The annual number of people newly diagnosed with HIV infection has risen for the fifth year in a row.
Last year, 224 cases of human immunodeficiency virus infection were recorded, up from 217 in 2014, according to data published today by Otago University's Aids epidemiology group.
In 2011, there were 109 cases, the lowest annual tally since the early 2000s, and in the 1990s it was mostly below 100.
By contrast, the number of new Aids cases recorded each year continues its generally downward trend from a peak of around 70 in the late 1980s/early 1990s, to nine last year.
Men who have sex with men (MSM) continue to be the largest proportion of those diagnosed with HIV, which has been the case in most years since the records on the epidemic began in New Zealand in the 1980s.
Of those diagnosed with HIV last year, 153 (68 per cent) were MSM, and 42 (19 per cent) were heterosexually infected men and women.
Four people were infected through injecting drugs and one child was infected overseas, having been born to a woman with undiagnosed HIV.
HIV can lead to Aids (acquired immune deficiency syndrome); a person with Aids is vulnerable to diseases such as some cancers and pneumonia.
"Of particular concern is that the number of MSM diagnosed and infected in New Zealand continues at the high rate seen in 2014," said the epidemiology group's director, Associate Professor Nigel Dickson.
He said that although regular HIV testing of those at risk was important, people with HIV were most infectious to their sexual partners for several months after becoming infected, so condom use was essential to prevent acquiring and spreading HIV, even among those whose last test was negative.
The rising annual number of HIV infections indicated all possible methods of preventing the spread of the disease should be considered.
"Internationally, many countries now fund anti-retroviral treatment for all people with HIV -- whatever their level of immune deficiency -- to reduce their infectivity," said Professor Dickson.
Some were even considering providing the treatment as a preventive measure -- to uninfected people at high risk of catching HIV. Trials had shown this was effective in reducing the risk of acquiring HIV, said Professor Dickson.
About half of people who acquired HIV heterosexually in New Zealand last year were infected in this country, the rest overseas.
• 224 people were diagnosed with HIV infection last year
• 205 men
• 18 women
• 1 transgender woman
• HIV (human immunodeficiency virus) can lead to Aids (acquired immune deficiency syndrome)
• 9 Aids cases were recorded last year -- 8 men, 1 woman
Source: Otago UniversityHIV infections