The number of new HIV infections diagnosed in Ireland last year was up by 10 per cent to 399, according to figures just released.
The National Disease Surveillance Centre (NDSC) said some 221 (55 per cent) were heterosexually acquired, compared to 232 the previous year.
However, the NDSC warned that the data must be interpreted with caution as information on risk groups is unavailable for 39 of the newly diagnosed cases last year, making analysis of the trends difficult.
Some 196 (49 per cent) of those diagnosed with HIV in 2003 were female and 202 were male. Nearly four out of five (79 per cent) of these cases were in 20- to 40-year-olds.
Almost half (199) of the diagnosed cases of HIV in 2003 were among people born in sub-Saharan Africa, while 133 of those diagnosed were borne in Ireland. Information on geographic origin was unavailable for 41 cases.
There were 75 new diagnoses among men who have sex with men (MSMs) during 2003, compared with 46 for the previous year.
There were 47 new diagnoses among injecting drug users during 2003 compared to 50 in 2002.
NDSC specialist in public health medicine Dr Mary Cronin said the number of infections among MSMs is likely to reflect an increase in risky sexual behaviour in this group.
"Increases in risky sexual behaviour, HIV and other sexually transmitted infections have been reported from Western Europe. The number of diagnoses in people born in sub-Saharan Africa mirrors the epidemiology of HIV in other Western European countries and is not unexpected, given that 70 per cent of the world's HIV cases are found in sub Saharan Africa," she said.
"It is important to note that these figures do not represent the number of people infected with the HIV virus in Ireland, but rather provide information on the number of new diagnoses in 2003. The number of new diagnoses reported is dependent on patterns of HIV testing and reporting."
Dr Cronin said the figures highlight the continuing need for appropriate prevention and treatment services for all risk groups, including migrants and their communities.
Fine Gael's health spokeswoman, Ms Olivia Mitchell, said the increase in HIV cases indicated an immediate need to make HIV a notifiable disease.
"The already overstretched health service can only plan accordingly if it knows the extent of the problem and the numbers requiring treatment. HIV sufferers themselves also deserve and need something better than an ad hocand unplanned service," she said.
"Most important of all, the general public need and deserve to know that HIV is still out there, that it is a threat and that, like other STIs, it is on the increase."
Ms Mitchell said the Government had taken far too relaxed an approach to this critical public health issue and was in danger of losing control of the problem. Information campaigns against casual unsafe sex disappeared once the introduction of anti-retroviral drugs meant HIV was no longer a "certain killer", she added.