Condom resistance remains a real problem among HIV discordant couples in Uganda, new research has found.

The study, whose results were presented at the 15th conference on retroviruses and opportunistic infections in Boston, Massachusetts, found that of  36,000 couples tested, 96 percent of those in sexually active discordant relationships (where only one partner is HIV positive) reported not using condoms during their last sexual encounter.

"The people we studied were in stable relationships - usually man and wife - and thus they did not feel the need to use condoms," said Dr Elioda Tumwesigye, the lead researcher. "Even after testing, many continued to practice unprotected sex, saying that discordance was fate or that one partner must be immune."

The research was as a result of a United States Centers for Disease Control (CDC) initiative to provide home-based voluntary counselling and testing to 250,000 people in in the western district of Bushenyi between 2004 and 2006.

Tumwesigye added that knowledge of HIV prevention was high in the community, but people felt condoms did not belong in the marital bed.

The men in the Bushenyi sample were more likely to be infected than the women, something Tumwesigye said was likely to be as a result of the age difference between men and women in the couples; on average, women were 30 years old while their spouses had a median age of 40.

"It's possible that these older men, with more sexual experience and higher exposure to HIV, married young girls with relatively little sexual experience," he said. "It is important to send a strong message to these couples that condoms will protect them and their relationships."

He noted that it was particularly urgent because in the study, discordant couples represented over 60 percent of the couples in which one or both partners was HIV-positive.

According to James Kigozi, spokesman for the Uganda AIDS Commission, resistance to and inconsistent use of condoms is a pattern replicated across the country.

"It is a real challenge trying to get married couples to use condoms because of the way they are perceived, as a tool for single people," he said.

"We routinely encourage couples to come for testing together but usually only the women come as part of their ante-natal care; if they test negative their husbands will feel like they too must then be negative and thus won't come," he added. "Another challenge is that women are often not in apposition to negotiate safer sex, so they continue to be put at risk in discordant relationships."

Kigozi said the government was using radio programmes, billboards and other media to encourage couples to jointly test. CDC's home-based care initiative in Bushenyi is also using radio and home visits to pass on the importance of VCT and condom use in discordant relationships.

The HIV/AIDS sero-behavioural survey of 2004-5 found that about five percent of about 4,000 cohabiting couples in Uganda were discordant. An estimated three percent of the couples were both HIV-positive.