The respiratory virus known as RSV has become a notifiable disease under the Public Health Act on P.E.I.
The province's Chief Public Health Officer, Dr. Heather Morrison, says respiratory syncytial (pronounced sin-SISH-ul) virus is a common childhood illness that usually crops up in late fall and early spring.
RSV usually causes mild, cold-like symptoms, but can be more serious for infants and older adults.
Mpox and the tick-borne diseases anaplasmosis and babesiosis were also added to the province's mandatory reporting list, with the regulation making that official having come into effect on May 13.
Morrison said adding these diseases to the list of more than 70 notifiable diseases on P.E.I. is a way to strengthen the surveillance and public health response to them.
For RSV in particular, she said there are several promising vaccines in development for both infants and older adults, so provinces and territories are gathering as much information as they can about its prevalence.
"With these vaccines coming on board ... P.E.I. really needs good data in terms of monitoring effectiveness of any future vaccines. And it's really important as we're tracking all our respiratory illnesses, so that we can make sure we're getting a good handle on RSV, influenza and COVID," she said.
"With mandatory reporting, we can make sure we get better data, more information about the age ranges with the RSV detections we're getting. For instance, are we getting more detection in those who are 65 years of age and older?
"[It] helps with that overall surveillance and also can give us the baseline information if we introduce a vaccine in the future."
Morrison used the example of a vaccine that was introduced for rotavirus.
"It decreased our [hospital] admissions of children less than five due to rotavirus by over 90 per cent within one year. So it was really important to have that kind of surveillance data around rotavirus for the years… prior to the introduction of that vaccine," she said.
Morrison said physicians and nurse practitioners, not patients themselves, will be required to report cases of RSV and the other three newly reportable diseases.
"I don't think there's going to be a significant difference except that it makes it more official, because a lot of this information we were already having to get… But it gives us better information about those detections that we have.
"How many RSV detections that we're having year over year wasn't being done officially and now we want to make sure that's happening."
Morrison said most children will experience RSV infections by the age of two, but re-infection with the virus can occur at all ages.
"I think we have been conscious of RSV for a long time ... I do think with COVID there's a lot of interest and focus on respiratory infections in general. So I think we're paying more attention to it," she said.
We've had 384 RSV detections in P.E.I. since the end of August. — Dr. Heather Morrison
"In P.E.I. we've had three RSV outbreaks this season and these outbreaks of RSV of course are reportable under our regulations. We've had 384 RSV detections in P.E.I. since the end of August."
And that likely doesn't tell the whole story. Like influenza, Morrison said, lab-confirmed RSV detections are just an indication of greater activity in the community, since many people with RSV do not seek medical attention or get tested.