Darrell Tan


Scientist, Li Ka Shing Knowledge Institute


Dr. Darrell Tan is an infectious diseases physician, clinician-scientist and Canadian Institutes of Health Research (CIHR) New Investigator whose research focuses on clinical trials in human immunodeficiency virus (HIV) prevention and HIV/sexual transmitted infection (STI) co-infection. As Director of the University of Toronto Clinical Research Unit on HIV Prevention and co-leader of the CIHR Canadian HIV Trials Network Biomedical Prevention Working Group, he is leading multiple efforts to optimize the implementation of HIV pre- and post-exposure prophylaxis (PrEP and PEP) in Canada. These include Canada’s first demonstration project of daily oral TDF/FTC-based PrEP in Toronto MSM, the development of national Clinical Practice Guidelines on PEP & PrEP use, exploration of the relationship between syndemic health problems and clinical outcomes of PEP & PrEP, studies of nurse-led PEP & PrEP, and evaluations of novel antiretroviral PEP regimens.

Additional research interests are in the interaction between HIV and common co-infections such as herpes simplex virus type 2 (HSV-2) and syphilis, and the role of systemic inflammation in driving clinical outcomes in people living with HIV. He is also Co-Principle Investigator on two CIHR-supported multicentre randomized control trials including the a trial of anti-herpes medication for attenuating HIV disease progression, and a trial of enhanced syphilis screening in HIV-positive men.

Recent Publications

  1. Tan, DHS, Schnubb, A, Lawless, J, Szadkowski, L, Grennan, T, Wilton, J et al.. Acceptability and tolerability of and adherence to HIV preexposure prophylaxis among Toronto gay and bisexual men: a pilot study. CMAJ Open. ;6 (4):E611-E617. doi: 10.9778/cmajo.20180068. PubMed PMID:30530721 .
  2. O'Donnell, S, Tan, DHS, Hull, MW. New Canadian guideline provides evidence-based approach to non-occupational HIV prophylaxis. CJEM. 2018; :1-5. doi: 10.1017/cem.2018.462. PubMed PMID:30457087 .
  3. Salway, T, Ferlatte, O, Shoveller, J, Purdie, A, Grennan, T, Tan, DHS et al.. The Need and Desire for Mental Health and Substance Use-Related Services Among Clients of Publicly Funded Sexually Transmitted Infection Clinics in Vancouver, Canada. J Public Health Manag Pract. 2018; :. doi: 10.1097/PHH.0000000000000904. PubMed PMID:30444755 .
  4. Wang, S, Kortenaar, JL, Hull, MW, Arbess, G, Owen, JR, Tan, DH et al.. Feasibility of vitamin D supplementation interventions to mitigate HIV pre-exposure prophylaxis-related bone mineral density loss: a cross-sectional survey. Patient Prefer Adherence. 2018;12 :2197-2204. doi: 10.2147/PPA.S178403. PubMed PMID:30410315 PubMed Central PMC6199226.
  5. Tan, DHS, Raboud, JM, Szadkowski, L, Grinsztejn, B, Madruga, JV, Figueroa, MI et al.. Effect of valaciclovir on CD4 count decline in untreated HIV: an international randomized controlled trial. J. Antimicrob. Chemother. 2018; :. doi: 10.1093/jac/dky433. PubMed PMID:30376108 .
  6. Rana, J, Wilton, J, Fowler, S, Hart, TA, Bayoumi, AM, Tan, DHS et al.. Trends in the awareness, acceptability, and usage of HIV pre-exposure prophylaxis among at-risk men who have sex with men in Toronto. Can J Public Health. 2018;109 (3):342-352. doi: 10.17269/s41997-018-0064-3. PubMed PMID:29981088 PubMed Central PMC6153704.
  7. Sharma, M, Chris, A, Chan, A, Knox, DC, Wilton, J, McEwen, O et al.. Decentralizing the delivery of HIV pre-exposure prophylaxis (PrEP) through family physicians and sexual health clinic nurses: a dissemination and implementation study protocol. BMC Health Serv Res. 2018;18 (1):513. doi: 10.1186/s12913-018-3324-2. PubMed PMID:29970087 PubMed Central PMC6029110.
  8. Morrison, SA, Yoong, D, Hart, TA, MacPherson, P, Bogoch, I, Sivarajah, V et al.. High prevalence of syndemic health problems in patients seeking post-exposure prophylaxis for sexual exposures to HIV. PLoS ONE. 2018;13 (5):e0197998. doi: 10.1371/journal.pone.0197998. PubMed PMID:29791514 PubMed Central PMC5965882.
  9. Thavorn, K, Kugathasan, H, Tan, DHS, Moqueet, N, Baral, SD, Skidmore, B et al.. Economic evaluation of HIV pre-exposure prophylaxis strategies: protocol for a methodological systematic review and quantitative synthesis. Syst Rev. 2018;7 (1):47. doi: 10.1186/s13643-018-0710-0. PubMed PMID:29544530 PubMed Central PMC5855998.
  10. Wilton, J, Noor, SW, Schnubb, A, Lawless, J, Hart, TA, Grennan, T et al.. High HIV risk and syndemic burden regardless of referral source among MSM screening for a PrEP demonstration project in Toronto, Canada. BMC Public Health. 2018;18 (1):292. doi: 10.1186/s12889-018-5180-8. PubMed PMID:29486737 PubMed Central PMC5830065.
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Affiliations & Other Activities

  • Clinician-Scientist, Department of Medicine, St. Michael’s Hospital
  • Assistant Professor, Department of Medicine, University of Toronto
  • Assistant Professor, Institute of Health Policy, Management & Evaluation, University of Toronto
  • Director, HIV Prevention Clinical Research Unit, University of Toronto
  • Affiliate Scientist, Toronto General Research Institute