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Sun M, Fu X. Competitive dual-strain SIS epidemiological models with awareness programs in heterogeneous networks: two modeling approaches. J Math Biol 2023; 87:14. [PMID: 37336794 DOI: 10.1007/s00285-023-01945-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 04/06/2023] [Accepted: 06/02/2023] [Indexed: 06/21/2023]
Abstract
Epidemic diseases and media campaigns are closely associated with each other. Considering most epidemics have multiple pathogenic strains, in this paper, we take the lead in proposing two multi-strain SIS epidemic models in heterogeneous networks incorporating awareness programs due to media. For the first model, we assume that the transmission rates for strain 1 and strain 2 depend on the level of awareness campaigns. For the second one, we further suppose that awareness divides susceptible population into two different subclasses. After defining the basic reproductive numbers for the whole model and each strain, we obtain the analytical conditions that determine the extinction, coexistence and absolute dominance of two strains. Moreover, we also formulate its optimal control problem and identify an optimal implementation pair of awareness campaigns using optimal control theory. Given the complexity of the second model, we use the numerical simulations to visualize its different types of dynamical behaviors. Through theoretical and numerical analysis of these two models, we discover some new phenomena. For example, during the persistence analysis of the first model, we find that the characteristic polynomials of two boundary equilibria may have a pair of pure imaginary roots, implying that Hopf bifurcation and periodic solutions may appear. Most strikingly, multistability occurs in the second model and the growth rate of awareness programs (triggered by the infection prevalence) has a multistage impact on the final size of two strains. The numerical results suggest that the spread of a two-strain epidemic can be controlled (even be eradicated) by taking the measures of enhancing awareness transmission, reducing memory fading of aware individuals and ensuring high-level influx and rapid growth of awareness programs appropriately.
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Affiliation(s)
- Mengfeng Sun
- Department of Mathematics, Shanghai University, Shanghai, 200444, China.
| | - Xinchu Fu
- Department of Mathematics, Shanghai University, Shanghai, 200444, China
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Lai H, Li R, Li Z, Zhang B, Li C, Song C, Zhao Q, Huang J, Zhu Q, Liang S, Chen H, Li J, Liao L, Shao Y, Xing H, Ruan Y, Lan G, Zhang L, Shen M. Modelling the impact of treatment adherence on the transmission of HIV drug resistance. J Antimicrob Chemother 2023:dkad186. [PMID: 37311203 DOI: 10.1093/jac/dkad186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023] Open
Abstract
INTRODUCTION A lower adherence rate (percentage of individuals taking drugs as prescribed) to ART may increase the risk of emergence and transmission of HIV drug resistance, decrease treatment efficacy, and increase mortality rate. Exploring the impact of ART adherence on the transmission of drug resistance could provide insights in controlling the HIV epidemic. METHODS We proposed a dynamic transmission model incorporating the CD4 cell count-dependent rates of diagnosis, treatment and adherence with transmitted drug resistance (TDR) and acquired drug resistance. This model was calibrated and validated by 2008-2018 HIV/AIDS surveillance data and prevalence of TDR among newly diagnosed treatment-naive individuals from Guangxi, China, respectively. We aimed to identify the impact of adherence on drug resistance and deaths during expanding ART. RESULTS In the base case (ART at 90% adherence and 79% coverage), we projected the cumulative total new infections, new drug-resistant infections, and HIV-related deaths between 2022 and 2050 would be 420 539, 34 751 and 321 671. Increasing coverage to 95% would reduce the above total new infections (deaths) by 18.85% (15.75%). Reducing adherence to below 57.08% (40.84%) would offset these benefits of increasing coverage to 95% in reducing infections (deaths). Every 10% decrease in adherence would need 5.07% (3.62%) increase in coverage to avoid an increase in infections (deaths). Increasing coverage to 95% with 90% (80%) adherence would increase the above drug-resistant infections by 11.66% (32.98%). CONCLUSIONS A decrease in adherence might offset the benefits of ART expansion and exacerbate the transmission of drug resistance. Ensuring treated patients' adherence might be as important as expanding ART to untreated individuals.
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Affiliation(s)
- Hao Lai
- China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Rui Li
- China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Zengbin Li
- China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Baoming Zhang
- College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Chao Li
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - Chang Song
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing 102206, P.R. China
| | - Quanbi Zhao
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing 102206, P.R. China
| | - Jinghua Huang
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Qiuying Zhu
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Shujia Liang
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Huanhuan Chen
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Jianjun Li
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Lingjie Liao
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing 102206, P.R. China
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Yiming Shao
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing 102206, P.R. China
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Hui Xing
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing 102206, P.R. China
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Yuhua Ruan
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing 102206, P.R. China
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Guanghua Lan
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning 530028, P.R. China
| | - Lei Zhang
- China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
- Artificial Intelligence and Modelling in Epidemiology Program, Melbourne Sexual Health Centre, Alfred Health, Melbourne, Australia
- Central Clinical School, Faculty of Medicine, Monash University, Melbourne, Australia
| | - Mingwang Shen
- China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
- Key Laboratory for Disease Prevention and Control and Health Promotion of Shaanxi Province, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
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Shen M, Xiao Y, Rong L, Zhuang G, Song C, Zhao Q, Huang J, Zhu Q, Liang S, Chen H, Li J, Liao L, Shao Y, Xing H, Ruan Y, Lan G. The impact of attrition on the transmission of HIV and drug resistance. AIDS 2023; 37:1137-1145. [PMID: 36927994 DOI: 10.1097/qad.0000000000003528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
BACKGROUND Attrition due to loss to follow-up or termination of antiretroviral therapy (ART) among HIV-infected patients in care may increase the risk of emergence and transmission of drug resistance (TDR), diminish benefit of treatment, and increase morbidity and mortality. Understanding the impact of attrition on the epidemic is essential to provide interventions for improving retention in care. METHODS We developed a comprehensive HIV transmission dynamics model by considering CD4 + cell count dependent diagnosis, treatment, and attrition involving TDR and acquired drug resistance. The model was calibrated by 11 groups HIV/AIDS surveillance data during 2008-2018 from Guangxi, China, and validated by the prevalence of TDR among diagnosed treatment-naive individuals. We aimed to investigate how attrition would affect the transmission of HIV and drug-resistance when expanding ART. RESULTS In the base case with CD4 + cell count dependent per capita attrition rates 0.025∼0.15 and treatment rates 0.23∼0.42, we projected cumulative total new infections, new drug-resistant infections, and HIV-related deaths over 2022-2030 would be 145 391, 7637, and 51 965, respectively. Increasing treatment rates by 0.1∼0.2 can decrease the above total new infections (deaths) by 1.63∼2.93% (3.52∼6.16%). However, even 0.0114∼0.0220 (0.0352∼0.0695) increase in attrition rates would offset this benefit of decreasing infections (deaths). Increasing treatment rates (attrition rates) by 0.05∼0.1 would increase the above drug-resistant infections by 0.16∼0.30% (22.18∼41.15%). CONCLUSION A minor increase in attrition can offset the benefit of treatment expansion and increase the transmission of HIV drug resistance. Reducing attrition rates for patients already in treatment may be as important as expanding treatment for untreated patients.
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Affiliation(s)
- Mingwang Shen
- China-Australia Joint Research Centre for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Center
- Key Laboratory for Disease Prevention and Control and Health Promotion of Shaanxi
| | - Yanni Xiao
- School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Libin Rong
- Department of Mathematics, University of Florida, Gainesville, Florida, USA
| | - Guihua Zhuang
- China-Australia Joint Research Centre for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Center
- Key Laboratory for Disease Prevention and Control and Health Promotion of Shaanxi
| | - Chang Song
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing
| | - Quanbi Zhao
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing
| | - Jinghua Huang
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Qiuying Zhu
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Shujia Liang
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Huanhuan Chen
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Jianjun Li
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Lingjie Liao
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Yiming Shao
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Hui Xing
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Yuhua Ruan
- State Key Laboratory of Infectious Disease Prevention and Control (SKLID), National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
| | - Guanghua Lan
- Guangxi Key Laboratory of Major Infectious Disease Prevention Control and Biosafety Emergency Response, Guangxi Center for Disease Control and Prevention, Nanning, China
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Wang Z, Zhang Z, Zhang C, Jin X, Wu J, Su B, Shen Y, Ruan Y, Xing H, Lou J. Trace the History of HIV and Predict Its Future through Genetic Sequences. Trop Med Infect Dis 2022; 7:tropicalmed7080190. [PMID: 36006282 PMCID: PMC9416588 DOI: 10.3390/tropicalmed7080190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 11/16/2022] Open
Abstract
Traditional methods of quantifying epidemic spread are based on surveillance data. The most widely used surveillance data are normally incidence data from case reports and hospital records, which are normally susceptible to human error, and sometimes, they even can be seriously error-prone and incomplete when collected during a destructive epidemic. In this manuscript, we introduce a new method to study the spread of infectious disease. We gave an example of how to use this method to predict the virus spreading using the HIV gene sequences data of China. First, we applied Bayesian inference to gene sequences of two main subtypes of the HIV virus to infer the effective reproduction number (GRe(t)) to trace the history of HIV transmission. Second, a dynamic model was established to forecast the spread of HIV medication resistance in the future and also obtain its effective reproduction number (MRe(t)). Through fitting the two effective reproduction numbers obtained from the two separate ways above, some crucial parameters for the dynamic model were obtained. Simply raising the treatment rate has no impact on lowering the infection rate, according to the dynamics model research, but would instead increase the rate of medication resistance. The negative relationship between the prevalence of HIV and the survivorship of infected individuals following treatment may be to blame for this. Reducing the MSM population’s number of sexual partners is a more efficient strategy to reduce transmission per the sensitivity analysis.
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Affiliation(s)
- Zhen Wang
- Department of Mathematics, Shanghai University, Shanghai 200444, China
| | - Zhiyuan Zhang
- Department of Statistics, Columbia University, New York, NY 10027, USA
| | - Chen Zhang
- School of Nursing, University of Rochester, Rochester, NY 14627, USA
| | - Xin Jin
- Department of Mathematics, Shanghai University, Shanghai 200444, China
| | - Jianjun Wu
- Anhui Provincial Center for Disease Control and Prevention, Hefei 230601, China
| | - Bin Su
- Anhui Provincial Center for Disease Control and Prevention, Hefei 230601, China
| | - Yuelan Shen
- Anhui Provincial Center for Disease Control and Prevention, Hefei 230601, China
| | - Yuhua Ruan
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, and National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Hui Xing
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, and National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Jie Lou
- Department of Mathematics, Shanghai University, Shanghai 200444, China
- Correspondence:
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Iyanda AE, Chima-adaralegbe N, Adeleke R, Lu Y. Covariation of suicide and HIV in 186 countries: a spatial autoregressive and multiscale geographically weighted regression analyses. J Public Health (Oxf) 2022; 30:1545-1555. [DOI: 10.1007/s10389-020-01436-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
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Jin X, Wang Z, Zhang Z, Wu H, Ruan Y, Zhang C, Kang R, Xing H, Lou J. The transmission of drug-resistant strains of HIV in heterosexual populations based on genetic sequences. PLoS One 2021; 16:e0259023. [PMID: 34851959 PMCID: PMC8635345 DOI: 10.1371/journal.pone.0259023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 10/11/2021] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND China's National Free Antiretroviral Treatment Program (NFATP) has substantially reduced morbidity and HIV/AIDS incidence since 2003. However, HIV resistance to antiretroviral drugs (ARVs) has been a major challenge for the current treatment of HIV/AIDS in China. METHODS In the current study, we established a nested dynamic model to predict the multi-drug resistance dynamics of HIV among the heterosexual population and evaluated the impact of intervention measures on the transmission of drug resistance. We obtained an effective reproductive number [Formula: see text] from each sub-model held at different stages of the dynamic model. Meanwhile, we applied Bayesian phylogenetic methods to infer the weighted average effective reproductive number [Formula: see text] from four HIV subtypes that sampled from 912 HIV-positive patients in China. It is an original and innovative method by fitting [Formula: see text] to [Formula: see text] by Markov Chain Monte Carlo (MCMC) to generate unknown parameters in [Formula: see text]. RESULTS By analyzing the HIV gene sequences, we inferred that the most recent common ancestor of CRF01AE, CRF07BC, CRF08BC, and CRFBC dated from 1994, 1990, 1993 and 1990, respectively. The weighted average effective reproductive number [Formula: see text] dropped from 1.95 in 1994 to 1.73 in 2018. Considering different interventions, we used a macro dynamic model to predict the trend of HIV resistance. The results show that the number of new infections and total drug resistance under the baseline parameter (S1) are 253,422 and 213,250 in 2025, respectively. Comparing with the numbers under the target treatment rate (S2), they were 219,717 and 236,890, respectively. However, under the ideal treatment target (S3, the treatment rate reaches 90% and the treatment success rate reaches 90%), the number of new infections shows a declining trend and will decrease to 46,559 by 2025. Compared with S1 and S2, the total number of resistance also decreased to 160,899 in 2025. CONCLUSION With the promotion of NFATP in China, HIV resistance to ARVs is inevitable. The strategy of increasing the treatment rate would not only ineffectively curb the epidemic, but also deteriorate drug resistance issue. Whereas, a combination of intervention strategies (the treatment rate reaches 90% and the treatment success rate reaches 90%) can greatly reduce both infection and drug resistance rate than applying one strategy alone.
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Affiliation(s)
- Xin Jin
- Department of Mathematics, Shanghai University, Shanghai, China
| | - Zhen Wang
- Department of Mathematics, Shanghai University, Shanghai, China
| | - Zhiyuan Zhang
- Department of Statistics, Columbia University, New York, NY, United States of America
| | - Hui Wu
- Department of Mathematics, Shanghai University, Shanghai, China
| | - Yuhua Ruan
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases and National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Chen Zhang
- School of Nursing, University of Rochester, Rochester, NY, United States of America
| | - Ruihua Kang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases and National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Department of Disease Prevention and Control, The Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, China
| | - Hui Xing
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases and National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jie Lou
- Department of Mathematics, Shanghai University, Shanghai, China
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Papa F, Felici G, Franzetti M, Gandolfi A, Sinisgalli C. Impact of ART-induced viral suppression on the HIV epidemic in Italy. Math Med Biol 2021; 37:183-211. [PMID: 31162541 DOI: 10.1093/imammb/dqz010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 04/04/2019] [Accepted: 04/15/2019] [Indexed: 01/17/2023]
Abstract
The present study aims to clarify the role of the fraction of patients under antiretroviral therapy (ART) achieving viral suppression (VS) (i.e. having plasma viral load below the detectability threshold) on the human immunodeficiency virus (HIV) epidemic in Italy. Based on the hypothesis that VS makes the virus untransmittable, we extend a previous model and we develop a time-varying ordinary differential equation model with immigration and treatment, where the naive and non-naive populations of infected are distinguished, and different compartments account for treated subjects virally suppressed and not suppressed. Moreover, naive and non-naive individuals with acquired immune deficiency syndrome (AIDS) are considered separately. Clinical data stored in the nationwide database Antiviral Response Cohort Analysis are used to reconstruct the history of the fraction of virally suppressed patients since highly active ART introduction, as well as to assess some model parameters. Other parameters are set according to the literature and the final model calibration is obtained by fitting epidemic data over the years 2003-2015. Predictions on the evolution of the HIV epidemic up to the end of 2035 are made assuming different future trends of the fraction of virally suppressed patients and different eligibility criteria for treatment. Increasing the VS fraction is found to reduce the incidence, the new cases of AIDS and the deaths from AIDS per year, especially in combination with early ART initiation. The asymptotic properties of a time-invariant formulation of the model are studied, and the existence and global asymptotic stability of a unique positive equilibrium are proved.
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Affiliation(s)
- Federico Papa
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Via dei Taurini, Roma, Italy
| | - Giovanni Felici
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Via dei Taurini, Roma, Italy
| | - Marco Franzetti
- Infectious Diseases Unit, 'A. Manzoni' Hospital, Via dell'Eremo, 9/11, Lecco, Italy
| | - Alberto Gandolfi
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Via dei Taurini, Roma, Italy
| | - Carmela Sinisgalli
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Via dei Taurini, Roma, Italy
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Lu Z, Wang L, Wang LP, Xing H, Fu G, Yan H, Wang L, Li Z, Xu J, Wang N, Wang K, Peng Z. A mathematical model for HIV prevention and control among men who have sex with men in China. Epidemiol Infect 2020; 148:e224. [PMID: 32336300 DOI: 10.1017/S0950268820000850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In recent years, men who have sex with men (MSM) constitute a major group of HIV transmission in China. High primary drug-resistance (PDR) rate in MSM also represents a serious challenge for the Chinese antiretroviral therapy (ART) program. To assess the efficiency of ART in controlling HIV/AIDS infection among MSM, we developed a compartmental model for the annually reported HIV/AIDS MSM from 2007 to 2019 in the Zhejiang Province of China. R0 was 2.3946 (95% CI (2.2961–2.4881)). We predict that 90% of diagnosed HIV/AIDS individuals will have received treatment till 2020, while the proportion of the diagnosed remains as low as 40%. Even when the proportion of the diagnosed reaches 90%, R0 is still larger than the level of AIDS epidemic elimination. ART can effectively control the spread of HIV, even in the presence of drug resistance. The 90-90-90 strategy alone may not eliminate the HIV epidemic in Chinese MSM. Behavioural and biologic interventions are the most effective interventions to control the HIV/AIDS epidemic among MSM.
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Jiang T, Chen XS. Outcome Impacts Due to Pathogen-Specific Antimicrobial Resistance: A Narrative Review of Published Literature. Int J Environ Res Public Health 2020; 17:ijerph17041395. [PMID: 32098182 PMCID: PMC7068360 DOI: 10.3390/ijerph17041395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 01/31/2020] [Accepted: 02/19/2020] [Indexed: 12/19/2022]
Abstract
Antimicrobial resistance (AMR) has become a global threat to not only public health impacts but also clinical and economic outcomes. During the past decades, there have been many studies focusing on surveillance, mechanisms, and diagnostics of AMR in infectious diseases but the impacts on public health, clinical and economic outcomes due to emergence of these AMRs are rarely studied and reported. This review was aimed to summarize the findings from published studies to report the outcome impacts due to AMR of malaria, tuberculosis and HIV and briefly discuss the implications for application to other infectious diseases. PubMed/Medline and Google Scholar databases were used for search of empirical and peer-reviewed papers reporting public health, clinical and economic outcomes due to AMR of malaria, tuberculosis and HIV. Papers published through 1 December 2019 were included in this review. A total of 76 studies were included for this review, including 16, 49 and 11 on public health, clinical and economic outcomes, respectively. The synthesized data indicated that the emergence and spread of AMR of malaria, tuberculosis and HIV have resulted in adverse public health, clinical and economic outcomes. AMR of malaria, tuberculosis and HIV results in significant adverse impacts on public health, clinical and economic outcomes. Evidence from this review suggests the needs to consider the similar studies for other infectious diseases.
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Affiliation(s)
- Tingting Jiang
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China;
- National Center for STD Control, Chinese Center for Disease Control and Prevention, Nanjing 210042, China
| | - Xiang-Sheng Chen
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China;
- National Center for STD Control, Chinese Center for Disease Control and Prevention, Nanjing 210042, China
- Correspondence: ; Tel.: +86-25-8547-8901
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Northrop AJ, Pomeroy LW. Forecasting Prevalence of HIV-1 Integrase Strand Transfer Inhibitor (INSTI) Drug Resistance: A Modeling Study. J Acquir Immune Defic Syndr 2020; 83:65-71. [PMID: 31809362 DOI: 10.1097/QAI.0000000000002212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Antiretroviral therapy (ART) is a cornerstone of HIV-1 treatment and provides significant health benefits for patients with responsive HIV-1 strains. Integrase strand transfer inhibitors (INSTIs) are the newest class of ART. Although most HIV-1 cases are responsive, a small number are already resistant. Here, we forecast the prevalence of INSTI resistance amid wide-spread use. METHODS We developed a stochastic model to simulate HIV-1 dynamics and INSTI resistance for raltegravir, elvitegravir, and dolutegravir. We forecast prevalence of INSTI resistance in adults living with HIV-1 over a 30-year period using parameter values and initial conditions that mimic HIV-1 dynamics Washington DC. We used the model to predict the amount of transmitted drug resistance (TDR) versus regimen-acquired drug resistance. RESULTS We forecast the prevalence of HIV-1 cases resistant to raltegravir as 0.41 (minimum: 0.21; maximum: 0.57), resistant to elvitegravir as 0.44 (minimum: 0.26; maximum: 0.60), and resistant to dolutegravir as 0.44 (minimum: 0.25; maximum: 0.65). Model output was greatly affected by the proportion of those living with HIV-1 on ART and the rate of converting from an INSTI-sensitive strain to an INSTI-resistant strain for chronically infected ART-experienced cases. We forecast that TDR will contribute minimally-if at all-to the overall proportion of resistant HIV-1 cases. CONCLUSIONS INSTI drug resistance has the potential to be a public health concern in the next 30 years. Although several parameters influence the predicted prevalence of INSTI drug resistance, TDR is unlikely to contribute substantially to future trends.
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11
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Shen M, Xiao Y, Rong L, Meyers LA. Conflict and accord of optimal treatment strategies for HIV infection within and between hosts. Math Biosci 2019; 309:107-117. [PMID: 30684516 PMCID: PMC10826718 DOI: 10.1016/j.mbs.2019.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 11/21/2022]
Abstract
Most of previous studies investigated the optimal control of HIV infection at either within-host or between-host level. However, the optimal treatment strategy for the individual may not be optimal for the population and vice versa. To determine when the two-level optimal controls are in accord or conflict, we develop a multi-scale model using various functions that link the viral load within host and the transmission rate between hosts, calibrated by cohort data. We obtain the within-host optimal treatment scheme that minimizes the viral load and maximizes the count of healthy cells at the individual level, and the coupled optimal scheme that minimizes the basic reproduction number at the population level. Mathematical analysis shows that whether the two-level optimal controls coincide depends on the sign of the product of their switching functions. Numerical results suggest that they are in accord for a high maximal drug efficacy but may conflict for a low drug efficacy. Using the multi-scale model, we also identify a threshold of the treatment effectiveness that determines how early treatment initiation can affect the disease dynamics among population. These results may help develop a synergistic treatment protocol beneficial to both HIV-infected individuals and the whole population.
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Affiliation(s)
- Mingwang Shen
- Department of Applied Mathematics, School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, PR China; Department of Epidemiology and Biostatistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, PR China
| | - Yanni Xiao
- Department of Applied Mathematics, School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, PR China.
| | - Libin Rong
- Department of Mathematics, University of Florida, Gainesville, FL 32611, USA
| | - Lauren Ancel Meyers
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas 78712, USA; The Santa Fe Institute, Santa Fe, New Mexico 87501, USA
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12
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Dalai SC, Junqueira DM, Wilkinson E, Mehra R, Kosakovsky Pond SL, Levy V, Israelski D, de Oliveira T, Katzenstein D. Combining Phylogenetic and Network Approaches to Identify HIV-1 Transmission Links in San Mateo County, California. Front Microbiol 2018; 9:2799. [PMID: 30574123 PMCID: PMC6292275 DOI: 10.3389/fmicb.2018.02799] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022] Open
Abstract
The HIV epidemic in San Mateo County is sustained by multiple overlapping risk groups and is an important hub for HIV transmission in northern California. Limited access to care has led historically to delayed clinical presentation, higher rates of opportunistic infections, and an increased prevalence of antiretroviral drug resistance. The virologic and clinical consequences of treatment within these multiple ethnic and behavioral groups are poorly understood, highlighting the need for efficient surveillance strategies that are able to elucidate transmission networks and drug resistance patterns. We obtained sequence data from a group of 316 HIV-positive individuals in the San Mateo AIDS Program over a 14-year period and integrated epidemiologic, phylogenetic, and network approaches to characterize transmission clusters, risk factors and drug resistance. Drug resistance mutations were identified using the Stanford HIV Drug Resistance Database. A maximum likelihood tree was inferred in RAxML and subjected to clustering analysis in Cluster Picker. Network analysis using pairwise genetic distances was performed in HIV-TRACE. Participants were primarily male (60%), white Hispanics and non-Hispanics (32%) and African American (20.6%). The most frequent behavior risk factor was male-male sex (33.5%), followed by heterosexual (23.4%) and injection drug use (9.5%). Nearly all sequences were subtype B (96%) with subtypes A, C, and CRF01_AE also observed. Sequences from 65% of participants had at least one drug resistance mutation. Clustered transmissions included a higher number of women when compared to non-clustered individuals and were more likely to include heterosexual or people who inject drugs (PWID). Detailed analysis of the largest network (N = 47) suggested that PWID played a central role in overall transmission of HIV-1 as well as bridging men who have sex with men (MSM) transmission with heterosexual/PWID among primarily African American men. Combined phylogenetic and network analysis of HIV sequence data identified several overlapping risk factors in the epidemic, including MSM, heterosexual and PWID transmission with a disproportionate impact on African Americans and a high prevalence of drug resistance.
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Affiliation(s)
- Sudeb C Dalai
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, United States.,Division of Epidemiology, School of Public Health, University of California, Berkeley, Berkeley, CA, United States
| | - Dennis Maletich Junqueira
- KwaZulu-Natal Research Innovation and Sequencing Platform, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.,School of Laboratory Medicine and Medical Science, Department of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Eduan Wilkinson
- KwaZulu-Natal Research Innovation and Sequencing Platform, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.,School of Laboratory Medicine and Medical Science, Department of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Renee Mehra
- Division of Hematology, Stanford University School of Medicine, Stanford, CA, United States
| | - Sergei L Kosakovsky Pond
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA, United States
| | - Vivian Levy
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, United States.,San Mateo Medical Center, San Mateo, CA, United States
| | - Dennis Israelski
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, United States.,San Mateo Medical Center, San Mateo, CA, United States
| | - Tulio de Oliveira
- KwaZulu-Natal Research Innovation and Sequencing Platform, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.,School of Laboratory Medicine and Medical Science, Department of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - David Katzenstein
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, United States
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13
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Palk L, Gerstoft J, Obel N, Blower S. A modeling study of the Danish HIV epidemic in men who have sex with men: travel, pre-exposure prophylaxis and elimination. Sci Rep 2018; 8:16003. [PMID: 30375426 PMCID: PMC6207710 DOI: 10.1038/s41598-018-33570-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 09/18/2018] [Indexed: 11/29/2022] Open
Abstract
UNAIDS has identified the Danish HIV epidemic in men who have sex with men (MSM) as a priority for elimination. Incidence is close to the elimination threshold of one new infection per year per 1,000 individuals. However, surveillance data show that HIV strains are being imported into Denmark, mainly due to travel. We use a transmission model to predict (from 2018 to 2030) the impact of pre-exposure prophylaxis (PrEP) on incidence. Our model reflects the current epidemic and diagnosis rates in the Danish MSM community. We conduct a sensitivity analysis based on 20,000 simulations, and assume that PrEP coverage could range from zero to 50% and diagnosis rates increase up to three-fold. We predict that incidence will fall below the elimination threshold, even without the introduction of PrEP, reaching 0.87 (median, 95% Confidence Interval: 0.65-1.23) new infections per 1,000 MSM by 2030. PrEP could reduce incidence to well below the threshold, if it results in a significant increase in diagnosis rates and reduces the number of infections occurring abroad. The Danish Medicine Agency and Danish Health Authority have recommended introducing PrEP. Our study provides strong support for this recommendation, and shows the importance of Danish MSM using PrEP when abroad.
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Affiliation(s)
- Laurence Palk
- Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, 90024, USA
| | - Jan Gerstoft
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Niels Obel
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Sally Blower
- Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, 90024, USA.
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14
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Ghosh I, Tiwari PK, Samanta S, Elmojtaba IM, Al-Salti N, Chattopadhyay J. A simple SI-type model for HIV/AIDS with media and self-imposed psychological fear. Math Biosci 2018; 306:160-9. [PMID: 30291857 DOI: 10.1016/j.mbs.2018.09.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/25/2018] [Accepted: 09/29/2018] [Indexed: 11/21/2022]
Abstract
Infectious diseases can have a large impact on society, as they cause morbidity, mortality, unemployment, inequality and other adverse effects. Mathematical models are invaluable tools in understanding and describing disease dynamics with preventive measures for controlling the disease. The roles of media coverage and behavioral changes due to externally imposed factors on the disease dynamics are well studied. However, the effect of self-imposed psychological fear on the disease transmission has not been considered in extant research, and this gap is addressed in the present investigation. We propose a simple SI-type model for HIV/AIDS to assess the effects of media and self-imposed psychological fear on the disease dynamics. Local and global dynamics of the system are studied. Global sensitivity analysis is performed to identify the most influential parameters that have significant impact on the basic reproduction number. After calibrating our model using HIV case data-sets for Uganda and Tanzania, we calculate the basic reproduction numbers in the study period using the estimated parameters. Furthermore, a comparison of the effects of awareness and self-imposed psychological fear effects reveals that awareness is more effective in eliminating the burden of HIV infection.
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15
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16
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Papa F, Binda F, Felici G, Franzetti M, Gandolfi A, Sinisgalli C, Balotta C. A simple model of HIV epidemic in Italy: The role of the antiretroviral treatment. Math Biosci Eng 2018; 15:181-207. [PMID: 29161832 DOI: 10.3934/mbe.2018008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In the present paper we propose a simple time-varying ODE model to describe the evolution of HIV epidemic in Italy. The model considers a single population of susceptibles, without distinction of high-risk groups within the general population, and accounts for the presence of immigration and emigration, modelling their effects on both the general demography and the dynamics of the infected subpopulations. To represent the intra-host disease progression, the untreated infected population is distributed over four compartments in cascade according to the CD4 counts. A further compartment is added to represent infected people under antiretroviral therapy. The per capita exit rate from treatment, due to voluntary interruption or failure of therapy, is assumed variable with time. The values of the model parameters not reported in the literature are assessed by fitting available epidemiological data over the decade 2003÷2012. Predictions until year 2025 are computed, enlightening the impact on the public health of the early initiation of the antiretroviral therapy. The benefits of this change in the treatment eligibility consist in reducing the HIV incidence rate, the rate of new AIDS cases, and the rate of death from AIDS. Analytical results about properties of the model in its time-invariant form are provided, in particular the global stability of the equilibrium points is established either in the absence and in the presence of infected among immigrants.
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Affiliation(s)
- Federico Papa
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Roma, Italy
| | - Francesca Binda
- Dipartimento di Scienze Biomediche e Cliniche 'L. Sacco', Sezione di Malattie Infettive e Immunopatologia, Università degli Studi di Milano, Milano, Italy
| | - Giovanni Felici
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Roma, Italy
| | - Marco Franzetti
- Dipartimento di Scienze Biomediche e Cliniche 'L. Sacco', Sezione di Malattie Infettive e Immunopatologia, Università degli Studi di Milano, Milano, Italy
| | - Alberto Gandolfi
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Roma, Italy
| | - Carmela Sinisgalli
- Istituto di Analisi dei Sistemi ed Informatica 'A. Ruberti' - CNR, Roma, Italy
| | - Claudia Balotta
- Dipartimento di Scienze Biomediche e Cliniche 'L. Sacco', Sezione di Malattie Infettive e Immunopatologia, Università degli Studi di Milano, Milano, Italy
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17
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Abstract
Drug resistance mutations emerge in genetic sequences of HIV through drug-selective pressure. Drug resistance can be transmitted. In this review we discuss phylogenetic methods used to study the emergence of drug resistance and the spread of resistant viruses.
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Affiliation(s)
- Anna Zhukova
- Unité Bioinformatique Evolutive, Centre de Bioinformatique, Biostatistique et Biologie Intégrative, C3BI USR 3756 Institut Pasteur et CNRS, France
| | | | - Olivier Gascuel
- Unité Bioinformatique Evolutive, Centre de Bioinformatique, Biostatistique et Biologie Intégrative, C3BI USR 3756 Institut Pasteur et CNRS, France
| | - Deenan Pillay
- Division of Infection and Immunity, University College London, United Kingdom.,Africa Health Research Institute, KwaZulu-Natal, South Africa
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18
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Shen M, Xiao Y, Rong L, Meyers LA, Bellan SE. Early antiretroviral therapy and potent second-line drugs could decrease HIV incidence of drug resistance. Proc Biol Sci 2017; 284:20170525. [PMID: 28659449 PMCID: PMC5489726 DOI: 10.1098/rspb.2017.0525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/26/2017] [Indexed: 11/12/2022] Open
Abstract
Early initiation of antiretroviral therapy (ART) reduces the risk of drug-sensitive HIV transmission but may increase the transmission of drug-resistant HIV. We used a mathematical model to estimate the long-term population-level benefits of ART and determine the scenarios under which earlier ART (treatment at 1 year post-infection, on average) could decrease simultaneously both total and drug-resistant HIV incidence (new infections). We constructed an infection-age-structured mathematical model that tracked the transmission rates over the course of infection and modelled the patients' life expectancy as a function of ART initiation timing. We fitted this model to the annual AIDS incidence and death data directly, and to resistance data and demographic data indirectly among men who have sex with men (MSM) in San Francisco. Using counterfactual scenarios, we assessed the impact on total and drug-resistant HIV incidence of ART initiation timing, frequency of acquired drug resistance, and second-line drug effectiveness (defined as the combination of resistance monitoring, biomedical drug efficacy and adherence). Earlier ART initiation could decrease the number of both total and drug-resistant HIV incidence when second-line drug effectiveness is sufficiently high (greater than 80%), but increase the proportion of new infections that are drug resistant. Thus, resistance may paradoxically appear to be increasing while actually decreasing.
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Affiliation(s)
- Mingwang Shen
- School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Yanni Xiao
- School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Libin Rong
- Department of Mathematics and Statistics, Oakland University, Rochester, MI 48309, USA
- Department of Mathematics, University of Florida, Gainesville, FL 32611, USA
| | - Lauren Ancel Meyers
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
- The Santa Fe Institute, Santa Fe, NM 87501, USA
| | - Steven E Bellan
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, GA 30602, USA
- Center for Ecology of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
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Filho AWDO, Brites C. Geolocalization of HIV-1 subtypes and resistance mutations of patients failing antiretroviral therapy in Salvador - Brazil. Braz J Infect Dis 2017; 21:234-239. [PMID: 28363087 PMCID: PMC9428007 DOI: 10.1016/j.bjid.2017.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 02/21/2017] [Accepted: 02/22/2017] [Indexed: 12/05/2022] Open
Abstract
Background Geographical distribution of HIV variants is an important way to understand the circulation and spread of such viral strains. Objectives To evaluate the spatial distribution of HIV-1 variants in patients failing antiretroviral therapy, in Salvador, Brazil. Methods We performed a cross-sectional evaluation of HIV resistance test reports of patients who underwent genotyping tests in a referral center in Salvador, Brazil, for the years 2008–2014. The laboratory database contains around 2500 resistance reports of patients failing antiretroviral therapy. Genotypic tests were performed by sequencing of HIV-1 POL region (TrueGene, Siemens). We assessed HIV-1 resistance mutations and subtype, as well as residential address, age, and gender of patients. Results We evaluated 1300 reports, 772 (59.4%) of them from male patients. As expected, subtype B predominated (79%) followed by subtypes F1 (6.7%) and BF (6.5%). The most frequent mutations in HIV-1 reverse transcriptase were 184V (79.1%), 41L (33.5%), 67N (30.4%), 103N (42.4%), and 108I (11.1%). Most frequent mutations in HIV-1 protease were 63P (52.4%), 36I (47.9%), 15 V (33.0%), 62 V (28.1%) and 13 V (25.8%). Some mutations (41L, 215Y, 210W) were significantly more frequent among men. We detected a significantly higher accumulation of 103N mutation in specific areas of Salvador. We identified a more restricted circulation pattern for subtype FB (more frequent in some regions), and F1 (almost absent in a specific region). Conclusion Our results suggest that specific subtypes/resistance mutations present a distinct frequency rate in specific areas of Salvador, probably due to a restricted circulation pattern. This trend to clustering was observed in regions covered by AIDS referral centers, suggesting that pattern of care for such patients can interfere in virological outcomes.
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Affiliation(s)
| | - Carlos Brites
- LAPI - Laboratório de Pesquisa em Infectologia, Faculdade de Medicina, Universidade Federal da Bahia, Salvador, BA, Brazil.
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20
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Wang Z, Zhang J, Li F, Ji X, Liao L, Ma L, Xing H, Feng Y, Li D, Shao Y. Drug resistance-related mutations T369V/I in the connection subdomain of HIV-1 reverse transcriptase severely impair viral fitness. Virus Res 2017; 233:8-16. [PMID: 28279801 DOI: 10.1016/j.virusres.2017.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/22/2017] [Accepted: 03/01/2017] [Indexed: 10/20/2022]
Abstract
Fitness is a key parameter in the measurement of transmission capacity of individual drug-resistant HIV. Drug-resistance related mutations (DRMs) T369V/I and A371V in the connection subdomain (CN) of reverse transcriptase (RT) occur at higher frequencies in the individuals experiencing antiretroviral therapy failure. Here, we evaluated the effects of T369V/I and A371V on viral fitness, in the presence or in the absence of thymidine analogue resistance-associated mutations (TAMs) and assessed the effect of potential RT structure-related mechanism on change in viral fitness. Mutations T369V/I, A371V, alone or in combination with TAMs were introduced into a modified HIV-1 infectious clone AT1 by site-directed mutagenesis. Then, experiments on mutant and wild-type virus AT2 were performed separately using a growth-competition assay, and then the relative fitness was calculated. Structural analysis of RT was conducted using Pymol software. Results showed that T369V/I severely impaired the relative virus fitness, and A371V compensated for the viral fitness reduction caused by TAMs. Structural modeling of RT suggests that T369V/I substitutions disrupt powerful hydrogen bonds formed by T369 and V365 in p51 and p66. This study indicates that the secondary DRMs within CN might efficiently damage viral fitness, and provides valuable information for clinical surveillance and prevention of HIV-1 strains carrying these DRMs.
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Affiliation(s)
- Zheng Wang
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China.
| | - Junli Zhang
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Fan Li
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Xiaolin Ji
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Lingjie Liao
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Liying Ma
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Hui Xing
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Yi Feng
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Dan Li
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Yiming Shao
- State Key Laboratory of Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of infectious Diseases, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Division of Research of Virology and Immunology, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China.
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Fofana MO, Shrestha S, Knight GM, Cohen T, White RG, Cobelens F, Dowdy DW. A Multistrain Mathematical Model To Investigate the Role of Pyrazinamide in the Emergence of Extensively Drug-Resistant Tuberculosis. Antimicrob Agents Chemother 2017; 61:e00498-16. [PMID: 27956422 DOI: 10.1128/AAC.00498-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 11/17/2016] [Indexed: 11/20/2022] Open
Abstract
Several infectious diseases of global importance—e.g., HIV infection and tuberculosis (TB)—require prolonged treatment with combination antimicrobial regimens typically involving high-potency core agents coupled with additional companion drugs that protect against the de novo emergence of mutations conferring resistance to the core agents. Often, the most effective (or least toxic) companion agents are reused in sequential (first-line, second-line, etc.) regimens. We used a multistrain model of Mycobacterium tuberculosis transmission in Southeast Asia to investigate how this practice might facilitate the emergence of extensive drug resistance, i.e., resistance to multiple core agents. We calibrated this model to regional TB and drug resistance data using an approximate Bayesian computational approach. We report the proportion of data-consistent simulations in which the prevalence of pre-extensively drug-resistant (pre-XDR) TB—defined as resistance to both first-line and second-line core agents (rifampin and fluoroquinolones)—exceeds predefined acceptability thresholds (1 to 2 cases per 100,000 population by 2035). The use of pyrazinamide (the most effective companion agent) in both first-line and second-line regimens increased the proportion of simulations in which the prevalence exceeded the pre-XDR acceptability threshold by 7-fold compared to a scenario in which patients with pyrazinamide-resistant TB received an alternative drug. Model parameters related to the emergence and transmission of pyrazinamide-resistant TB and resistance amplification were among those that were the most strongly correlated with the projected pre-XDR prevalence, indicating that pyrazinamide resistance acquired during first-line treatment subsequently promotes amplification to pre-XDR TB under pyrazinamide-containing second-line treatment. These findings suggest that the appropriate use of companion drugs may be critical to preventing the emergence of strains resistant to multiple core agents.
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Pham QD, Wilson DP, Nguyen TV, Do NT, Truong LX, Nguyen LT, Zhang L. Projecting the epidemiological effect, cost-effectiveness and transmission of HIV drug resistance in Vietnam associated with viral load monitoring strategies. J Antimicrob Chemother 2016; 71:1367-79. [PMID: 26869689 DOI: 10.1093/jac/dkv473] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 12/09/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The objective of this study was to investigate the potential epidemiological impact of viral load (VL) monitoring and its cost-effectiveness in Vietnam, where transmitted HIV drug resistance (TDR) prevalence has increased from <5% to 5%-15% in the past decade. METHODS Using a population-based mathematical model driven by data from Vietnam, we simulated scenarios of various combinations of VL testing coverage, VL thresholds for second-line ART initiation and availability of HIV drug-resistance tests. We assessed the cost per disability-adjusted life year (DALY) averted for each scenario. RESULTS Projecting expected ART scale-up levels, to approximately double the number of people on ART by 2030, will lead to an estimated 18 510 cases (95% CI: 9120-34 600 cases) of TDR and 55 180 cases (95% CI: 40 540-65 900 cases) of acquired drug resistance (ADR) in the absence of VL monitoring. This projection corresponds to a TDR prevalence of 16% (95% CI: 11%-24%) and ADR of 18% (95% CI: 15%-20%). Annual or biennial VL monitoring with 30% coverage is expected to relieve 12%-31% of TDR (2260-5860 cases), 25%-59% of ADR (9620-22 650 cases), 2%-6% of HIV-related deaths (360-880 cases) and 19 270-51 400 DALYs during 2015-30. The 30% coverage of VL monitoring is estimated to cost US$4848-5154 per DALY averted. The projected additional cost for implementing this strategy is US$105-268 million over 2015-30. CONCLUSIONS Our study suggests that a programmatically achievable 30% coverage of VL monitoring can have considerable benefits for individuals and leads to population health benefits by reducing the overall national burden of HIV drug resistance. It is marginally cost-effective according to common willingness-to-pay thresholds.
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Affiliation(s)
- Quang Duy Pham
- Disease Modelling and Financing Program, Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia Department for Disease Control and Prevention, Pasteur Institute, Ho Chi Minh City, Vietnam
| | - David P Wilson
- Disease Modelling and Financing Program, Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Thuong Vu Nguyen
- Department for Disease Control and Prevention, Pasteur Institute, Ho Chi Minh City, Vietnam
| | - Nhan Thi Do
- Department of HIV Care and Treatment, Vietnam Administration of HIV/AIDS Control, Hanoi, Vietnam
| | - Lien Xuan Truong
- Department of Laboratory Analysis, Pasteur Institute, Ho Chi Minh City, Vietnam
| | | | - Lei Zhang
- Disease Modelling and Financing Program, Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia Research Center for Public Health, School of Medicine, Tsinghua University, China Melbourne Sexual Health Centre, Alfred Health, Melbourne, Australia Central Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
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Milloy MJ, Wood E, Kerr T, Hogg B, Guillemi S, Harrigan PR, Montaner J. Increased Prevalence of Controlled Viremia and Decreased Rates of HIV Drug Resistance Among HIV-Positive People Who Use Illicit Drugs During a Community-wide Treatment-as-Prevention Initiative. Clin Infect Dis 2015; 62:640-7. [PMID: 26553011 DOI: 10.1093/cid/civ929] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 10/24/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Although treatment-as prevention (TasP) is a new cornerstone of global human immunodeficiency virus (HIV)-AIDS strategies, its effect among HIV-positive people who use illicit drugs (PWUD) has yet to be evaluated. We sought to describe longitudinal trends in exposure to antiretroviral therapy (ART), plasma HIV-1 RNA viral load (VL) and HIV drug resistance during a community-wide TasP intervention. METHODS We used data from the AIDS Care Cohort to Evaluate Exposure to Survival Services study, a prospective cohort of HIV-positive PWUD linked to HIV clinical monitoring records. We estimated longitudinal changes in the proportion of individuals with VL <50 copies/mL and rates of HIV drug resistance using generalized estimating equations (GEE) and extended Cox models. RESULTS Between 1 January 2006 and 30 June 2014, 819 individuals were recruited and contributed 1 or more VL observation. During that time, the proportion of individuals with nondetectable VL increased from 28% to 63% (P < .001). In a multivariable GEE model, later year of observation was independently and positively associated with greater likelihood of nondetectable VL (adjusted odds ratio = 1.20 per year; P < .001). Although the proportion of individuals on ART increased, the incidence of HIV drug resistance declined (adjusted hazard ratio = 0.78 per year; P = .011). CONCLUSIONS We observed significant improvements in several measures of exposure to ART and virologic status, including declines in HIV drug resistance, in this large long-running community-recruited cohort of HIV-seropositive illicit drug users during a community-wide ART expansion intervention. Our findings support continued efforts to scale up ART coverage among HIV-positive PWUD.
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Affiliation(s)
- M-J Milloy
- British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver
| | - Evan Wood
- British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver
| | - Thomas Kerr
- British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver
| | - Bob Hogg
- British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Silvia Guillemi
- British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital
| | - P Richard Harrigan
- British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver
| | - Julio Montaner
- British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver
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Abstract
In this research paper, our main objective is to find out the meticulous role of activated dendritic cells (DCs) during the human immunodeficiency virus (HIV) infection process. DCs play a dual role by enhancing both HIV infection progression, as well as antiviral immune response. To explore the implications of these dual roles, we have formulated our mathematical model and analyzed the model by both analytical and numerical approaches. By using an impulsive differential equation, we have studied the effect of DC-based vaccination. Analytically we have determined the threshold value of drug dosage and dosing interval for optimum levels of infection. We have also investigated the effect of perfect adherence of drug dose on the immune cell count in extreme cases and observed that, systematic drug dose of the immune cells leads to its maximum level.
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Affiliation(s)
- Priti Kumar Roy
- Center for Mathematical Biology and Ecology, Department of Mathematics, Jadavpur University, Kolkata 700032, India
| | - Amar Nath Chatterjee
- Center for Mathematical Biology and Ecology, Department of Mathematics, Jadavpur University, Kolkata 700032, India
| | - Xue-Zhi Li
- College of Mathematics and Information Science, Xinyang Normal University, Xinyang 464000, P. R. China
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Ke R, Loverdo C, Qi H, Sun R, Lloyd-Smith JO. Rational Design and Adaptive Management of Combination Therapies for Hepatitis C Virus Infection. PLoS Comput Biol 2015; 11:e1004040. [PMID: 26125950 PMCID: PMC4488346 DOI: 10.1371/journal.pcbi.1004040] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 11/13/2014] [Indexed: 12/17/2022] Open
Abstract
Recent discoveries of direct acting antivirals against Hepatitis C virus (HCV) have raised hopes of effective treatment via combination therapies. Yet rapid evolution and high diversity of HCV populations, combined with the reality of suboptimal treatment adherence, make drug resistance a clinical and public health concern. We develop a general model incorporating viral dynamics and pharmacokinetics/ pharmacodynamics to assess how suboptimal adherence affects resistance development and clinical outcomes. We derive design principles and adaptive treatment strategies, identifying a high-risk period when missing doses is particularly risky for de novo resistance, and quantifying the number of additional doses needed to compensate when doses are missed. Using data from large-scale resistance assays, we demonstrate that the risk of resistance can be reduced substantially by applying these principles to a combination therapy of daclatasvir and asunaprevir. By providing a mechanistic framework to link patient characteristics to the risk of resistance, these findings show the potential of rational treatment design.
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Affiliation(s)
- Ruian Ke
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail: (RK); (JOLS)
| | - Claude Loverdo
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, United States of America
- CNRS/UPMC Univ Paris 06, UMR 8237, Laboratoire Jean Perrin LJP, Paris, France
| | - Hangfei Qi
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Ren Sun
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, California, United States of America
- The Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Infectious Diseases, Novartis Institutes for BioMedical Research, Emeryville, California, United States of America
- Zhejiang University, Hangzhou, China
| | - James O. Lloyd-Smith
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (RK); (JOLS)
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Lad L, Clancy S, Koditek D, Wong MH, Jin D, Niedziela-Majka A, Papalia GA, Hung M, Yant S, Somoza JR, Hu E, Chou C, Tse W, Halcomb R, Sakowicz R, Pagratis N. Functional label-free assays for characterizing the in vitro mechanism of action of small molecule modulators of capsid assembly. Biochemistry 2015; 54:2240-8. [PMID: 25774576 DOI: 10.1021/acs.biochem.5b00151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
HIV capsid protein is an important target for antiviral drug design. High-throughput screening campaigns have identified two classes of compounds (PF74 and BI64) that directly target HIV capsid, resulting in antiviral activity against HIV-1 and HIV-2 laboratory strains. Using recombinant proteins, we developed a suite of label-free assays to mechanistically understand how these compounds modulate capsid activity. PF74 preferentially binds to the preassembled hexameric capsid form and prevents disruption of higher-order capsid structures by stabilizing capsid intersubunit interactions. BI64 binds only the monomeric capsid and locks the protein in the assembly incompetent monomeric form by disrupting capsid intersubunit interactions. We also used these assays to characterize the interaction between capsid and the host protein cleavage and polyadenylation specific factor 6 (CPSF6). Consistent with recently published results, our assays revealed CPSF6 activates capsid polymerization and preferentially binds to the preassembled hexameric capsid form similar to the small molecule compound, PF74. Furthermore, these label-free assays provide a robust method for facilitating the identification of a different class of small molecule modulators of capsid function.
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Affiliation(s)
- Latesh Lad
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Sheila Clancy
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - David Koditek
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Melanie H Wong
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Debi Jin
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | | | - Giuseppe A Papalia
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Magdeleine Hung
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Stephen Yant
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - John R Somoza
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Eric Hu
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Chienhung Chou
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Winston Tse
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Randall Halcomb
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Roman Sakowicz
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
| | - Nikos Pagratis
- Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, United States
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Gerberry DJ, Wagner BG, Garcia-Lerma JG, Heneine W, Blower S. Using geospatial modelling to optimize the rollout of antiretroviral-based pre-exposure HIV interventions in Sub-Saharan Africa. Nat Commun 2014; 5:5454. [PMID: 25462707 PMCID: PMC4322933 DOI: 10.1038/ncomms6454] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 10/02/2014] [Indexed: 11/18/2022] Open
Abstract
Antiretroviral-based pre-exposure HIV interventions may soon be rolled out in resource-constrained Sub-Saharan African countries, but rollout plans have yet to be designed. Here we use geospatial modeling and optimization techniques to compare two rollout plans for ARV-based microbicides in South Africa: a utilitarian plan that minimizes incidence by using geographic targeting, and an egalitarian plan that maximizes geographic equity in access to interventions. We find significant geographic variation in the efficiency of interventions in reducing HIV transmission, and that efficiency increases disproportionately with increasing incidence. The utilitarian plan would result in considerable geographic inequity in access to interventions, but (by exploiting geographic variation in incidence) could prevent ~40% more infections than the egalitarian plan. Our results show that the geographic resource allocation decisions made at the beginning of a rollout, and the location where the rollout is initiated, will be crucial in determining the success of interventions in reducing HIV epidemics.
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Affiliation(s)
- David J Gerberry
- Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California 90024, USA
| | - Bradley G Wagner
- Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California 90024, USA
| | - J Gerardo Garcia-Lerma
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30329, USA
| | - Walid Heneine
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30329, USA
| | - Sally Blower
- Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, California 90024, USA
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Pham QD, Wilson DP, Law MG, Kelleher AD, Zhang L. Global burden of transmitted HIV drug resistance and HIV-exposure categories: a systematic review and meta-analysis. AIDS 2014; 28:2751-62. [PMID: 25493601 DOI: 10.1097/QAD.0000000000000494] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVES Our aim was to review the global disparities of transmitted HIV drug resistance (TDR) in antiretroviral-naive MSM, people who inject drugs (PWID) and heterosexual populations in both high-income and low/middle-income countries. DESIGN/METHODS We undertook a systematic review of the peer-reviewed English literature on TDR (1999-2013). Random-effects meta-analyses were performed to pool TDR prevalence and compare the odds of TDR across at-risk groups. RESULTS A total of 212 studies were included in this review. Areas with greatest TDR prevalence were North America (MSM: 13.7%, PWID: 9.1%, heterosexuals: 10.5%); followed by western Europe (MSM: 11.0%, PWID: 5.7%, heterosexuals: 6.9%) and South America (MSM: 8.3%, PWID: 13.5%, heterosexuals: 7.5%). Our data indicated disproportionately high TDR burdens in MSM in Oceania (Australia 15.5%), eastern Europe/central Asia (10.2%) and east Asia (7.8%). TDR epidemics have stabilized in high-income countries, with a higher prevalence (range 10.9-12.6%) in MSM than in PWID (5.2-8.3%) and heterosexuals (6.4-9.0%) over 1999-2013. In low/middle-income countries, TDR prevalence in all at-risk groups in 2009-2013 almost doubled than that in 2004-2008 (MSM: 7.8 vs. 4.2%, P = 0.011; heterosexuals: 4.1 vs. 2.6%, P < 0.001; PWID: 4.8 vs. 2.4%, P = 0.265, respectively). The risk of TDR infection was significantly greater in MSM than that in heterosexuals and PWID. We observed increasing trends of resistance to non-nucleoside reverse transcriptase and protease inhibitors among MSM. CONCLUSION TDR prevalence is stabilizing in high-income countries, but increasing in low/middle-income countries. This is likely due to the low, but increasing, coverage of antiretroviral therapy in these settings. Transmission of TDR is most prevalent among MSM worldwide.
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de Lima-Stein ML, Alkmim WT, Bizinoto MCDS, Lopez LF, Burattini MN, Maricato JT, Giron L, Sucupira MCA, Diaz RS, Janini LM. In vivo HIV-1 hypermutation and viral loads among antiretroviral-naive Brazilian patients. AIDS Res Hum Retroviruses 2014; 30:867-80. [PMID: 25065371 DOI: 10.1089/aid.2013.0241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hypermutation alludes to an excessive number of specific guanine-to-adenine (G- >A) substitutions in proviral DNA and this phenomenon is attributed to the catalytic activity of cellular APOBECs. Population studies relating hypermutation and the progression of infection by human immunodeficiency virus type 1 (HIV-1) have been performed to elucidate the effect of hypermutation on the natural course of HIV-1 infection. However, the many different approaches employed to assess hypermutation in nucleotide sequences render the comparison of results difficult. This study selected 157 treatment-naive patients and sought to correlate the hypermutation level of the proviral sequences in clinical samples with demographic variables, HIV-1 RNA viral load, and the level of CD4(+) T cells. Nested touchdown polymerase chain reaction (PCR) was performed with specific primers to detect hypermutation in the region of HIV-1 integrase, and the amplified sequences were run in agarose gels with HA-Yellow. The analysis of gel migration patterns using the k-means clustering method was validated by its agreement with the results obtained with the software Hypermut. Hypermutation was found in 31.2% of the investigated samples, and a correlation was observed between higher hypermutation levels and higher viral load levels. These findings suggest a high frequency of hypermutation detection in a Brazilian cohort, which can reflect a particular characteristic of this population, but also can result from the method approach by aiming at hypermutation-sensitive sites. Furthermore, we found that hypermutation events are pervasive during HIV-1 infection as a consequence of high viral replication, reflecting its role during disease progression.
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Affiliation(s)
| | | | | | | | | | | | - Leila Giron
- Federal University of São Paulo, São Paulo, SP, Brazil
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31
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Lee GQ, Bangsberg DR, Muzoora C, Boum Y, Oyugi JH, Emenyonu N, Bennett J, Hunt PW, Knapp D, Brumme CJ, Harrigan PR, Martin JN. Prevalence and virologic consequences of transmitted HIV-1 drug resistance in Uganda. AIDS Res Hum Retroviruses 2014; 30:896-906. [PMID: 24960249 DOI: 10.1089/aid.2014.0043] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Few reports have examined the impact of HIV-1 transmitted drug resistance (TDR) in resource-limited settings where there are fewer regimen choices and limited pretherapy/posttherapy resistance testing. In this study, we examined TDR prevalence in Kampala and Mbarara, Uganda and assessed its virologic consequences after antiretroviral therapy initiation. We sequenced the HIV-1 protease/reverse transcriptase from n=81 and n=491 treatment-naive participants of the Uganda AIDS Rural Treatment Outcomes (UARTO) pilot study in Kampala (AMU 2002-2004) and main cohort in Mbarara (MBA 2005-2010). TDR-associated mutations were defined by the WHO 2009 surveillance mutation list. Posttreatment viral load data were available for both populations. Overall TDR prevalence was 7% (Kampala) and 3% (Mbarara) with no significant time trend. There was a slight but statistically nonsignificant trend indicating that the presence of TDR was associated with a worse treatment outcome. Virologic suppression (≤400 copies/ml within 6 months posttherapy initiation) was achieved in 87% and 96% of participants with wildtype viruses versus 67% and 83% of participants with TDR (AMU, MBA p=0.2 and 0.1); time to suppression (log-rank p=0.3 and p=0.05). Overall, 85% and 96% of study participants achieved suppression regardless of TDR status. Surprisingly, among the TDR cases, approximately half still achieved suppression; the presence of pretherapy K103N while on nevirapine and fewer active drugs in the first regimen were most often observed with failures. The majority of patients benefited from the local HIV care system even without resistance monitoring. Overall, TDR prevalence was relatively low and its presence did not always imply treatment failure.
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Affiliation(s)
| | - David R. Bangsberg
- Mbarara University of Science of Technology, Mbarara, Uganda
- Harvard Medical School, Boston, Massachusetts
- Harvard School of Public Health, Boston, Massachusetts
- Massachusetts General Hospital, Boston, Massachusetts
| | - Conrad Muzoora
- Mbarara University of Science of Technology, Mbarara, Uganda
| | - Yap Boum
- Mbarara University of Science of Technology, Mbarara, Uganda
| | - Jessica H. Oyugi
- University of California, San Francisco, California
- Independent consultant
| | - Nneka Emenyonu
- Mbarara University of Science of Technology, Mbarara, Uganda
| | - John Bennett
- University of California, San Francisco, California
| | | | - David Knapp
- B.C. Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
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Snedecor SJ, Sudharshan L, Nedrow K, Bhanegaonkar A, Simpson KN, Haider S, Chambers R, Craig C, Stephens J. Burden of nonnucleoside reverse transcriptase inhibitor resistance in HIV-1-infected patients: a systematic review and meta-analysis. AIDS Res Hum Retroviruses 2014; 30:753-68. [PMID: 24925216 PMCID: PMC4118702 DOI: 10.1089/aid.2013.0262] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The prevalence of HIV drug resistance varies with geographic location, year, and treatment exposure. This study generated yearly estimates of nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance in treatment-naive (TN) and treatment-experienced (TE) patients in the United States (US), Europe (EU), and Canada. Studies reporting NNRTI resistance identified in electronic databases and 11 conferences were analyzed in three groups: (1) TN patients in one of four geographic regions [US, Canada, EU countries with larger surveillance networks ("EU1"), and EU countries with fewer data ("EU2")]; (2) TE patients from any region; and (3) TN patients failing NNRTI-based treatments in clinical trials. Analysis data included 158 unique studies from 22 countries representing 84 cohorts of TN patients, 21 cohorts of TE patients, and 8 trials reporting resistance at failure. From 1995 to 2000, resistance prevalence in TN patients increased in US and EU1 from 3.1% to 7.5% and 0.8% to 3.6%, respectively. Resistance in both regions stabilized in 2006 onward. Little resistance was identified in EU2 before 2000, and increased from 2006 (5.0%) to 2010 (13.7%). One TN Canadian study was identified and reported resistance of 8.1% in 2006. Half of TN clinical trial patients had resistance after treatment failure at weeks 48-144. Resistance in TE patients increased from 1998 (10.1%) to 2001 (44.0%), then decreased after 2004. Trends in NNRTI resistance among TN patients show an increased burden in the US and some EU countries compared to others. These findings signify a need for alternate first-line treatments in some regions.
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Affiliation(s)
| | | | | | | | - Kit N. Simpson
- Medical University of South Carolina, Charleston, South Carolina
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Ross LL, Horton J, Hasan S, Brown JR, Murphy D, DeJesus E, Potter M, LaMarca A, Melendez-Rivera I, Ward D, Uy J, Shaefer MS. HIV-1 transmission patterns in antiretroviral therapy-naïve, HIV-infected North Americans based on phylogenetic analysis by population level and ultra-deep DNA sequencing. PLoS One 2014; 9:e89611. [PMID: 24586911 PMCID: PMC3935917 DOI: 10.1371/journal.pone.0089611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 01/22/2014] [Indexed: 11/18/2022] Open
Abstract
Factors that contribute to the transmission of human immunodeficiency virus type 1 (HIV-1), especially drug-resistant HIV-1 variants remain a significant public health concern. In-depth phylogenetic analyses of viral sequences obtained in the screening phase from antiretroviral-naïve HIV-infected patients seeking enrollment in EPZ108859, a large open-label study in the USA, Canada and Puerto Rico (ClinicalTrials.gov NCT00440947) were examined for insights into the roles of drug resistance and epidemiological factors that could impact disease dissemination. Viral transmission clusters (VTCs) were initially predicted from a phylogenetic analysis of population level HIV-1 pol sequences obtained from 690 antiretroviral-naïve subjects in 2007. Subsequently, the predicted VTCs were tested for robustness by ultra deep sequencing (UDS) using pyrosequencing technology and further phylogenetic analyses. The demographic characteristics of clustered and non-clustered subjects were then compared. From 690 subjects, 69 were assigned to 1 of 30 VTCs, each containing 2 to 5 subjects. Race composition of VTCs were significantly more likely to be white (72% vs. 60%; p = 0.04). VTCs had fewer reverse transcriptase and major PI resistance mutations (9% vs. 24%; p = 0.002) than non-clustered sequences. Both men-who-have-sex-with-men (MSM) (68% vs. 48%; p = 0.001) and Canadians (29% vs. 14%; p = 0.03) were significantly more frequent in VTCs than non-clustered sequences. Of the 515 subjects who initiated antiretroviral therapy, 33 experienced confirmed virologic failure through 144 weeks while only 3/33 were from VTCs. Fewer VTCs subjects (as compared to those with non-clustering virus) had HIV-1 with resistance-associated mutations or experienced virologic failure during the course of the study. Our analysis shows specific geographical and drug resistance trends that correlate well with transmission clusters defined by HIV sequences of similarity. Furthermore, our study demonstrates the utility of molecular and epidemiological analysis of VTCs for identifying population-specific risks associated with HIV-1 transmission and developing effective local healthcare strategies.
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Affiliation(s)
- Lisa L. Ross
- ViiV HealthCare, Research Triangle Park, North Carolina, United States of America
- * E-mail:
| | - Joseph Horton
- GlaxoSmithKline, Research Triangle Park, North Carolina, United States of America
| | | | - James R. Brown
- GlaxoSmithKline, Research Triangle Park, North Carolina, United States of America
| | | | - Edwin DeJesus
- Orlando Immunology Center, Orlando, Florida, United States of America
| | - Martin Potter
- McGill University Health Centre, Montreal, QC, Canada
| | - Anthony LaMarca
- Therafirst Medical Center, Ft Lauderdale, Florida, United States of America
| | | | - Douglas Ward
- Dupont Circle Physicians Group, Washington, DC, United States of America
| | - Jonathon Uy
- Amicus Therapeutics, Cranbury, New Jersey, United States of America
| | - Mark S. Shaefer
- ViiV HealthCare, Research Triangle Park, North Carolina, United States of America
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Nichols BE, Sigaloff KC, Kityo C, Mandaliya K, Hamers RL, Bertagnolio S, Jordan MR, Boucher CA, Rinke de Wit TF, van de Vijver DA. Averted HIV infections due to expanded antiretroviral treatment eligibility offsets risk of transmitted drug resistance: a modeling study. AIDS 2014; 28:73-83. [PMID: 23921620 DOI: 10.1097/01.aids.0000433239.01611.52] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Earlier antiretroviral therapy initiation can reduce the incidence of HIV-1. This benefit can be offset by increased transmitted drug resistance (TDR). We compared the preventive benefits of reducing incident infections with the potential TDR increase in East Africa. METHODS A mathematical model was constructed to represent Kampala, Uganda, and Mombasa, Kenya. We predicted the effect of initiating treatment at different immunological thresholds (<350, <500 CD4 cells/μl) on infections averted and mutation-specific TDR prevalence over 10 years compared to initiating treatment at CD4 cell count below 200 cells/μl. RESULTS When initiating treatment at CD4 cell count below 350 cells/μl, we predict 18 [interquartile range (IQR) 11-31] and 46 (IQR 30-83) infections averted for each additional case of TDR in Kampala and Mombasa, respectively, and 22 (IQR 17-35) and 32 (IQR 21-57) infections averted when initiating at below 500. TDR is predicted to increase most strongly when initiating treatment at CD4 cell count below 500 cells/μl, from 8.3% (IQR 7.7-9.0%) and 12.3% (IQR 11.7-13.1%) in 2012 to 19.0% (IQR 16.5-21.8%) and 19.2% (IQR 17.1-21.5%) in 10 years in Kampala and Mombasa, respectively. The TDR epidemic at all immunological thresholds was comprised mainly of resistance to non-nucleoside reverse transcriptase inhibitors. When 80-100% of individuals with virological failure are timely switched to second-line therapy, TDR is predicted to decline irrespective of treatment initiation threshold. CONCLUSION Averted HIV infections due to the expansion of antiretroviral treatment eligibility offset the risk of transmitted drug resistance, as defined by more infections averted than TDR gained. The effectiveness of first-line non-nucleoside reverse transcriptase inhibitor-based therapy can be preserved by improving switching practices to second-line therapy.
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Schneider K, Gray RT, Wilson DP. A cost-effectiveness analysis of HIV preexposure prophylaxis for men who have sex with men in Australia. Clin Infect Dis 2014; 58:1027-34. [PMID: 24385445 DOI: 10.1093/cid/cit946] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Antiretroviral therapy (ART) used as preexposure prophylaxis (PrEP) by human immunodeficiency virus (HIV)-seronegative individuals reduces the risk of acquiring HIV. However, the population-level impact and cost-effectiveness of using PrEP as a public health intervention remains debated. METHODS We used a stochastic agent-based model of HIV transmission and progression to simulate the clinical and cost outcomes of different strategies of providing PrEP to men who have sex with men (MSM) in New South Wales (NSW), Australia. Model outcomes were reported as incremental cost-effectiveness ratios (ICERs) in 2013 Australian dollars per quality-adjusted life-year gained (QALYG). RESULTS The use of PrEP in 10%-30% of the entire NSW MSM population was projected to cost an additional $316-$952 million over the course of 10 years, and cost >$400 000 per QALYG compared with the status quo. Targeting MSM with sexual partners ranging between >10 to >50 partners within 6 months cost an additional $31-$331 million dollars, and cost >$110 000 per QALYG compared with the status quo. We found that preexposure prophylaxis is most cost-effective when targeted for HIV-negative MSM in a discordant regular partnership. The ICERs ranged between $8399 and $11 575, for coverage ranging between 15% and 30%, respectively. CONCLUSIONS Targeting HIV-negative MSM in a discordant regular partnership is a cost-effective intervention. However, this highly targeted strategy would not have large population-level impact. Other scenarios are unlikely to be cost-effective.
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Affiliation(s)
- Karen Schneider
- The Kirby Institute for Infection and Immunity in Society, The University of New South Wales, Sydney, Australia
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Zhang H, Curreli F, Waheed AA, Mercredi PY, Mehta M, Bhargava P, Scacalossi D, Tong X, Lee S, Cooper A, Summers MF, Freed EO, Debnath AK. Dual-acting stapled peptides target both HIV-1 entry and assembly. Retrovirology 2013; 10:136. [PMID: 24237936 PMCID: PMC3842668 DOI: 10.1186/1742-4690-10-136] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 11/03/2013] [Indexed: 01/20/2023] Open
Abstract
Background Previously, we reported the conversion of the 12-mer linear and cell-impermeable peptide CAI to a cell-penetrating peptide NYAD-1 by using an i,i + 4 hydrocarbon stapling technique and confirmed its binding to the C-terminal domain (CTD) of the HIV-1 capsid (CA) protein with an improved affinity (Kd ~ 1 μM) compared to CAI (Kd ~ 15 μM). NYAD-1 disrupts the formation of both immature- and mature-like virus particles in in vitro and cell-based assembly assays. In addition, it displays potent anti-HIV-1 activity in cell culture against a range of laboratory-adapted and primary HIV-1 isolates. Results In this report, we expanded the study to i,i + 7 hydrocarbon-stapled peptides to delineate their mechanism of action and antiviral activity. We identified three potent inhibitors, NYAD-36, -66 and -67, which showed strong binding to CA in NMR and isothermal titration calorimetry (ITC) studies and disrupted the formation of mature-like particles. They showed typical α-helical structures and penetrated cells; however, the cell penetration was not as efficient as observed with the i,i + 4 peptides. Unlike NYAD-1, the i,i + 7 peptides did not have any effect on virus release; however, they impaired Gag precursor processing. HIV-1 particles produced in the presence of these peptides displayed impaired infectivity. Consistent with an effect on virus entry, selection for viral resistance led to the emergence of two mutations in the gp120 subunit of the viral envelope (Env) glycoprotein, V120Q and A327P, located in the conserved region 1 (C1) and the base of the V3 loop, respectively. Conclusion The i,i + 7 stapled peptides derived from CAI unexpectedly target both CA and the V3 loop of gp120. This dual-targeted activity is dependent on their ability to penetrate cells as well as their net charge. This mechanistic revelation will be useful in further modifying these peptides as potent anti-HIV-1 agents.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Asim K Debnath
- Laboratory of Molecular Modeling, Drug Design, Lindsley F, Kimball Research Institute of the New York Blood Center, 310 E 67th Street, New York, NY 10065, USA.
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Okano JT, Blower S. HIV treatment, preexposure prophylaxis, and drug resistance: reconciling conflicting predictions from mathematical models. J Infect Dis 2013; 209:163-4. [PMID: 24133183 DOI: 10.1093/infdis/jit544] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Justin T Okano
- Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles
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Sood N, Wagner Z, Jaycocks A, Drabo E, Vardavas R. Test-and-treat in Los Angeles: a mathematical model of the effects of test-and-treat for the population of men who have sex with men in Los Angeles County. Clin Infect Dis 2013; 56:1789-96. [PMID: 23487387 PMCID: PMC3658365 DOI: 10.1093/cid/cit158] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 02/06/2013] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND There is evidence to suggest that antiretroviral therapy (ART) and testing for human immunodeficiency virus (HIV) reduce the probability of transmission of HIV. This has led health officials across the United States to take steps toward a test-and-treat policy. However, the extent of the benefits generated by test-and-treat is debatable, and there are concerns, such as increased multidrug resistance (MDR), that remain unaddressed. METHODS We developed a deterministic epidemiologic model to simulate the HIV/AIDS epidemic for men who have sex with men (MSM) in Los Angeles County (LAC). We calibrated the model to match the HIV surveillance data from LAC across a 10-year period, starting in 2000. We then modified our model to simulate the test-and-treat policy and compared epidemiologic outcomes under the test-and-treat scenario to the status quo scenario over the years 2012-2023. Outcome measures included new infections, deaths, new AIDS cases, and MDR. RESULTS Relative to the status quo, the test-and-treat model resulted in a 34% reduction in new infections, 19% reduction in deaths, and 39% reduction in new AIDS cases by 2023. However, these results are counterbalanced by a near doubling of the prevalence of MDR (9.06% compared to 4.79%) in 2023. We also found that the effects of increasing testing and treatment were not complementary. CONCLUSIONS Although test-and-treat generates substantial benefits, it will not eliminate the epidemic for MSM in LAC. Moreover, these benefits are counterbalanced by large increases in MDR.
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Affiliation(s)
- Neeraj Sood
- Schaeffer Center for Health Policy and Economics
| | | | | | - Emmanuel Drabo
- Titus Family Department of Pharmaceutical Economics and Policy, University of Southern California, Los Angeles
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Abstract
PURPOSE OF REVIEW The declaration of the United Nations High Level meeting on AIDS in June 2011 includes 10 concrete targets, including to ensure that there are 15 million people living with human immunodeficiency virus (HIV) on antiretroviral treatment (ART) by 2015. This review examines the potential, opportunities and challenges of treatment as prevention of HIV and tuberculosis (TB) in reaching this target. RECENT FINDINGS Although around 8 million people are on treatment, everyone living with HIV will eventually need ART to stay alive. As many as 24 million people living with HIV today are not on treatment, the majority not even being aware of their HIV infection. Expansion of a comprehensive prevention strategy including providing ART to 15 million or more people would significantly reduce HIV and TB morbidity, mortality and transmission. The challenges include ensuring human rights protections, steady drug supply, early diagnosis and linkage to care, task shifting, adherence, retention, and monitoring and evaluation. Expansion could also lead to the control and possible elimination of HIV in many places. SUMMARY Achieving an 'AIDS-free generation' whereby deaths related to HIV are drastically reduced, people living with HIV are AIDS-free on ART, and HIV transmission is decreased, is both scientifically sound and practically feasible. The global community could reach 15 million people on ART by 2015 while expanding our vision and efforts to include diagnosis and treatment for all the 32 million people living with HIV in the future.
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Gonzalez-Serna A, Lima VD, Montaner JS, Harrigan PR, Brumme CJ. "Test-and-treat" strategy for control of HIV and AIDS can lead to a decrease, not an increase, of multidrug-resistant viruses. Clin Infect Dis 2013; 57:478-9. [PMID: 23625937 DOI: 10.1093/cid/cit257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sanchez TW, Debnath B, Christ F, Otake H, Debyser Z, Neamati N. Discovery of novel inhibitors of LEDGF/p75-IN protein-protein interactions. Bioorg Med Chem 2013; 21:957-63. [PMID: 23306052 PMCID: PMC6188659 DOI: 10.1016/j.bmc.2012.12.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 11/25/2012] [Accepted: 12/03/2012] [Indexed: 11/30/2022]
Abstract
Human lens epithelium-derived growth factor (LEDGF)/p75 plays an important role in the HIV life cycle by stimulating integrase (IN)-led viral DNA integration into cellular chromosomes. Mechanistic studies show the majority of IN inhibitors chelate magnesium ions in the catalytic active site, a region topologically distant from the LEDGF/p75 binding site. Compounds disrupting the formation of LEDGF/p75 and IN complexes serve as a novel mechanistic approach different from current antiretroviral therapies. We previously built pharmacophore models mimicking LEDGF/p75 residues and identified four classes of LEDGF/p75-IN inhibitors. Substructure and similarity searches yielded additional LEDGF/p75-IN inhibitors containing an acylhydrazone moiety. The most potent of the acylhydrazones inhibited LEDGF/p75-IN interaction with an IC(50) value of 400nM. We explored structure-activity relationships (SAR) and identified new acylhydrazones, hydrazines, and diazenes as lead molecules for further optimization. Two lead LEDGF/p75-IN inhibitors showed antiviral activity.
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Affiliation(s)
- Tino Wilson Sanchez
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
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Saenz RA, Bonhoeffer S. Nested model reveals potential amplification of an HIV epidemic due to drug resistance. Epidemics 2012; 5:34-43. [PMID: 23438429 DOI: 10.1016/j.epidem.2012.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 11/07/2012] [Accepted: 11/08/2012] [Indexed: 12/24/2022] Open
Abstract
The use of antiretroviral therapy (ART) is the most efficient measure in controlling the HIV epidemic. However, emergence of drug-resistant strains can reduce the potential benefits of ART. The viral dynamics of drug-sensitive and drug-resistant strains at the individual level may play a crucial role in the emergence and spread of drug resistance in a population. We investigate the effect of the viral dynamics within an infected individual on the epidemiological dynamics of HIV using a nested model that links both dynamical levels. A time-dependent between-host transmission rate that receives feedback from a model of two-strain virus dynamics within a host is incorporated into an epidemiological model of HIV. We analyze the resulting dynamics of the model and identify model parameters such as time when ART is initiated, fraction of cases treated, and the probability that a patient develops drug resistance, as having the greatest impact on total infection and prevalence of drug resistance. Importantly, for small values of the risk of a patient developing drug resistance, increasing the fraction of cases treated can increase the cumulative number of infected individuals. Such a pattern is the result of the balance between not treating a patient and having future cases still sensitive to treatment, and treating the patient and increasing the chances for future (untreatable) drug-resistant infections. The current modeling framework incorporates important aspects of virus dynamics within a host into an epidemic model. This approach provides useful insights on the drug resistance dynamics of an epidemic of HIV, which may assist in identifying an optimal use of ART.
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Affiliation(s)
- Roberto A Saenz
- Institute of Integrative Biology, ETH Zurich, ETH-Zentrum CHN, 8092 Zurich, Switzerland
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Wagner BG, Blower S. Universal access to HIV treatment versus universal 'test and treat': transmission, drug resistance & treatment costs. PLoS One 2012; 7:e41212. [PMID: 22957012 PMCID: PMC3434222 DOI: 10.1371/journal.pone.0041212] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 06/18/2012] [Indexed: 11/18/2022] Open
Abstract
In South Africa (SA) universal access to treatment for HIV-infected individuals in need has yet to be achieved. Currently ∼1 million receive treatment, but an additional 1.6 million are in need. It is being debated whether to use a universal ‘test and treat’ (T&T) strategy to try to eliminate HIV in SA; treatment reduces infectivity and hence transmission. Under a T&T strategy all HIV-infected individuals would receive treatment whether in need or not. This would require treating 5 million individuals almost immediately and providing treatment for several decades. We use a validated mathematical model to predict impact and costs of: (i) a universal T&T strategy and (ii) achieving universal access to treatment. Using modeling the WHO has predicted a universal T&T strategy in SA would eliminate HIV within a decade, and (after 40 years) cost ∼$10 billion less than achieving universal access. In contrast, we predict a universal T&T strategy in SA could eliminate HIV, but take 40 years and cost ∼$12 billion more than achieving universal access. We determine the difference in predictions is because the WHO has under-estimated survival time on treatment and ignored the risk of resistance. We predict, after 20 years, ∼2 million individuals would need second-line regimens if a universal T&T strategy is implemented versus ∼1.5 million if universal access is achieved. Costs need to be realistically estimated and multiple evaluation criteria used to compare ‘treatment as prevention’ with other prevention strategies. Before implementing a universal T&T strategy, which may not be sustainable, we recommend striving to achieve universal access to treatment as quickly as possible. We predict achieving universal access to treatment would be a very effective ‘treatment as prevention’ approach and bring the HIV epidemic in SA close to elimination, preventing ∼4 million infections after 20 years and ∼11 million after 40 years.
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Affiliation(s)
| | - Sally Blower
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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Abstract
Antiviral agents can be used to prevent HIV transmission before exposure as preexposure prophylaxis (PrEP), after exposure as postexposure prophylaxis, and as treatment of infected people for secondary prevention. Considerable research has shed new light on antiviral agents for PrEP and for prevention of secondary HIV transmission. While promising results have emerged from several PrEP trials, the challenges of poor adherence among HIV-negative clients and possible increase in sexual risk behaviors remain a concern. In addition, a broader pipeline of antiviral agents for PrEP that focuses on genital tract pharmacology and safety and resistance issues must be developed. Antiretroviral drugs have also been used to prevent HIV transmission from HIV-infected patients to their HIV-discordant sexual partners. The HIV Prevention Trials Network 052 trial demonstrated nearly complete prevention of HIV transmission by early treatment of infection, but the generalizability of the results to other risk groups - including intravenous drug users and MSM - has not been determined. Most importantly, the best strategy for use of antiretroviral agents to reduce the spread of HIV at either the individual level or the population level has not been developed, and remains the ultimate goal of this area of investigation.
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Affiliation(s)
- Myron S. Cohen
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Kathryn E. Muessig
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - M. Kumi Smith
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Kimberly A. Powers
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Angela D.M. Kashuba
- School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
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Burchell AN, Bayoumi AM, Rourke SB, Major C, Gardner S, Sandstrom P, Rachlis A, Taylor D, Mazzulli T, Fisher M, Brooks J. Increase in transmitted HIV drug resistance among persons undergoing genotypic resistance testing in Ontario, Canada, 2002-09. J Antimicrob Chemother 2012; 67:2755-65. [PMID: 22833637 DOI: 10.1093/jac/dks287] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.
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Hill AL, Rosenbloom DIS, Nowak MA. Evolutionary dynamics of HIV at multiple spatial and temporal scales. J Mol Med (Berl) 2012; 90:543-61. [PMID: 22552382 PMCID: PMC7080006 DOI: 10.1007/s00109-012-0892-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/24/2012] [Accepted: 03/07/2012] [Indexed: 11/28/2022]
Abstract
Infectious diseases remain a formidable challenge to human health, and understanding pathogen evolution is crucial to designing effective therapeutics and control strategies. Here, we review important evolutionary aspects of HIV infection, highlighting the concept of selection at multiple spatial and temporal scales. At the smallest scale, a single cell may be infected by multiple virions competing for intracellular resources. Recombination and phenotypic mixing introduce novel evolutionary dynamics. As the virus spreads between cells in an infected individual, it continually evolves to circumvent the immune system. We discuss evolutionary mechanisms of HIV pathogenesis and progression to AIDS. Viral spread throughout the human population can lead to changes in virulence and the transmission of immune-evading variation. HIV emerged as a human pathogen due to selection occurring between different species, adapting from related viruses of primates. HIV also evolves resistance to antiretroviral drugs within a single infected host, and we explore the possibility for the spread of these strains between hosts, leading to a drug-resistant epidemic. We investigate the role of latency, drug-protected compartments, and direct cell-to-cell transmission on viral evolution. The introduction of an HIV vaccine may select for viral variants that escape vaccine control, both within an individual and throughout the population. Due to the strong selective pressure exerted by HIV-induced morbidity and mortality in many parts of the world, the human population itself may be co-evolving in response to the HIV pandemic. Throughout the paper, we focus on trade-offs between costs and benefits that constrain viral evolution and accentuate how selection pressures differ at different levels of selection.
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Affiliation(s)
- Alison L Hill
- Program for Evolutionary Dynamics, Department of Mathematics, Harvard University, Cambridge, MA 02138, USA.
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Wagner BG, Garcia-Lerma JG, Blower S. Factors limiting the transmission of HIV mutations conferring drug resistance: fitness costs and genetic bottlenecks. Sci Rep 2012; 2:320. [PMID: 22432052 DOI: 10.1038/srep00320] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 02/20/2012] [Indexed: 11/08/2022] Open
Abstract
Transmission of HIV strains with drug-resistance mutations (DRMs) causes public health problems in resource-rich countries. We use a stochastic model, with data from viral competition experiments, to analyze the effect of fitness costs (FCs) and genetic bottlenecks on limiting transmission of 10 clinically significant DRMs. Transmission of DRMs with low FCs (∼0.2%) is similar to wild-type; transmission chains last ∼8 generations causing clusters of ∼60 infected individuals. Genetic bottlenecks substantially limit transmission of DRMs with moderately high FCs (∼0.6%); chains last ∼1–3 generations with transmission clusters of 2–7. Transmission of DRMs with extremely high FCs (>6%) only occurs from ∼5% of index cases. DRMs can revert to wild-type and remain as minority strains, within treatment-naïve individuals, undetectable by current resistance assays. We calculate, based on assay sensitivity, the length of time each DRM is detectable within individuals. Taken together, our results imply a hidden epidemic of transmitted resistance may exist.
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Kahn JG, Marseille EA, Bennett R, Williams BG, Granich R. Cost-effectiveness of antiretroviral therapy for prevention. Curr HIV Res 2012; 9:405-15. [PMID: 21999776 PMCID: PMC3529401 DOI: 10.2174/157016211798038542] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 08/04/2011] [Accepted: 08/12/2011] [Indexed: 12/24/2022]
Abstract
Recent empirical studies and analyses have heightened interest in the use of expanded antiretroviral therapy (ART) for prevention of HIV transmission. However, ART is expensive, approximately $600 per person per year, raising issues of the cost and cost-effectiveness of ambitious ART expansion. The goal of this review is to equip the reader with the conceptual tools and substantive background needed to understand and evaluate the policy and programmatic implications of cost-effectiveness assessments of ART for prevention. We provide this review in six sections. We start by introducing and explaining basic concepts of health economics as they relate to this issue, including resources, costs, health metrics (such as Disability-Adjusted Life Years), and different types of economic analysis. We then review research on the cost and cost-effectiveness of ART as treatment, and on the cost-effectiveness of traditional HIV prevention. We describe critical issues in the epidemic impact of ART, such as suppression of transmission and the role of the acute phase of infection. We then present a conceptual model for conducting and interpreting cost-effectiveness analyses of ART as prevention, and review the existing preliminary estimates in this area. We end with a discussion of future directions for programmatic demonstrations and evaluation.
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Granich R, Kahn JG, Bennett R, Holmes CB, Garg N, Serenata C, Sabin ML, Makhlouf-Obermeyer C, De Filippo Mack C, Williams P, Jones L, Smyth C, Kutch KA, Ying-Ru L, Vitoria M, Souteyrand Y, Crowley S, Korenromp EL, Williams BG. Expanding ART for treatment and prevention of HIV in South Africa: estimated cost and cost-effectiveness 2011-2050. PLoS One 2012; 7:e30216. [PMID: 22348000 PMCID: PMC3278413 DOI: 10.1371/journal.pone.0030216] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2011] [Accepted: 12/12/2011] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Antiretroviral Treatment (ART) significantly reduces HIV transmission. We conducted a cost-effectiveness analysis of the impact of expanded ART in South Africa. METHODS We model a best case scenario of 90% annual HIV testing coverage in adults 15-49 years old and four ART eligibility scenarios: CD4 count <200 cells/mm(3) (current practice), CD4 count <350, CD4 count <500, all CD4 levels. 2011-2050 outcomes include deaths, disability adjusted life years (DALYs), HIV infections, cost, and cost per DALY averted. Service and ART costs reflect South African data and international generic prices. ART reduces transmission by 92%. We conducted sensitivity analyses. RESULTS Expanding ART to CD4 count <350 cells/mm(3) prevents an estimated 265,000 (17%) and 1.3 million (15%) new HIV infections over 5 and 40 years, respectively. Cumulative deaths decline 15%, from 12.5 to 10.6 million; DALYs by 14% from 109 to 93 million over 40 years. Costs drop $504 million over 5 years and $3.9 billion over 40 years with breakeven by 2013. Compared with the current scenario, expanding to <500 prevents an additional 585,000 and 3 million new HIV infections over 5 and 40 years, respectively. Expanding to all CD4 levels decreases HIV infections by 3.3 million (45%) and costs by $10 billion over 40 years, with breakeven by 2023. By 2050, using higher ART and monitoring costs, all CD4 levels saves $0.6 billion versus current; other ART scenarios cost $9-194 per DALY averted. If ART reduces transmission by 99%, savings from all CD4 levels reach $17.5 billion. Sensitivity analyses suggest that poor retention and predominant acute phase transmission reduce DALYs averted by 26% and savings by 7%. CONCLUSION Increasing the provision of ART to <350 cells/mm3 may significantly reduce costs while reducing the HIV burden. Feasibility including HIV testing and ART uptake, retention, and adherence should be evaluated.
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Affiliation(s)
- Reuben Granich
- HIV/AIDS Department, World Health Organization, Geneva, Switzerland.
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Shah PS, Pham NP, Schaffer DV. HIV develops indirect cross-resistance to combinatorial RNAi targeting two distinct and spatially distant sites. Mol Ther 2012; 20:840-8. [PMID: 22294151 DOI: 10.1038/mt.2012.3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Resistance to existing HIV therapies is an increasing problem, and alternative treatments are urgently needed. RNA interference (RNAi), an innate mechanism for sequence-specific gene silencing, can be harnessed therapeutically to treat viral infections, yet viral resistance can still emerge. Here, we demonstrate that HIV can develop indirect resistance to individual and combinatorial RNAi-targeting protein-coding regions up to 5,500 nucleotides (nt) downstream of the viral promoter. We identify several variants harboring mutations in the HIV promoter, and not within the RNAi targets, that produce more fully elongated transcripts. Furthermore, these variants are resistant to the RNAi, potentially by stoichiometrically overwhelming this cellular mechanism. Alarmingly, virus resistant to one short hairpin RNA (shRNA) also exhibits cross-resistance to a different shRNA, which targets a distinct and spatially distant region to which the virus has not been previously exposed. To our knowledge, this is the first example of HIV "cross-resistance" to viral inhibitors targeting different loci. Finally, combining anti-HIV RNAi with a small molecule enhancer of RNAi can inhibit the replication of an indirectly resistant mutant. These results suggest that indirect resistance to RNAi is a general mechanism that should be considered when investigating viral resistance and designing combinatorial RNAi therapies.
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