The number of people diagnosed with HIV in New Zealand has significantly dropped, according to the AIDS Epidemiology Group of Otago University.
It has been the first time the number has decreased since 2011.
Last year, 197 people were diagnosed, a drop of 46 compared to 2016 when 243 people were diagnosed with HIV.
Dr Sue McAllister said despite the drop being encouraging, it was too early to determine whether the decline would be maintained.
She said changes to HIV management could have contributed to the drop, as diagnosed individuals were now able to begin treatment immediately, and Pre-exposure Prophylaxis was introduced to prevent infection for those who are high risk.
"These new measures, along with use of condoms, regular and early HIV testing and screening and treatment for other sexually transmitted infections all need to be utilised in order to see a continued decline," Dr McAllister said.
Associate Minister of Health Julie Anne Genter said the HIV Pre-Exposure Prophylaxis treatment started to be funded by PHARMAC in March and about 4,000 people could meet the criteria for the treatment each year.
"Hopefully, these new measures, in addition to existing prevention methods, will help to ensure the numbers of people diagnosed with HIV in New Zealand continues to drop in coming years," Ms Genter said.
Executive director Dr Jason Myers from New Zealand AIDS Foundation said the decrease was "wonderful news", but funding was needed to monitor attitudes and behaviours so health workers could determine factors that contribute to the decrease.
"One data point is not a trend. We saw a similar drop from 2010 to 2011, and infection rates consistently rose from then until 2016. We need to see a steady consistent decrease over the next few years before we can confidently say we are on the right track."
He said New Zealand had ongoing surveys that monitored attitudes and behaviours of gay and bisexual men had not been funded since 2014.
"Understanding changes in knowledge and behaviour since the introduction of treatment based prevention tools is critical if we are to ensure the most appropriate targeting of our behaviour change messaging," Dr Myers said.