224 people were diagnosed with HIV in New Zealand in 2015—a similarly high figure to last year—according to data released today by the AIDS Epidemiology Group based at the Department of Preventive and Social Medicine at the University of Otago.
Men who have sex with men (MSM) were the largest group affected. Of all those diagnosed 153 (68%) were MSM and 42 (19%) were heterosexually infected men and women. There were four people infected thorough injecting drug use, and one child was infected overseas having being been born to a woman with undiagnosed HIV. For most of the remainder the means of infection was not reported.
"Of particular concern is that the number of MSM diagnosed and infected in New Zealand continues at the high rate seen in 2014," says AIDS Epidemiology Group Director Associate Professor Nigel Dickson.
"While the number diagnosed each year will not necessarily reflect the number newly infected, for the past two years there has been a higher number of MSM being diagnosed with evidence of a relatively newly acquired infection, suggesting an increase in recent incidence in this group.
"This does not necessarily mean there has been more risk behaviour, as a rising prevalence resulting from ongoing new infections and longer survival could in itself drive a increase in incidence, even if behaviour is unchanged," Associate Professor Dickson says.
"While regular HIV testing of those at risk is important, people with HIV are most infectious to their sexual partners in the weeks and months after they have been infected, so continued condom use is essential both to prevent acquiring and spreading HIV even among those who last test was negative."
Associate Professor Dickson says the increasing number of infections in recent years suggests that all possible means of decreasing infection risk and spread should be considered.
"Internationally many countries now fund antiretroviral treatment for all people with HIV—whatever their level of immune deficiency—to reduce their infectivity. Some are even considering providing such treatment to high-risk uninfected people, which trials have shown effective in reducing the risk of acquiring HIV."
Of those men and women diagnosed with heterosexually acquired HIV in 2015, about half were infected in New Zealand and half overseas. The number infected in New Zealand has been relatively stable over the past decade.
There was evidence of greater immunodeficiency among those heterosexually infected in this country than the equivalent MSM, suggesting more delay in their diagnoses, which could result in a worse outcome.
Associate Professor Dickson says that while the epidemic is focused on the gay and bisexual community, anyone sick with symptoms that could be due to HIV should be offered an HIV test whatever their sexual behaviour.
He adds: "It is also important that efforts are made to combat the stigma about HIV and the groups most affected, as when this exists testing could be discouraged, and people be less receptive to health promotion messages."
There were a small number of people infected in other ways in 2015. Four people were diagnosed who had been infected through injecting drug use; one child who had been infected overseas was diagnosed having being born to an HIV-infected woman.
Commenting on these, Associate Professor Dickson says New Zealand continues to have only a small number of HIV diagnoses among people who inject drugs thanks to New Zealand's early introduction of the Needle Exchange Programme.
"Nor are we now seeing children contracting HIV from their pregnant mothers in New Zealand as there is a national programme encouraging all pregnant women to be tested, and ensuring treatment to prevent mother to child transmission for those found to be infected."
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Dickson NP, Lee B, Foster T, Saxton P. The first 30 years of HIV in New Zealand: Review of the epidemiology. New Zealand Medical Journal, 2015; 128: 31-47