Toronto public health officials are urging up to 30 people to see a doctor after a needle was "not consistently changed" during diabetes testing at a Scarborough health fair, potentially exposing them to the viruses that cause Hepatitis and HIV.

Dr. Herveen Sachdeva, associate medical officer for Toronto Public Health, said in an email on Sunday that the city department is investigating what it is calling an "infection control breach."

But she said the potential health risk is "very low" and the letter sent to people potentially affected is a precautionary measure.

The city health agency received a complaint about the blood glucose test at the Vision Infinite Foundation's annual health fair and awareness day held at the Scarborough Village Recreation Centre on March 25.

According to its website, the non-profit organization was formed by Canadians of Bangladeshi origin to unite and build a healthy community.

'Potential health risk'

"Following a complaint that TPH received, staff immediately investigated the situation and confirmed that blood glucose testing was offered but the lancet/needle was not consistently changed between clients at the fair," Sachdeva said.

"Staff followed up with the attendees to notify them directly of the matter and potential health risk, and recommended for the individuals to follow up with a health care provider."

An event volunteer administered the blood glucose testing at the health fair, she added. The complaint was received on the same day as the event.

Getting my blood sugar tested. <a href="https://twitter.com/ShopprsDrugMart?ref_src=twsrc%5Etfw">@ShopprsDrugMart</a> <a href="https://twitter.com/hashtag/VisionInfinity?src=hash&ref_src=twsrc%5Etfw">#VisionInfinity</a> Health Fair. <a href="https://twitter.com/BEYLiberals?ref_src=twsrc%5Etfw">@BEYLiberals</a> 3600 Danforth Community Centre. <a href="https://t.co/TeDhk1gQfs">pic.twitter.com/TeDhk1gQfs</a> —@apottsmpp MPP Arthur Potts, who represents Beaches-East York, tweeted a photo of himself at the health fair. He attended the event with Mitzie Hunter, MPP for Scarborough-Guildwood.

Event organizers did not record who took the test and the number of people potentially affected is an estimate based on public health's investigation, Sachdeva said.

Officials are talking to event organizers and staff about proper procedures to test for diabetes. A lancet, or fine needle, attached to a lancing device is used during testing to draw a blood sample to be measured for blood sugar levels.

"Every medical device needs to be used and cleaned as directed by the manufacturer's instructions. Most glucometers are not designed to be reused in between people, so it is very important to follow the instructions and cleaning advice from the manufacturer," she added.

Investigation could take months

"While certain viruses carried in the blood, such as Hepatitis B, Hepatitis C, and HIV can be passed through re-use of lancets, the chances of these viruses being passed are very low."

Sachdeva said the investigation could take several months to determine if any illnesses developed as a result.

The Vision Infinite Foundation did not respond to voicemail messages for comment.

Sachdeva said infection control breaches are "extremely rare" in Toronto.

"It is unfortunate that this occurred. TPH has investigated glucometer reuse in the past and it is very important for people using glucometers to follow the manufacturer's instructions for use and to not reuse these medical devices between clients," she said.