BACKGROUND: Accurate quantification of the prevalence of human immunodeficiency virus type 1 (HIV-1) drug resistance in patients who are receiving antiretroviral therapy (ART) is difficult, and results from previous studies vary. We attempted to assess the prevalence and dynamics of resistance in a highly representative patient cohort from Switzerland. METHODS: On the basis of genotypic resistance test results and clinical data, we grouped patients according to their risk of harboring resistant viruses. Estimates of resistance prevalence were calculated on the basis of either the proportion of individuals with a virologic failure or confirmed drug resistance (lower estimate) or the frequency-weighted average of risk group-specific probabilities for the presence of drug resistance mutations (upper estimate). RESULTS: Lower and upper estimates of drug resistance prevalence in 8064 ART-exposed patients were 50% and 57% in 1999 and 37% and 45% in 2007, respectively. This decrease was driven by 2 mechanisms: loss to follow-up or death of high-risk patients exposed to mono- or dual-nucleoside reverse-transcriptase inhibitor therapy (lower estimates range from 72% to 75%) and continued enrollment of low-risk patients who were taking combination ART containing boosted protease inhibitors or nonnucleoside reverse-transcriptase inhibitors as first-line therapy (lower estimates range from 7% to 12%). A subset of 4184 participants (52%) had >or= 1 study visit per year during 2002-2007. In this subset, lower and upper estimates increased from 45% to 49% and from 52% to 55%, respectively. Yearly increases in prevalence were becoming smaller in later years. CONCLUSIONS: Contrary to earlier predictions, in situations of free access to drugs, close monitoring, and rapid introduction of new potent therapies, the emergence of drug-resistant viruses can be minimized at the population level. Moreover, this study demonstrates the necessity of interpreting time trends in the context of evolving cohort populations.
BACKGROUND: Accurate quantification of the prevalence of human immunodeficiency virus type 1 (HIV-1) drug resistance in patients who are receiving antiretroviral therapy (ART) is difficult, and results from previous studies vary. We attempted to assess the prevalence and dynamics of resistance in a highly representative patient cohort from Switzerland. METHODS: On the basis of genotypic resistance test results and clinical data, we grouped patients according to their risk of harboring resistant viruses. Estimates of resistance prevalence were calculated on the basis of either the proportion of individuals with a virologic failure or confirmed drug resistance (lower estimate) or the frequency-weighted average of risk group-specific probabilities for the presence of drug resistance mutations (upper estimate). RESULTS: Lower and upper estimates of drug resistance prevalence in 8064 ART-exposed patients were 50% and 57% in 1999 and 37% and 45% in 2007, respectively. This decrease was driven by 2 mechanisms: loss to follow-up or death of high-risk patients exposed to mono- or dual-nucleoside reverse-transcriptase inhibitor therapy (lower estimates range from 72% to 75%) and continued enrollment of low-risk patients who were taking combination ART containing boosted protease inhibitors or nonnucleoside reverse-transcriptase inhibitors as first-line therapy (lower estimates range from 7% to 12%). A subset of 4184 participants (52%) had >or= 1 study visit per year during 2002-2007. In this subset, lower and upper estimates increased from 45% to 49% and from 52% to 55%, respectively. Yearly increases in prevalence were becoming smaller in later years. CONCLUSIONS: Contrary to earlier predictions, in situations of free access to drugs, close monitoring, and rapid introduction of new potent therapies, the emergence of drug-resistant viruses can be minimized at the population level. Moreover, this study demonstrates the necessity of interpreting time trends in the context of evolving cohort populations.
Authors: Regina B Osih; Patrick Taffé; Martin Rickenbach; Angèle Gayet-Ageron; Luigia Elzi; Christoph Fux; Milos Opravil; Enos Bernasconi; Patrick Schmid; Huldrych F Günthard; Matthias Cavassini Journal: AIDS Res Hum Retroviruses Date: 2010-10-07 Impact factor: 2.205
Authors: Prema Menezes; David Rosen; David A Wohl; Nichole Kiziah; Joseph Sebastian; Joseph J Eron; Becky White Journal: AIDS Res Hum Retroviruses Date: 2012-11-19 Impact factor: 2.205
Authors: Edward M Gardner; Margaret P McLees; John F Steiner; Carlos Del Rio; William J Burman Journal: Clin Infect Dis Date: 2011-03-15 Impact factor: 9.079
Authors: Vikram S Gill; Viviane D Lima; Wen Zhang; Brian Wynhoven; Benita Yip; Robert S Hogg; Julio S G Montaner; P Richard Harrigan Journal: Clin Infect Dis Date: 2010-01-01 Impact factor: 9.079
Authors: Kartik K Venkatesh; Allison K DeLong; Rami Kantor; Stacey Chapman; Jessica Ingersoll; Jaclynn Kurpewski; Maria Pia De Pasquale; Richard D'Aquila; Angela M Caliendo; Susan Cu-Uvin Journal: J Womens Health (Larchmt) Date: 2013-03-26 Impact factor: 2.681
Authors: Steven G Deeks; Stephen J Gange; Mari M Kitahata; Michael S Saag; Amy C Justice; Robert S Hogg; Joseph J Eron; John T Brooks; Sean B Rourke; M John Gill; Ronald J Bosch; Constance A Benson; Ann C Collier; Jeffrey N Martin; Marina B Klein; Lisa P Jacobson; Benigno Rodriguez; Timothy R Sterling; Gregory D Kirk; Sonia Napravnik; Anita R Rachlis; Liviana M Calzavara; Michael A Horberg; Michael J Silverberg; Kelly A Gebo; Margot B Kushel; James J Goedert; Rosemary G McKaig; Richard D Moore Journal: Clin Infect Dis Date: 2009-11-15 Impact factor: 9.079
Authors: Jan Fehr; Tracy R Glass; Séverine Louvel; François Hamy; Hans H Hirsch; Viktor von Wyl; Jürg Böni; Sabine Yerly; Philippe Bürgisser; Matthias Cavassini; Christoph A Fux; Bernard Hirschel; Pietro Vernazza; Gladys Martinetti; Enos Bernasconi; Huldrych F Günthard; Manuel Battegay; Heiner C Bucher; Thomas Klimkait Journal: J Transl Med Date: 2011-01-21 Impact factor: 5.531