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Silhol R, Coupland H, Baggaley RF, Miller L, Staadegaard L, Gottlieb SL, Stannah J, Turner KME, Vickerman P, Hayes R, Mayaud P, Looker KJ, Boily MC. What Is the Burden of Heterosexually Acquired HIV Due to HSV-2? Global and Regional Model-Based Estimates of the Proportion and Number of HIV Infections Attributable to HSV-2 Infection. J Acquir Immune Defic Syndr 2021; 88:19-30. [PMID: 34117163 PMCID: PMC8397258 DOI: 10.1097/qai.0000000000002743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 05/20/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Biological and epidemiological evidence suggest that herpes simplex virus type 2 (HSV-2) elevates HIV acquisition and transmission risks. We improved previous estimates of the contribution of HSV-2 to HIV infections by using a dynamic transmission model. SETTING World Health Organization regions. METHODS We developed a mathematical model of HSV-2/HIV transmission among 15- to 49-year-old heterosexual, non-drug-injecting populations, calibrated using region-specific demographic and HSV-2/HIV epidemiological data. We derived global and regional estimates of the contribution of HSV-2 to HIV infection over 10 years [the transmission population-attributable fraction (tPAF)] under 3 additive scenarios, assuming: (1) HSV-2 increases only HIV acquisition risk (conservative); (2) HSV-2 also increases HIV transmission risk (liberal); and (3) HIV or antiretroviral therapy (ART) also modifies HSV-2 transmission risk, and HSV-2 decreases ART effect on HIV transmission risk (fully liberal). RESULTS Under the conservative scenario, the predicted tPAF was 37.3% (95% uncertainty interval: 33.4%-43.2%), and an estimated 5.6 (4.5-7.0) million incident heterosexual HIV infections were due to HSV-2 globally over 2009-2018. The contribution of HSV-2 to HIV infections was largest for the African region [tPAF = 42.6% (38.0%-51.2%)] and lowest for the European region [tPAF = 11.2% (7.9%-13.8%)]. The tPAF was higher among female sex workers, their clients, and older populations, reflecting their higher HSV-2 prevalence. The tPAF was approximately 50% and 1.3- to 2.4-fold higher for the liberal or fully liberal scenario than the conservative scenario across regions. CONCLUSION HSV-2 may have contributed to at least 37% of incident HIV infections in the past decade worldwide, and even more in Africa, and may continue to do so despite increased ART access unless future improved HSV-2 control measures, such as vaccines, become available.
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Affiliation(s)
- Romain Silhol
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London
| | - Helen Coupland
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London
| | - Rebecca F. Baggaley
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London
- Department of Respiratory Sciences, University of Leicester
| | - Lori Miller
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Lisa Staadegaard
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London
| | - Sami L. Gottlieb
- Department of Sexual and Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | - James Stannah
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montréal (QC), Canada
| | | | - Peter Vickerman
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Richard Hayes
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Philippe Mayaud
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Katharine J. Looker
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Marie-Claude Boily
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London
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Spicknall IH, Looker KJ, Gottlieb SL, Chesson HW, Schiffer JT, Elmes J, Boily MC. Review of mathematical models of HSV-2 vaccination: Implications for vaccine development. Vaccine 2018; 37:7396-7407. [PMID: 29625767 PMCID: PMC6892260 DOI: 10.1016/j.vaccine.2018.02.067] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 02/12/2018] [Indexed: 10/25/2022]
Abstract
Development of a vaccine against herpes simplex virus type 2 (HSV-2), a life-long sexually-transmitted infection (STI), would be a major step forward in improving global sexual and reproductive health. In this review, we identified published literature of dynamic mathematical models assessing the impact of either prophylactic or therapeutic HSV-2 vaccination at the population level. We compared each study's model structure and assumptions as well as predicted vaccination impact. We examined possible causes of heterogeneity across model predictions, key gaps, and the implications of these findings for future modelling efforts. Only eight modelling studies have assessed the potential public health impact of HSV-2 vaccination, with the majority focusing on impact of prophylactic vaccines. The studies showed that even an imperfect prophylactic HSV-2 vaccine could have an important public health impact on HSV-2 incidence, and could also impact HIV indirectly in high HIV prevalence settings. Therapeutic vaccines also may provide public health benefits, though they have been explored less extensively. However, there was substantial variation in predicted population-level impact for both types of vaccine, reflecting differences in assumptions between model scenarios. Importantly, many models did not account for heterogeneity in infection rates such as by age, sex and sexual activity. Future modelling work to inform decisions on HSV vaccine development and implementation should consider cost-effectiveness, account for additional HSV-2 sequelae such as neonatal transmission, and model greater heterogeneity in infection rates between individuals, more realistic vaccine deployment, and more thorough sensitivity and uncertainty analyses.
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Affiliation(s)
- Ian H Spicknall
- Division of STD Prevention, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA.
| | - Katharine J Looker
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Sami L Gottlieb
- Department of Reproductive Health and Research, World Health Organization (WHO), Geneva, Switzerland
| | - Harrell W Chesson
- Division of STD Prevention, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
| | - Joshua T Schiffer
- University of Washington, Seattle, WA, USA; Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Jocelyn Elmes
- Department of Infectious Diseases Epidemiology, Imperial College London, UK
| | - Marie-Claude Boily
- Department of Infectious Diseases Epidemiology, Imperial College London, UK
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Ragupathy V, Xue W, Tan J, Devadas K, Gao Y, Hewlett I. Progesterone augments cell susceptibility to HIV-1 and HIV-1/HSV-2 co-infections. J Mol Endocrinol 2016; 57:185-99. [PMID: 27538988 DOI: 10.1530/jme-16-0138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 08/18/2016] [Indexed: 01/09/2023]
Abstract
In human immunodeficiency virus type 1 (HIV-1)-infected women, oral or injectable progesterone containing contraceptive pills may enhance HIV-1 acquisition in vivo, and the mechanism by which this occurs is not fully understood. In developing countries, Herpes simplex virus type-2 (HSV-2) co-infection has been shown to be a risk for increase of HIV-1 acquisition and, if co-infected women use progesterone pills, infections may increase several fold. In this study, we used an in vitro cell culture system to study the effects of progesterone on HIV-1 replication and to explore the molecular mechanism of progesterone effects on infected cells. In our in vitro model, CEMss cells (lymphoblastoid cell line) were infected with either HIV-1 alone or co-infected with HSV-2. HIV-1 viral load was measured with and without sex hormone treatment. Progesterone-treated cells showed an increase in HIV-1 viral load (1411.2 pg/mL) compared with cells without progesterone treatment (993.1 pg/mL). Increased cell death was noted with HSV-2 co-infection and in progesterone-treated cells. Similar observations were noted in peripheral blood mononuclear cells (PBMC) cells derived from three female donors. Progesterone-treated cells also showed reduced antiviral efficacy. Inflammatory cytokines and associations with biomarkers of disease progression were explored. Progesterone upregulated inflammatory cytokines and chemokines conversely and downregulated anti-apoptotic Bcl-2 expression. Nuclear protein analysis by electrophoretic mobility shift assay showed the association of progesterone with progesterone response element (PRE), which may lead to downregulation of Bcl-2. These data indicate that progesterone treatment enhances HIV-1 replication in infected cells and co-infection with HSV-2 may further fuel this process.
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Affiliation(s)
- Viswanath Ragupathy
- Lab of Molecular VirologyDivision of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Wang Xue
- Lab of Molecular VirologyDivision of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Ji Tan
- Lab of Molecular VirologyDivision of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Krishnakumar Devadas
- Lab of Molecular VirologyDivision of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Yamei Gao
- Division of Viral ProductsCenter for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Indira Hewlett
- Lab of Molecular VirologyDivision of Emerging Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
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A model for the coupled disease dynamics of HIV and HSV-2 with mixing among and between genders. Math Biosci 2015; 265:82-100. [PMID: 25953482 DOI: 10.1016/j.mbs.2015.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/20/2015] [Accepted: 04/24/2015] [Indexed: 11/23/2022]
Abstract
Evidence indicates that those with genital herpes (HSV-2) infections have greater risks of infection by HIV; and, once co-infected, are more likely to transmit HIV. To better understand the interactions between HIV and HSV-2, we construct a mathematical model that describes the joint dynamics. A new feature of this model is the inclusion of both heterosexual and homosexual interactions. We derive and interpret the basic and invasion reproduction numbers for HIV and HSV-2 using the approach of next-generation matrices. We then perform scenario analyses and conduct a sensitivity analysis to investigate the impact of the model parameters on the reproduction numbers and disease prevalences. We conclude that homosexual transmission drastically changes the disease prevalences; hence, it is important to account for this interaction as models that ignore homosexuality may greatly underestimate the disease burden.
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Terris-Prestholt F, Foss AM, Cox AP, Heise L, Meyer-Rath G, Delany-Moretlwe S, Mertenskoetter T, Rees H, Vickerman P, Watts CH. Cost-effectiveness of tenofovir gel in urban South Africa: model projections of HIV impact and threshold product prices. BMC Infect Dis 2014; 14:14. [PMID: 24405719 PMCID: PMC3899035 DOI: 10.1186/1471-2334-14-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 12/24/2013] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND There is urgent need for effective HIV prevention methods that women can initiate. The CAPRISA 004 trial showed that a tenofovir-based vaginal microbicide had significant impact on HIV incidence among women. This study uses the trial findings to estimate the population-level impact of the gel on HIV and HSV-2 transmission, and price thresholds at which widespread product introduction would be as cost-effective as male circumcision in urban South Africa. METHODS The estimated 'per sex-act' HIV and HSV-2 efficacies were imputed from CAPRISA 004. A dynamic HIV/STI transmission model, parameterised and fitted to Gauteng (HIV prevalence of 16.9% in 2008), South Africa, was used to estimate the impact of gel use over 15 years. Uptake was assumed to increase linearly to 30% over 10 years, with gel use in 72% of sex-acts. Full economic programme and averted HIV treatment costs were modelled. Cost per DALY averted is estimated and a microbicide price that equalises its cost-effectiveness to that of male circumcision is estimated. RESULTS Using plausible assumptions about product introduction, we predict that tenofovir gel use could lead to a 12.5% and 4.9% reduction in HIV and HSV-2 incidence respectively, by year 15. Microbicide introduction is predicted to be highly cost-effective (under $300 per DALY averted), though the dose price would need to be just $0.12 to be equally cost-effective as male circumcision. A single dose or highly effective (83% HIV efficacy per sex-act) regimen would allow for more realistic threshold prices ($0.25 and $0.33 per dose, respectively). CONCLUSIONS These findings show that an effective coitally-dependent microbicide could reduce HIV incidence by 12.5% in this setting, if current condom use is maintained. For microbicides to be in the range of the most cost-effective HIV prevention interventions, product costs will need to decrease substantially.
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Xiridou M, Vriend HJ, Lugner AK, Wallinga J, Fennema JS, Prins JM, Geerlings SE, Rijnders BJA, Prins M, de Vries HJC, Postma MJ, van Veen MG, Schim van der Loeff MF, van der Sande MAB. Modelling the impact of chlamydia screening on the transmission of HIV among men who have sex with men. BMC Infect Dis 2013; 13:436. [PMID: 24047261 PMCID: PMC3851177 DOI: 10.1186/1471-2334-13-436] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 09/16/2013] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Recent studies have found high prevalences of asymptomatic rectal chlamydia among HIV-infected men who have sex with men (MSM). Chlamydia could increase the infectivity of HIV and the susceptibility to HIV infection. We investigate the role of chlamydia in the spread of HIV among MSM and the possible impact of routine chlamydia screening among HIV-infected MSM at HIV treatment centres on the incidence of chlamydia and HIV in the overall MSM population. METHODS A mathematical model was developed to describe the transmission of HIV and chlamydia among MSM. Parameters relating to sexual behaviour were estimated from data from the Amsterdam Cohort Study among MSM. Uncertainty analysis was carried out for model parameters without confident estimates. The effects of different screening strategies for chlamydia were investigated. RESULTS Among all new HIV infections in MSM, 15% can be attributed to chlamydia infection. Introduction of routine chlamydia screening every six months among HIV-infected MSM during regular HIV consultations can reduce the incidence of both infections among MSM: after 10 years, the relative percentage reduction in chlamydia incidence would be 15% and in HIV incidence 4%, compared to the current situation. Chlamydia screening is more effective in reducing HIV incidence with more frequent screening and with higher participation of the most risky MSM in the screening program. CONCLUSIONS Chlamydia infection could contribute to the transmission of HIV among MSM. Preventive measures reducing chlamydia prevalence, such as routine chlamydia screening of HIV-infected MSM, can result in a decline in the incidence of chlamydia and HIV.
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Affiliation(s)
- Maria Xiridou
- National Institute of Public Health and Environment, P.O. Box 1, 3720, BA Bilthoven, the Netherlands
| | - Henrike J Vriend
- National Institute of Public Health and Environment, P.O. Box 1, 3720, BA Bilthoven, the Netherlands
- Department of Internal Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| | - Anna K Lugner
- National Institute of Public Health and Environment, P.O. Box 1, 3720, BA Bilthoven, the Netherlands
| | - Jacco Wallinga
- National Institute of Public Health and Environment, P.O. Box 1, 3720, BA Bilthoven, the Netherlands
| | - Johannes S Fennema
- STI Outpatient Clinic, Public Health Service of Amsterdam, Amsterdam, the Netherlands
| | - Jan M Prins
- Department of Internal Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| | - Suzanne E Geerlings
- Department of Internal Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| | - Bart JA Rijnders
- Department of Internal Medicine and Infectious Diseases, Erasmus University Medical Centre, Rotterdam, the Netherlands
| | - Maria Prins
- Department of Internal Medicine, Academic Medical Centre, Amsterdam, the Netherlands
- Research Department, Public Health Service of Amsterdam, Amsterdam, the Netherlands
| | - Henry JC de Vries
- National Institute of Public Health and Environment, P.O. Box 1, 3720, BA Bilthoven, the Netherlands
- STI Outpatient Clinic, Public Health Service of Amsterdam, Amsterdam, the Netherlands
- Department of Dermatology, Academic Medical Centre, Amsterdam, the Netherlands
| | - Maarten J Postma
- Department of Pharmacy, University of Groningen, Groningen, the Netherlands
| | - Maaike G van Veen
- STI Outpatient Clinic, Public Health Service of Amsterdam, Amsterdam, the Netherlands
| | - Maarten F Schim van der Loeff
- Department of Internal Medicine, Academic Medical Centre, Amsterdam, the Netherlands
- Research Department, Public Health Service of Amsterdam, Amsterdam, the Netherlands
| | - Marianne AB van der Sande
- National Institute of Public Health and Environment, P.O. Box 1, 3720, BA Bilthoven, the Netherlands
- Julius Center, University Medical Centre, Utrecht, the Netherlands
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Semaan S, Leinhos M, Neumann MS. Public health strategies for prevention and control of HSV-2 in persons who use drugs in the United States. Drug Alcohol Depend 2013; 131:182-97. [PMID: 23647730 DOI: 10.1016/j.drugalcdep.2013.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 03/21/2013] [Accepted: 03/21/2013] [Indexed: 02/06/2023]
Abstract
BACKGROUND Herpes simplex virus type 2 (HSV-2) affects HIV acquisition, transmission, and disease progression. Effective medications for genital herpes and for HIV/AIDS exist. Parenteral transmission of HIV among persons who inject drugs is decreasing. Reducing sexual transmission of HIV and HSV-2 among persons who use drugs (PWUD; i.e., heroin, cocaine, "speedball", crack, methamphetamine through injection or non-injection) necessitates relevant services. METHODS We reviewed HSV-2 sero-epidemiology and HSV-2/HIV associations in U.S.-based studies with PWUD and the general literature on HSV-2 prevention and treatment published between 1995 and 2012. We used the 6-factor Kass framework to assess relevant HSV-2 public health strategies and services in terms of their goals and effectiveness; identification of, and minimization of burdens and concerns; fair implementation; and fair balancing of benefits, burdens, and concerns. RESULTS Eleven studies provided HSV-2 serologic test results. High HSV-2 sero-prevalence (range across studies 38-75%) and higher sero-prevalence in HIV-infected PWUD (97-100% in females; 61-74% in males) were reported. Public health strategies for HSV-2 prevention and control in PWUD can include screening or testing; knowledge of HSV-2 status and partner disclosure; education, counseling, and psychosocial risk-reduction interventions; treatment for genital herpes; and HIV antiretroviral medications for HSV-2/HIV co-infected PWUD. CONCLUSIONS HSV-2 sero-prevalence is high among PWUD, necessitating research on development and implementation of science-based public health interventions for HSV-2 infection and HSV-2/HIV co-infections, including research on effectiveness and cost-effectiveness of such interventions, to inform development and implementation of services for PWUD.
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Affiliation(s)
- Salaam Semaan
- Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Office of the Director, 1600 Clifton Road, NE, E-07, Atlanta, GA 30333, United States.
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Feng Z, Qiu Z, Sang Z, Lorenzo C, Glasser J. Modeling the synergy between HSV-2 and HIV and potential impact of HSV-2 therapy. Math Biosci 2013; 245:171-87. [PMID: 23850537 DOI: 10.1016/j.mbs.2013.07.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 06/28/2013] [Accepted: 07/02/2013] [Indexed: 11/27/2022]
Abstract
Mounting evidence indicates that genital HSV-2 infection may increase susceptibility to HIV infection and that co-infection may increase infectiousness. Accordingly, antiviral treatment of people with HSV-2 may mitigate the incidence of HIV in populations where both pathogens occur. To better understand the epidemiological synergy between HIV and HSV-2, we formulate a deterministic compartmental model that describes the transmission dynamics of these pathogens. Unlike earlier models, ours incorporates gender and heterogeneous mixing between activity groups. We derive explicit expressions for the reproduction numbers of HSV-2 and HIV, as well as the invasion reproduction numbers via next generation matrices. A qualitative analysis of the system includes the local and global behavior of the model. Simulations reinforce these analytical results and demonstrate epidemiological synergy between HSV-2 and HIV. In particular, numerical results show that HSV-2 favors the invasion of HIV, may dramatically increase the peak as well as reducing the time-to-peak of HIV prevalence, and almost certainly has exacerbated HIV epidemics. The potential population-level impact of HSV-2 on HIV is demonstrated by calculating the fraction of HIV infections attributable to HSV-2 and the difference between HIV prevalence in the presence and absence of HSV-2. The potential impact of treating people with HSV-2 on HIV control is demonstrated by comparing HIV prevalence with and without HSV-2 therapy. Most importantly, we illustrate that the aforementioned aspects of the population dynamics can be significantly influenced by the sexual structure of the population.
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Affiliation(s)
- Zhilan Feng
- Department of Mathematics, Nanjing University of Information Science and Technology, Nanjing 210044, PR China; Department of Mathematics, Purdue University, West Lafayette, IN 47907, USA.
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