Definition of Discordant couple

A pair of long-term sexual partners in which one has a sexually transmitted infection and the other does not. In the case of HIV/AIDS, one partner is positive and the other is negative.

The following is taken from a Report from the Mail & Guardian

“Silas Masindi was not entirely surprised by his HIV test results. The dapper garment trader, who discovered earlier this year that he was infected with the Aids virus, admits to using condoms somewhat erratically before he remarried three years ago.

“I would meet a girl, use a condom, but after four months stop using them,” he says.

But surprisingly his second wife, Grace, does not have the virus. The pair have joined other couples who have a mismatched HIV status, something also known as HIV discordance.

Between 13% and 36% of couples in South Africa may be in discordant relationships, says Dr Sinead Delany-Moretlwe of the reproductive health and HIV unit at the University of the Witwatersrand.

However, researchers have yet to understand fully why the Aids virus is not transmitted between these partners, even when they fail to practise safe sex.
“It’s such a new concept, even medical people are baffled by it,” says Dr Mamazane Maduna, also with the unit.


What scientists do know is that HIV discordance is related to a combination of factors that include:

  • genetics,
  • HI-virus type,
  • the extent to which the infection has progressed in the HIV-positive partner,
  • other sexually transmitted diseases and
  • circumcision — which research indicates may reduce the risk of HIV infection.

“The virus is not systematically transmitted at each and every sexual encounter and depends on how far the HIV-positive person is in the progression of his condition,” says Zimbabwe-based Dr Alexander Boon of the Spanish chapter of the NGO Doctors Without Borders.

A study is under way in six African countries, in a bid to unravel the mysteries of HIV discordance.  Conducted in partnership with the University of Washington with funding from the Bill and Melinda Gates Foundation, the study is being carried out at 13 sites in South Africa, Botswana, Kenya, Uganda, Zambia and Rwanda.

South Africa has three sites, one at Orange Farm, a sprawling informal settlement located just south of Johannesburg. Since the programme began in August last year, 314 couples have been tested there, 80 of which were HIV discordant. Thirty-seven of the discordant couples are now participating in trials.

As biological and social factors are known to increase women’s vulnerability to HIV, the assumption might be that it is typically the man in discordant relationships who is HIV-negative. However, HIV infection occurred equally among men and women in discordant relationships who were tested at Orange Farm.”