Age-dependent partnering and the HIV transmission chain: a microsimulation analysis

Efficient planning and evaluation of human immunodeficiency virus (HIV) prevention programmes requires an understanding of what sustains the epidemic, including the mechanism by which HIV transmission keeps pace with the ageing of the infected population. Recently, more detailed population models have been developed which represent the epidemic with sufficient detail to characterize the dynamics of ongoing transmission. Here, we describe the structure and parameters of such a model, called EMOD-HIV v. 0.7. We analyse the chains of transmission that allow the HIV epidemic to propagate across age groups in this model. In order to prevent the epidemic from dying out, the virus must find younger victims faster than its extant victims age and die. The individuals who enable such transmission events in EMOD-HIV v. 0.7 are higher concurrency, co-infected males aged 26–29 and females aged 23–24. Prevention programmes that target these populations could efficiently interrupt the mechanisms that allow HIV to transmit at a pace that is faster than the progress of time.

[1]  Shalini Santhakumaran,et al.  Polygyny and symmetric concurrency: comparing long-duration sexually transmitted infection prevalence using simulated sexual networks , 2010, Sexually Transmitted Infections.

[2]  A. Walker,et al.  Age as a determinant of survival in HIV infection. , 2001, Journal of clinical epidemiology.

[3]  Michael Rayment,et al.  Prevention of HIV-1 infection with early antiretroviral therapy , 2012, Journal of Family Planning and Reproductive Health Care.

[4]  D. Pillay,et al.  Effect on transmission of HIV-1 resistance of timing of implementation of viral load monitoring to determine switches from first to second-line antiretroviral regimens in resource-limited settings , 2011, AIDS.

[5]  Daniel J. Klein.  Relationship formation and flow control algorithms for generating age-structured networks in HIV modeling , 2012, 2012 IEEE 51st IEEE Conference on Decision and Control (CDC).

[6]  Connie Celum,et al.  Heterosexual HIV-1 transmission after initiation of antiretroviral therapy: a prospective cohort analysis , 2010, The Lancet.

[7]  R. Baltussen,et al.  Frequency of CXCR4-using viruses in primary HIV-1 infections using ultra-deep pyrosequencing , 2011, AIDS.

[8]  James D. Campbell,et al.  Antiretroviral prophylaxis for HIV prevention in heterosexual men and women. , 2012, The New England journal of medicine.

[9]  D. Cooper,et al.  Second-line combination antiretroviral therapy in resource-limited settings: facing the challenges through clinical research , 2007, AIDS.

[10]  HOMAS,et al.  VIRAL LOAD AND HETEROSEXUAL TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE 1 VIRAL LOAD AND HETEROSEXUAL TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE 1 , 2000 .

[11]  Jim Todd,et al.  Time from HIV seroconversion to death: a collaborative analysis of eight studies in six low and middle-income countries before highly active antiretroviral therapy , 2007, AIDS.

[12]  Jeffrey W. Eaton,et al.  HIV Treatment as Prevention: Systematic Comparison of Mathematical Models of the Potential Impact of Antiretroviral Therapy on HIV Incidence in South Africa , 2012, PLoS medicine.

[13]  Matthias Egger,et al.  Sexual transmission of HIV according to viral load and antiretroviral therapy: systematic review and meta-analysis , 2009, AIDS.

[14]  A. Matthews,et al.  Fitting the HIV Epidemic in Zambia: A Two-Sex Micro-Simulation Model , 2009, PloS one.

[15]  S. Vermund,et al.  Transitioning HIV care and treatment programs in southern Africa to full local management. , 2012, AIDS.

[16]  R. Baltussen,et al.  The Impact of the New WHO Antiretroviral Treatment Guidelines on HIV Epidemic Dynamics and Cost in South Africa , 2011, PloS one.

[17]  N. Sewankambo,et al.  Survival of HIV-infected treatment-naive individuals with documented dates of seroconversion in Rakai, Uganda , 2007, AIDS.

[18]  John T Brooks,et al.  Antiretroviral preexposure prophylaxis for heterosexual HIV transmission in Botswana. , 2012, The New England journal of medicine.