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. Alghamdi, A, Hempel, A, Heendeniya, A, Clifford-Rashotte, M, Tan, DHS, Bogoch, II et al.. HIV post-exposure prophylaxis-in-pocket ("PIP"): long-term follow-up of individuals with low-frequency, high-risk HIV exposures. AIDS. 2019; :. doi: 10.1097/QAD.0000000000002441. PubMed PMID:31764075 .
  2. Wang, L, Moqueet, N, Lambert, G, Grace, D, Rodrigues, R, Cox, J et al.. Population-Level Sexual Mixing By HIV Status and Pre-exposure Prophylaxis Use Among Men Who Have Sex with Men in Montreal, Canada: Implications for HIV Prevention. Am. J. Epidemiol. 2019; :. doi: 10.1093/aje/kwz231. PubMed PMID:31612213 .
  3. Tan, DHS, Rolon, MJ, Figueroa, MI, Sued, O, Gun, A, Kaul, R et al.. Inflammatory biomarker levels over 48 weeks with dual vs triple lopinavir/ritonavir-based therapy: Substudy of a randomized trial. PLoS ONE. 2019;14 (9):e0221653. doi: 10.1371/journal.pone.0221653. PubMed PMID:31490959 PubMed Central PMC6730918.
  4. Walmsley, B, Gallant, D, Naccarato, M, Hull, M, Smith, A, Tan, DH et al.. The PrEP You Want: A Web-Based Survey of Online Cross-Border Shopping for HIV Prophylaxis Medications. J. Med. Internet Res. 2019;21 (7):e12076. doi: 10.2196/12076. PubMed PMID:31333200 PubMed Central PMC6681640.
  5. Burchell, AN, Lisk, R, Yeung, A, Rana, J, Bacon, J, Brunetta, J et al.. Community-Directed Bacterial Sexually Transmitted Infection Testing Interventions Among Men Who Have Sex With Men: Protocol for an E-Delphi Study in Toronto, Canada. JMIR Res Protoc. 2019;8 (7):e13801. doi: 10.2196/13801. PubMed PMID:31274111 PubMed Central PMC6637728.
  6. Hughes, C, Yoong, D, Giguère, P, Hull, M, Tan, DHS. Canadian guideline on HIV preexposure prophylaxis and nonoccupational postexposure prophylaxis for pharmacists. Can Pharm J (Ott). ;152 (2):81-91. doi: 10.1177/1715163519826171. PubMed PMID:30886661 PubMed Central PMC6410427.
  7. Chan Carusone, S, Guta, A, Robinson, S, Tan, DH, Cooper, C, O'Leary, B et al.. "Maybe if I stop the drugs, then maybe they'd care?"-hospital care experiences of people who use drugs. Harm Reduct J. 2019;16 (1):16. doi: 10.1186/s12954-019-0285-7. PubMed PMID:30760261 PubMed Central PMC6373073.
  8. Grewal, R, Allen, VG, Bayoumi, AM, Gardner, SL, Kaul, R, Mazzulli, T et al.. Brief Report: Syphilis Coinfection Is Not Associated With an Increased Risk of Virologic Failure Among HIV-Positive Men Who Have Sex With Men on Antiretroviral Therapy. J. Acquir. Immune Defic. Syndr. 2019;80 (5):585-589. doi: 10.1097/QAI.0000000000001962. PubMed PMID:30730358 .
  9. 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 PubMed Central PMC6287974.
  10. O'Donnell, S, Tan, DHS, Hull, MW. New Canadian guideline provides evidence-based approach to non-occupational HIV prophylaxis. CJEM. 2019;21 (1):21-25. doi: 10.1017/cem.2018.462. PubMed PMID:30457087 .
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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