to those at a higher risk.
In an email to our newsroom Public Health says they are working directly with all contacts of the recent case.