Epidemiology is the study of the distribution and determinants of disease.  The AIDS Epidemiology Group at the University of Otago is responsible for the collection of information about new HIV cases in New Zealand, and publishes regular updates in the AIDS – New Zealand newsletter.  

The NZAF Research Unit works closely with the AIDS Epidemiology Group to further analyse and disseminate information about trends in HIV diagnoses and HIV infection, with a particular focus on men who have sex with men (MSM).

The Research Unit produces an annual briefing paper on the latest diagnosis data among MSM.

Figure 1 below charts the annual number of new HIV diagnoses according to the main modes of HIV transmission. Figure 2 charts the place of infection for diagnoses attributed to sex between men, and Figure 3 charts the place of infection for diagnoses attributed to heterosexual sex.