Rise in HIV diagnoses in Northern Ireland
The number of people diagnosed with HIV in Northern Ireland has increased by almost a fifth.
Last year, 95 new cases of the virus were confirmed, most among homosexual men.
It is no longer a death sentence for patients who get the best care and drugs.
The infection is incurable, although taking a daily dose of medication can keep it in check, producing a near-normal life expectancy.
Dr Neil Irvine, a consultant at the Public Health Agency (PHA), said many others may be carrying HIV without knowing it.
"There is evidence of some sexually transmitted infections increasing, that would be an indication of unsafe sex happening," he said.
A concurrent increase in diseases like syphilis also suggests the amount of risky behaviour is on the rise.
The expert in health protection added: "People have either forgotten that safer sex message or they don't see it as being relevant to them, or that they are at risk.
"There is maybe a bit of the ostrich mentality."
A report from the PHA said the number of new diagnoses of HIV made in Northern Ireland increased by 17% from 81 in 2011 to 95 last year.
Of those, 58% occurred in men who have sex with men.
A total of 639 infected residents received care last year.
The virus, which destroys the immune system as a precursor to AIDS and potentially life-threatening illnesses like pneumonia, is transmitted through sexual contact; sharing contaminated needles and syringes, and transmission from mother to child before, during or shortly after birth.
According to animal studies published recently in the journal Nature, a potential new HIV treatment has an unprecedented impact.
Potent antibodies wiped a mixture of human and monkey immunodeficiency viruses from the bloodstream of monkeys within days.
Today is World AIDS Day.
Globally, an estimated 34 million people have HIV.
Dr Michael McBride, chief medical officer, said today was an opportunity to raise awareness, reduce stigma and improve education.
He helped launch a new HIV pregnancy internet programme from Queen's University Belfast.
"Mother to child transmission of HIV infection can be greatly reduced through early diagnosis of maternal HIV infection, early intervention and proper ante-natal and post-natal care," he said.
"Understanding the needs of HIV-positive women who are considering family planning is the first step to preventing this mode of HIV infection."