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. Wilton, J, Mishra, S, Tan, DHS. Considerations for Using the HIRI-MSM Screening Tool to Identify MSM Who Would Benefit Most From PrEP. J. Acquir. Immune Defic. Syndr. 2017;76 (2):e58-e61. doi: 10.1097/QAI.0000000000001472. PubMed PMID:28903127 .
  2. Tan, DH. PrEP on demand or every day?. Lancet HIV. 2017;4 (9):e379-e380. doi: 10.1016/S2352-3018(17)30088-7. PubMed PMID:28747273 .
  3. Sivarajah, V, Venus, K, Yudin, MH, Murphy, KE, Morrison, SA, Tan, DH et al.. Does maternal HSV-2 coinfection increase mother-to-child transmission of HIV? A systematic review. Sex Transm Infect. 2017; :. doi: 10.1136/sextrans-2016-052921. PubMed PMID:28600331 .
  4. Knox, DC, Anderson, PL, Harrigan, PR, Tan, DH. Multidrug-Resistant HIV-1 Infection despite Preexposure Prophylaxis. N. Engl. J. Med. 2017;376 (5):501-502. doi: 10.1056/NEJMc1611639. PubMed PMID:28146652 .
  5. Tan, DH, Raboud, J, Szadkowski, L, Szabo, E, Hu, H, Wong, Q et al.. Novel imaging modalities for the comparison of bone microarchitecture among HIV+ patients with and without fractures: a pilot study. HIV Clin Trials. 2017;18 (1):28-38. doi: 10.1080/15284336.2016.1266074. PubMed PMID:27951753 .
  6. MacFadden, DR, Tan, DH, Mishra, S. Optimizing HIV pre-exposure prophylaxis implementation among men who have sex with men in a large urban centre: a dynamic modelling study. J Int AIDS Soc. ;19 (1):20791. . PubMed PMID:27665722 PubMed Central PMC5035769.
  7. Money, DM, Moses, E, Blitz, S, Vandriel, SM, Lipsky, N, Walmsley, SL et al.. HIV viral suppression results in higher antibody responses in HIV-positive women vaccinated with the quadrivalent human papillomavirus vaccine. Vaccine. 2016;34 (40):4799-806. doi: 10.1016/j.vaccine.2016.08.016. PubMed PMID:27544584 .
  8. Wilton, J, Kain, T, Fowler, S, Hart, TA, Grennan, T, Maxwell, J et al.. Use of an HIV-risk screening tool to identify optimal candidates for PrEP scale-up among men who have sex with men in Toronto, Canada: disconnect between objective and subjective HIV risk. J Int AIDS Soc. 2016;19 (1):20777. . PubMed PMID:27265490 PubMed Central PMC4911732.
  9. Grewal, R, Allen, VG, Gardner, S, Moravan, V, Tan, DH, Raboud, J et al.. Serosorting and recreational drug use are risk factors for diagnosis of genital infection with chlamydia and gonorrhoea among HIV-positive men who have sex with men: results from a clinical cohort in Ontario, Canada. Sex Transm Infect. 2017;93 (1):71-75. doi: 10.1136/sextrans-2015-052500. PubMed PMID:27154185 PubMed Central PMC5293859.
  10. Burchell, AN, Allen, VG, Grewal, R, MacPherson, PA, Rachlis, A, Walmsley, S et al.. Enhanced syphilis screening among HIV-positive men (ESSAHM): a study protocol for a clinic-randomized trial with stepped wedge design. Implement Sci. 2016;11 :8. doi: 10.1186/s13012-016-0371-0. PubMed PMID:26772390 PubMed Central PMC4715363.
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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