Gender asymmetry in concurrent partnerships and HIV prevalence.
The structure of the sexual network of a population plays an essential role in the transmission of HIV. Concurrent partnerships, i.e. partnerships that overlap in time, are important in determining this network structure. Men and women may differ in their concurrent behavior, e.g. in the case of polygyny where women are monogamous while men may have concurrent partnerships. Polygyny has been shown empirically to be negatively associated with HIV prevalence, but the epidemiological impacts of other forms of gender-asymmetric concurrency have not been formally explored. Here we investigate how gender asymmetry in concurrency, including polygyny, can affect the disease dynamics. We use a model for a dynamic network where individuals may have concurrent partners. The maximum possible number of simultaneous partnerships can differ for men and women, e.g. in the case of polygyny. We control for mean partnership duration, mean lifetime number of partners, mean degree, and sexually active lifespan. We assess the effects of gender asymmetry in concurrency on two epidemic phase quantities (R0and the contribution of the acute HIV stage to R0) and on the endemic HIV prevalence. We find that gender asymmetry in concurrent partnerships is associated with lower levels of all three epidemiological quantities, especially in the polygynous case. This effect on disease transmission can be attributed to changes in network structure, where increasing asymmetry leads to decreasing network connectivity.
Utrecht University, PO Box 80010, 3508 TA Utrecht, The Netherlands; University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands. Electronic address: kayin.leung@math.su.se.
Ka Yin
KY
Leung
The University of North Carolina at Chapel Hill, 2105D McGavran-Greenberg Hall, Campus Box 7435, Chapel Hill, NC 27599-7435, USA. Electronic address: powersk@email.unc.edu.
Kimberly A
KA
Powers
University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands; National Institute of Public Health and the Environment, PO Box 1, 3720 BA Bilthoven, The Netherlands. Electronic address: m.e.e.kretzschmar@umcutrecht.nl.
Mirjam
M
Kretzschmar
D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D058872:Epidemics / Q000706:statistics & numerical data; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008393:Marriage / Q000706:statistics & numerical data*; D008875:Middle Aged; D015995:Prevalence; D017678:Sex Distribution; D012747:Sexual Partners; D055815:Young Adult
Concurrency; Gender asymmetry; HIV prevalence; Mathematical model; Polygyny