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About Sickkids
About SickKids

Sean (Ari) Bitnun, MD, MSc, FRCPC

The Hospital for Sick Children
Staff physician & Consultant in Infectious Diseases
Infectious Diseases

Research Institute
Project Investigator
Research Institute

University of Toronto
Assistant Professor

Email: ari.bitnun@sickkids.ca

Brief Biography

Dr. Bitnun is an Associate Professor of Paediatrics at the University of Toronto. His primary appointment is with the Division of Infectious Diseases, Department of Pediatrics at the Hospital for Sick Children.  

Dr. Bitnun received his MD from the University of British Columbia, Vancouver, Canada. He completed his pediatric residency training in Israel and subsequently, clinical and research infectious diseases fellowships at the Hospital for Sick Children, Toronto. He obtained a Master of Science Degree in Clinical Epidemiology through the University of Toronto. He has been a full time staff physician in the Division of Infectious Diseases, The Hospital for Sick Children, Toronto, since 2004.

Dr Bitnun is an Academic Clinician. He does inpatient and outpatient infectious diseases consultations. He is the director of the Family Centered HIV Clinic and the Congenital & Perinatal Infection Clinic.

Research Interests

A. Childhood encephalitis
Dr. Bitnun is the lead investigator for the Hospital for Sick Children Encephalitis Registry, a project designed to enhance our understanding of the etiology and pathogenesis of acute childhood encephalitis.

B. Pediatric HIV
Dr. Bitnun conducts clinical research pertaining to pediatric HIV and prevention of vertical HIV transmission.

C. Congenital and Perinatal Infections
Dr Bitnun has an interest in congenital infections, particularly congenital CMV.

External Funding

  • Canadian Institutes for Health Research (CIHR)
  • Canadian Foundation for AIDS Research (CANFAR)
  • Physician’s Services Incorporated Foundation


  • Pediatric Resident Lecture Series (PERLs) teaching award (2007)
  • Kindred Spirit Tapestry Award - awarded to the SickKids HIV care team (2011)  
  • Junior Faculty Award for Clinical Excellence in Paediatric Medical Care (2011)


  1. Bitnun A, Yeh EA. Acute flaccid paralysis and enteroviral infections. Current Infectious Disease Reports 2018 (in press).
  2. Bitnun A, Lee T, Brophy J, Samson LE, Kakkar F, Vaudry W, Tan B, Money DM, Singer J, Sauve L, Alimenti A for the Canadian Perinatal HIV Surveillance Program Missed Opportunities for the Prevention of Vertical HIV Transmission in Canada, 1997 – 2015. cmajOPEN 2018;6(2):E202-E210.
  3. Lau E, Brophy J, Samson L, Kakkar F, Campbell D, Yudin M, Murphy K, Seto W, Colantonio, Read S, Bitnun A: Nevirapine pharmacokinetics and safety in neonates receiving combination antiretroviral therapy for prevention of vertical transmission. J AIDS 2017;74(5):493-498.
  4. Kakkar F, Samson L, Brophy J, Vaudry W, Lemeur JB, Lapointe N, Read SE, Bitnun A. Safety of combination antiretroviral prophylaxis in high-risk HIV-exposed newborns in Canada. Journal of the International AIDS Society (JIAS) 2016, 19:20520.
  5. Bitnun A, Richardson SE. Childhood encephalitis in Canada in 2015. Canadian Journal of Infectious Diseases & Medical Microbiology 2015;26(2):69-72.
  6. Al-Zaidy SA, MacGregor D, Mahant S, Richardson S, Bitnun A. Neurological complications of PCR-proven M. pneumoniae infections in children: prodromal illness duration may reflect pathogenetic mechanism. Clinical Infectious Diseases 2015;61(7):1082-8.
  7. Bitnun A, Samson L, Chun TW, Kakkar F, Brophy J, Murray D, Justement J, Soudeyns H, Ostrowski M, Mujib S, Harrigan R, Kim J, Sandstrom P, Read S: Early initiation of combination antiretroviral therapy in HIV-1-infected newborn infants can achieve sustained virologic suppression with no measurable proviral DNA or replication competent virus in peripheral blood.  Clinical Infectious Diseases 2014;59(7):1012-1019.
  8. Bridge M, MacGregor D, Richardson S, Mahant S, Tran D, Bitnun A: Central nervous system (CNS) complications of varicella zoster virus infection: a retrospective 10 year review. Journal of Pediatrics 2014;165:779-785.
  9. Schwartz K, Richardson S, Ward K, Donaldson C, Macgregor D, Banwell B, Mahant S, Bitnun A: Delayed primary HHV-7 infection and neurologic disease.  Pediatrics 2014;6:e1541-1547.
  10. Bitnun A, Brophy J, Samson L, Alimienti A, Kakkar F, Lammare V, Moore D, Karatzios C, Seigel S, Sauve L, Vaudry, W, Yudin M, Money D for the Canadian Paediatric and Perinatal AIDS research Group & the Infectious Diseases Committee of the Society of Obstetrics and Gynecology of Canada. Prevention of vertical HIV transmission and management of the HIV-exposed infant in Canada in 2014. Canadian Journal of Infectious Diseases & Medical Microbiology 2014;25(2):75-77.
  11.  Venkatesan A, Tunkel AR, Bloch KC, Lauring AS, Sejvar J, Bitnun A, Stahl J-P, Mailles A, Drebot M, Rupprecht CE, Yoder J, Cope JR, Wilson MR, Whitley RJ, Sullivan J, Granerod J, Jones C, Eastwood K, Ward KN, Durrheim DN, Solbrig MV, Guo-Dong L, Glaser CA on behalf of the International Encephalitis Consortium: Case definitions, diagnostic algorithms, and priorities in encephalitis: consensus statement of the International Encephalitis Consortium. Clinical Infectious Diseases 2013;57(8):1114-1128.
  12. Kakalia S, Sochett E, Stephens D, Assor E, Read S, Bitnun A: Vitamin D supplementation and CD4 count in HIV-infected children.  Journal of Pediatrics 2011;159:951-957.  
  13. Bitnun A, Richardson SE: Mycoplasma pneumoniae: innocent bystander or a true cause of central nervous system disease.  Current Infectious Disease Reports 2010; 12:282-290.  
  14. Amin R, Richardson SE, MacGregor D, Tellier R, Heurter H, Fearon M, Ford-Jones E, Bitnun A: Acute childhood encephalitis and encephalopathy associated with influenza: a prospective 11-year review.  Pediatric Infectious Disease Journal 2008;7:390-395.  
  15. Bitnun A, Sochett E, Dick P, To T, Jefferies C, Babyn P, Forbes J, Read S, King SM: Insulin sensitivity and beta-cell function in protease inhibitor-treated and -naive HIV-infected children.  Journal of Clinical Endocrinology and Metabolism 2005;90:168-174.  
  16. Bitnun A, Allen U, Heurter H, King S, Opavsky MA, Ford-Jones EL, Matlow A, Kitai I, Tellier R, Richardson S, Manson D, Babyn P, Read S and other members of the Hospital for Sick Children SARS Investigation Team: Children hospitalized with severe acute respiratory syndrome-related illness in Toronto.  Pediatrics 2003;112:e261.
  17. Bitnun A, Sochett E, Babyn P, Holowka S, Stephens D, Arneson C, Read S, King SM: Serum lipids, glucose homeostasis and abdominal adipose tissue distribution in protease inhibitor-treated and -naive HIV-infected children.  AIDS 2003;17:1319-1327.
  18. Bitnun A, King SM, Arneson C, Read SE: Failure to Prevent Perinatal HIV Infection.  Canadian Medical Association Journal 2002;166:904-905.
  19. Bitnun A, Ford-Jones EL, Petric M, MacGregor D, Heurter H, Nelson S, Grant Johnson, Richardson S: Acute childhood encephalitis and Mycoplasma pneumoniae.  Clinical Infectious Disease 2001;32:1674-1684.