Some 5,805 people are living with the HIV/Aids virus in Ireland according to the Health Service Executive (HSE).
To mark World Aids Day toady the executive has launched a sexual health awareness campaign to help combat STIs (sexually transmitted infections).
Figures released by the Health Protection Surveillance Centre (HPSC) found in the first half of this year 168 new cases of HIV were diagnosed in Ireland compared to 209 in 2009 and 186 in 2008, the executive said.
Men accounted for 123 new cases (73 per cent) and women 44 cases (26 per cent).
Where the route of transmission was reported the centre said approximately 45 per cent of all new cases were among men who had sex with men, 40 per cent were heterosexual and almost 12 per cent were through intravenous drug use.
The HSE campaign, which will especially target men as they account for biggest increase in new cases, aims to promote condom use to prevent sexually transmitted infections.