New HIV prevention guidelines from Canada released

By Dr. Ananya Mandal, MDNov 27 2017

New guidelines for Canada have been published in the Canadian Medical Association Journal online this week that outline the use of new anti-HIV medications among high risk populations who are at risk of contracting HIV from getting the dreaded infection. These new guidelines aim to provide the clinicians with resources and support he added.

This research was funded by the Canadian Institutes of Health Research and the Canadian Institutes of Health Research (CIHR) Canadian HIV Trials Network.

The guidelines outline the use of these medications both before and after exposure to HIV infection. These are called pre-exposure prophylaxis, or PrEP, and non-occupational post-exposure prophylaxis, and nPEP respectively. PrEP refers to use of antiretroviral drugs regularly before an exposure to the infection occurs.

This is suitable for persons who are at risk of getting HIV infections such as those who work with HIV positive individuals and also sexual partners of HIV positive individuals. nPEP refers to a course of anti HIV medications that are given to persons who have been exposed to HIV infection either sexually or due to drug-use related causes to prevent the infection.

The guidelines that have been released suggest that these are biomedical interventions that must be part of a combination of preventive strategies adopted for HIV prevention and control. Behavioral interventions to prevent HIV infection include use of condoms and safe sex practices and adopting other measures to protect oneself from HIV exposure.

Dr. Darrell Tan, an infectious disease physician and scientist at St. Michael's Hospital and lead author of the guidelines said in his statement, “There are new biomedical HIV prevention strategies that have been widely endorsed worldwide by organizations including the WHO, U.S. CDC and others…In particular, PrEP is a highly effective and safe Health Canada-approved method that involves taking a daily pill, which, if taken properly, can offer almost 100 per cent protection against new HIV infection.” Dr. Tan was part of the 25 member panel that worked together with the Biomedical HIV Prevention Working Group of the CIHR’s Canadian HIV Trials Network. The screened through all the available literature on the benefits provided by the PrEP and nPEP regimens.

The authors add that HIV incidence in Canada is still high and cause for concern and these guidelines come in as very important in this scenario. They write that homosexual men in Canada are 131 times more at risk of getting HIV infection compared to heterosexual men and 54 percent of the new HIV infections are seen among homosexual men. Similarly those who are injection drug users are 59 times more likely to contractHIV compared to those who are non-users. Indigenous people are 2.7 times more likely to get HIV and those who have immigrated from countries that have endemic HIV infections are 6.4 times more likely to get this infection, the report adds.

PrEP now has been recommended for:

• men who have sex with men (MSM)
• transgender women who had anal sex without a condom in the previous 6 months along with criteria such as;
  • Presence of syphilis or bacterial STD of the rectum
  • Past use of nPEP more than once
  • Ongoing relationship with a HIV positive individual
  • MSM HIV risk index (a measure for risk) over 10
• Heterosexuals who had condomless vaginal or anal sex with someone who has HIV
• Drug users who share injection paraphernalia

Drugs for PrEP include once-daily tenofovir disoproxil fumarate with emtricitabine (TDF/FTC).

The guidelines recommend nPEP in patients presenting within 72 hours of moderate or high-risk exposure to HIV. The regimens include TDF/FTC along with either raltegravir, dolutegravir or a combination of darunavir and ritonavir.

The authors performed an economic analysis assessing the cost benefit aspects of PrEP and nPEP in HIV prevention. Dr. Tan explained that the cost of these antiretroviral drugs has been the major obstacle that has “restricted the feasibility and acceptability” of these interventions. With the introduction of the generic versions of these medications and also availability of these drugs for public use, PrEP in Canada may now have a good run providing cost effective benefits. These guidelines are in the same lines as those already in place in the United Kingdom, the United States and Australia.

Dr. Tan hopes that introduction of PrEP can dramatically reduce the number of new cases as has been seen in other countries.