A new report indicates that 44 per cent of new HIV infections nationwide in heterosexual relationships are transmitted among HIV discordant couples.
Discordant couples are partners in which one partner is infected and the other is not.
The Kenyan Aids Indicator Survey 2012 report also indicates that 260,000 married and cohabiting couples were HIV discordant, making treatment for HIV positive partners in such relationships an essential component of Kenya's HIV prevention strategy.
According to the report among married couples 4.8 per cent were HIV discordant and the treatment of an HIV infected partner reduces the likelihood of passing HIV to the uninfected partner.
In about half of all discordant couples, the male partners were the HIV infected partner, while the other half was the female infected partner.
The study revealed that 72 per cent of women in the discordant relationships accurately knew their male partner were HIV positive compared to 58 per cent of the men who knew the status of their female partners.
The majority of the HIV both concordant positive and HIV discordant couples reside in Nyanza region where the virus is prevalent at 15.1 per cent.
"Over 55.9 per cent of all concordant HIV infected and 34.3 per cent of all male infected and 31.1 per cent of all female infected discordant couples live in the same region," reads part of the report.
Rift Valley South also has a high percentage of couples affected by HIV with 11.9 per cent of all concordant HIV infected couples, 12.3 per cent of all male infected discordant couples and 11.8 per cent of all female discordant couples.
However, Nairobi and Eastern South regions have the largest percentages of male discordant couples with 20.5 per cent and 15.5 per cent of all male infected discordant couple.
About two thirds of concordant HIV infected and concordant HIV uninfected couples reside in rural settings. But among HIV discordant couples, slightly more live in urban areas.
"In HIV discordant couples in which the female was infected, 57.2 per cent lived in urban areas while HIV discordant couples in which the female was infected 51.1 per cent lived in urban areas," read part of the report.
In knowledge and disclosure of HIV status more than half at 53.1 per cent of persons found to be having the virus did not know there status.
A greater proportion of men than women were unaware of their infection at 61.9 and 47.8 per cent respectively.
The report also indicated that 53.5 per cent of persons reported that they were aware of their partners' HIV status but only about 57.7 per cent of these had correct knowledge of their partners' actual HIV infection based on laboratory results.
Among all HIV infected persons in the KAIS 2012 report, 46.9 per cent self-reported positive based on their last HIV test.
This was an improvement from KAIS 2007 when only 16 per cent of HIV infected persons had correct knowledge of their HIV positive status.
The proportion of HIV infected men who correctly knew their HIV status increased with age from 23.1 per cent among men aged 25-29 years to 49 per cent among men aged 40-44 years.