A game changer in HIV prevention, IHPME researcher on the use of PrEP and PEP in Canada

December 13, 2018

As of 2014, Canada has seen a slight uptick in the rate of new non-occupational HIV infections. Those in high-risk populations, including intravenous drug users, members of the LGBTQ2SIA community, and sex workers have made strides in raising awareness about the virus, but the absence of a decline in infection rates in this era, is something that Darrell Tan, assistant professor at the Institute of Health Policy, Management and Evaluation, says is a failure.

Profile of Darrell Tan
Darrell Tan, photo courtesy of St. Michael’s Hospital

“We have the tools at our disposal to end new infections in Canada,” said Tan who is also an infectious disease physician, and a scientist at the Li Ka Shing Knowledge Institute in Toronto. “What we need to be doing now is implementing these tools more broadly and working to help prevent the virus from establishing infection after exposure.”

The tools Tan refers to are known as pre and post-exposure prophylaxis, PrEP and PEP.  PEP refers to an HIV prevention strategy that emerged in the late 1990’s, and was predominantly given to those who sustained an injury while caring for someone with HIV. In the mid-2000s, PEP’s use was extended to non-occupational exposures such as sexual activity and injection drug use. The first clinical trial of PrEP was published in 2010. Yet despite these advances, an absence of information on both drugs has spurred clinicians and researchers in the field of HIV prevention, like Tan, to put together a guideline that encourages greater awareness about these game changers in the fight against HIV.

“In Canada there has been a relative absence of a strategy to scale up the use of PrEP, so we felt that by creating a guideline, we could help front-line clinicians become not only more aware of the drug, but also enable them to prescribe it safely,” said Tan.

Awareness and lack of access to the drug are some of the key barriers that prevent PrEP and PEP from proficiently being utilized. Though Ontario added PrEP to the ODB formulary in September of 2017, many patients indicate that there remain financial barriers to access. Of those in high risk populations who want to access the drug, many have found their family doctor’s unfamiliar with the drug itself and therefore unable to prescribe it readily.

The Canadian guideline illustrates for physicians that PrEP has proven to be an extremely effective strategy in reducing the rate of acquiring HIV in adults who are at a high risk of infection. The guideline also provides recommendations on the use of PrEP in populations at high risk including among men who have sex with men, heterosexual couples with an HIV positive partner, and injection drug users. PEP, which must be taken for 28 days within a 72 hour window of exposure, has also proven to be effective in reducing rates of infection.Together PEP and PrEP are part of a combined strategy for HIV prevention, one that the guideline recommends health systems to adopt and make readily available in emergency departments and sexual health clinics.

Red color ribbon awareness on young woman hand background: World aids day symbolic concept .“PrEP is not intended to be a life-long intervention,” said Tan, “but in combination with other behavioural interventions including, condoms and counselling about risk reduction, it is part of an effective prevention strategy.”

But how are individuals supposed to know whether PrEP or PEP is right for them?

Some of Tan’s research has found that even among populations where there is above average literacy about HIV, people tend to underestimate their own level of risk.

“It is not an easy question to answer,” said Tan, “Most people are aware that some behaviours can lead to a risk of HIV infection, such as sexual activity or injection drug use, but one of the biggest challenges we face, is that many people do not accurately know the HIV status of their partners.”

As a result Tan feels more needs to be done to engage the population in its own care. Destigmatizing the virus is one method, and as a health system, seeking to do a better job of actively recommending PrEP and PEP to individuals by raising awareness among the front lines of care, and by engaging the public health units and sexual health clinics across the city.

“We know what these hard risk factors are, and when we come across those, it is our duty as clinicians to make recommendations on this drug and make it available to our patients,” said Tan.

The guideline published one year ago, has been followed up by a recently published summary in the Canadian Journal of Emergency Medicine, to actively raise awareness among physicians  working in emergency medicine.

“We need to do a better job of raising awareness, that there are existing services available,” said Tan. “We are not interested in blaming people for not accessing services, as a health system, we need to do a better job of bringing those services to people.”