Tracing the multiple concurrent partner debate

As the debate heats up about whether or not multiple concurrent partnerships (MCPs) are major drivers of Africa’s HIV epidemics, IRIN/PlusNews takes a look at the evolution of the theory behind MCPs.

1982 - Uganda diagnoses its first case of HIV along the shores of Lake Victoria.

1986 - Uganda's civil war ends and the country establishes its first national HIV prevention programme which incorporates the message of “zero grazing” aimed at encouraging faithfulness and partner reduction - effectively the world’s first MCP campaign.

1992 - British epidemiologists Robert May and Charlotte Watts propose that long-term simultaneous partnerships might increase the spread of HIV.

Also around this time, Christopher Hudson becomes interested in concurrency while treating sexually transmitted infections in London. He hypothesizes that MCPs may explain the high prevalence of briefly infectious STIs such as gonorrhea among some groups of his clients. He hypothesizes that if clients had stayed in long-term, monogamous relationships, short-lived infections would have died out within these London communities. The lingering presence of the disease in some sexual networks could be explained by people infected with gonorrhea having multiple partners during their brief periods of infectivity.

1993 - Researcher Martina Morris, drawing on the hypothesis that Africa’s high HIV rates were fuelled by “high risk” populations, such sex workers and truck drivers, develops a mathematical model to predict the spread of HIV in a population and travels to Uganda to test it out. Upon arrival in the country, she meets local doctors who quickly convince her that the model would be irrelevant unless it could take into account the effect of MCPs. Morris collects the sexual histories of more than 1,000 Ugandans, charting not only the number of sexual partners but also concurrency. Around 35 percent of re spondents said that at least two of their most recent relationships had overlapped by several months or years. She later conducts similar research in Thailand and the USA. 

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She later teams up with the mathematician Mirjam Kretzschmar to develop a new model that could compare the spread of HIV through two hypothetical populations: one in which concurrent partnerships were common and another in which serial monogamy was the norm. They found that HIV spread 10 times faster in the first population.

2003 - US President George W. Bush launches the President's Emergency Plan for AIDS Relief (PEPFAR) which places a strong emphasis on abstinence based on the assumption that HIV is spreading mainly through casual sex among youth rather than through longer-term relationships among older people. Uganda expands HIV prevention in schools with US funding. Known as the Presidential Initiative on AIDS Strategy for Communication to Youth (PIASCY), the campaign advocates abstinence-until-marriage.

2004 - Anthrpologist Daniel T. Halperin, and author and scientist Helen Epstein publish their first paper on MCPs in The Lancet Medical journal.

2006 - At a 2006 Southern African Development Community (SADC) meeting in Maseru, Lesotho, MCPs are identified as a key driver of the region's HIV epidemic, along with low levels of male circumcision and inconsistent condom use.

2008 - HIV prevalence in Uganda begins to rise, according to UNAIDS, which in its yearly report notes that new HIV infections are highest among people in long-term relationships where one or both partners have other sexual relationships at the same time.

Meanwhile, MCPs become a key focus of HIV programmes in eastern and southern Africa aimed at achieving a reduction in infections through widespread behaviour change. Campaigns include OneLove, a regional effort rolled out in nine southern African countries.

2009 - A heated debate begins between proponents of the MCP theory, such as Halperin and Epstein, and detractors like US-based social epidemiologist Mark Lurie and public health researcher Samantha Rosenthal, and continues to rage in academic journals.