Increase in transmitted HIV drug resistance among persons undergoing genotypic resistance testing in Ontario, Canada, 2002-09

Burchell, Ann N, Bayoumi, Ahmed M, Rourke, Sean B, Major, Carol, Gardner, Sandra, Sandstrom, Paul, Rachlis, Anita, Taylor, Darien, Mazzulli, Tony, Fisher, Mark, Brooks, James, Fisher, Martin and The OHTN Cohort Study Research Team, (2012) Increase in transmitted HIV drug resistance among persons undergoing genotypic resistance testing in Ontario, Canada, 2002-09. The Journal of Antimicrobial Chemotherapy, 67 (11). pp. 2755-2765. ISSN 1460-2091

Full text not available from this repository.



To characterize persons undergoing HIV genotypic resistance testing (GRT) while treatment naive and to estimate the prevalence of transmitted HIV drug resistance (TDR) among HIV-positive outpatients in Ontario, Canada.


We analysed data from a multi-site cohort of persons receiving HIV care. Data were obtained from medical chart abstractions, interviews and record linkage with the Public Health Laboratories, Public Health Ontario. The analysis was restricted to 626 treatment-naive persons diagnosed in 2002-09. TDR mutations were identified using the calibrated population resistance tool. We used descriptive statistics and regression methods to characterize treatment-naive GRT test uptake and patterns of TDR.


Overall, 53.2% (333/626) of participants had baseline GRT. The proportion increased with year of HIV diagnosis from 30.0% in 2002 to 82.6% in 2009 (P < 0.0001). Among those tested, 13.6% (CI 9.9-17.3%) had one or more drug resistance mutations, and 8.8% (CI 5.7-11.8%), 4.8% (CI 2.5-7.2%) and 2.7% (CI 1.0-4.5%) had mutations conferring resistance to nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs), respectively. TDR prevalence increased from 2002-07 to 2008-09 (adjusted OR 3.7, 95% CI 1.7-8.2), driven by a higher proportion with NRTI (18.2% versus 5.9%, P = 0.0009) and NNRTI mutations (11.7% versus 2.8%, P = 0.004) in the later time period. PI TDR remained unchanged.


Baseline GRT increased dramatically since 2002, but remains below 100%. The prevalence of overall TDR tripled due to increases in NRTI and NNRTI mutations. These findings highlight the value of routine baseline GRT for TDR surveillance and patient care.

Item Type: Article
Schools and Departments: Brighton and Sussex Medical School > Brighton and Sussex Medical School
Subjects: R Medicine > RA Public aspects of medicine > RA0421 Public health. Hygiene. Preventive Medicine > RA0643 Communicable diseases and public health > RA0644 Individual diseases or groups of diseases, A-Z > RA0644.A25 AIDS. HIV infections
Related URLs:
Depositing User: Ellen Thomas
Date Deposited: 25 Nov 2013 16:13
Last Modified: 25 Nov 2013 16:13
📧 Request an update