Don't use rapid tests to rule out strep throat, many pharmacists directed

In Nova Scotia — one of the three provinces where in-pharmacy strep tests are available — the College of Pharmacists says it agrees with infectious disease specialists that the rapid tests shouldn't be used to diagnose strep throat, especially in children.

Nova Scotia College of Pharmacists says tests don't meet standard of care to diagnose strep in kids

Rapid antigen tests to detect strep bacteria should not be used on their own to rule out strep throat in children, according to widely accepted pediatric infectious disease guidelines. (Fancy Studio/Shutterstock)

As efforts to bring $15 rapid strep tests to Canada's pharmacies continue, the Nova Scotia College of Pharmacists says using them in the absence of a consultation with a physician or nurse practitioner does not meet the "standard of care" for diagnosing strep throat, especially in children. 

The Neighbourhood Pharmacy Association of Canada, a national association representing pharmacy business owners, says the rapid tests can help save patients with sore throats a trip to the doctor's office and reduce unnecessary antibiotic prescriptions. That's because many sore throats are caused by viruses, not bacteria, rendering antibiotics useless. 

The association's members include Shoppers Drug Mart, which started providing the tests about three years ago through pilot projects in the three provinces: Nova Scotia, Alberta and British Columbia.

For the rapid tests, pharmacists take a throat swab and test for Group A streptococcus bacteria (which cause strep throat) on site within minutes. If it comes back positive for strep, they advise the patient to go see a doctor or nurse practitioner for an antibiotic prescription.

If the test comes back negative, the association says, the patient may be able to just go home and rest instead of braving crowded waiting rooms. 

But many pediatric infectious disease specialists say the in-pharmacy tests aren't accurate enough to rule out strep throat on their own — and it's risky to miss strep diagnoses in children, because they can suffer from complications.

The Nova Scotia College of Pharmacists shares that concern. In May, it instructed pharmacists in that province to stop doing the rapid strep tests for diagnosis.  

'It needed to stop'

Rapid strep tests seemed like a good idea when they first arrived, said Beverley Zwicker, registrar of the Nova Scotia College of Pharmacists.

Pharmacists "really saw this as providing a service to people," she told CBC News. 

But as the tests became more widely available, the college began hearing concerns from children's health-care providers. They included reports of pediatric patients showing up at a Halifax emergency department with positive strep tests from local pharmacies when they didn't actually have strep throat, Zwicker said.

When the college looked into the issue further, it determined that having a pharmacist swab a child's throat to test for strep without a complete medical examination was contrary to the clinical practice guidelines established by the Infectious Diseases Society of America, which are regularly used by health-care providers in Canada. 

Those guidelines say that for children, even a negative rapid strep test should be backed up by a throat "culture" test — which definitively confirms the presence of strep by seeing if it grows in a lab setting from the throat sample. That's the test doctors routinely use when they suspect strep throat in kids.

So in May, the college "made it very clear to all pharmacists that conducting this test without the patient first having that physical assessment by a physician or nurse practitioner was inappropriate and that it needed to stop," Zwicker said.  

The Nova Scotia College of Pharmacists issued this notice in May 2018. (Nova Scotia College of Pharmacists)

The point-of-care tests may still have a role to play if pharmacists work in conjunction with doctors and nurse practitioners, she said.

If a doctor examines a patient and believes they have strep throat, for example, they can send the patient to the pharmacy with an antibiotic prescription contingent on the result of the point-of-care test. If it's positive, the patient can start antibiotics right away, instead of waiting for the results of a traditional "throat culture test," which is sent to a lab and takes a couple of days.

It's too early to tell whether doctors and nurse practitioners will use that option, Zwicker said, since the strep throat "season" has just begun.  

Pharmacists do 'thorough assessment,' association says

When asked to respond to the concerns expressed by the Nova Scotia College of Pharmacists, the Neighbourhood Pharmacy Association said it agreed "that an assessment of symptoms by a healthcare provider is required prior to determining the appropriateness of the point of care testing" and that pharmacists have "the training and the expertise" required. 

"Pharmacists are healthcare providers and we do perform a thorough assessment of the patient before determining whether to perform the test," said Sandra Hanna, a practising Toronto-area pharmacist and the association's vice-president of pharmacy affairs, in an email to CBC News.   

"Like any test there are always certain limitations and pharmacists use their professional judgment when determining whether the test is appropriate for a given patient," Hanna said. 

"In some circumstances pharmacists would refer to a physician, and age is one of the criteria used in considering the appropriate care plan for a patient."

But Zwicker told CBC News that the "assessment" Nova Scotia pharmacists were asked to use in conjunction with the rapid strep tests was a questionnaire about symptoms. The college concluded that was not an adequate replacement for the examinations conducted in a doctor's or nurse practitioner's office, she said. 

New guidelines for Alberta pharmacists

In Alberta and British Columbia, the colleges governing pharmacy practice have not issued similar directives to Nova Scotia's. 

However, in an emailed statement to CBC News, Jeff Whissell, deputy registrar of the Alberta College of Pharmacy, said the college had completed new practice standards and guidelines on the use of point-of-care testing in pharmacies to take effect on Jan. 1.  

As consumer demand increases, pharmacists need to understand "the limitations" of rapid strep tests, "especially for children," he said.  

"If a rapid strep test or any other point of care test produces a negative result, pharmacists should discuss the sensitivity limitations of the test with their patient, and provide appropriate information for the patient on the need for follow-up, including the possibility of consulting with their physician for further investigation."

About the Author

Nicole Ireland

Nicole Ireland is a CBC News journalist with a special interest in health and social justice stories. Based in Toronto, she has lived and worked in Thunder Bay, Ont.; Iqaluit, Nunavut; and Beirut, Lebanon.