Late presentation of HIV infection among adults in New Zealand from 2011 to 2020.

OBJECTIVES: Early diagnosis of HIV is essential for successful treatment and controlling HIV spread in a population. We examined the frequency and characteristics of adults diagnosed late with HIV in New Zealand from 2011-2020. METHODS: Routine surveillance data were analysed. Those previously diagnosed overseas or as part of immigration screening, or with missing CD4 count were excluded. 'Late presentation' was defined as a CD4 count <350 cells/µL or an AIDS-defining event. 'Advanced HIV disease' were those with a CD4 count <200 cells/µL or an AIDS-defining event. Relative risks were calculated using Poisson regression. RESULTS: Of 1145 people, 40.5% presented late; 24.9% had advanced HIV disease. Of the 464 late diagnoses, 65.5% occurred among men-who-have-sex-with-men (MSM), 26.1% among heterosexuals, 8.4% among others. Heterosexual men and women were more likely to present late (55.3%) compared to MSM (35.6%). Amongst MSM, those who were older, of an ethnicity other than European, acquired HIV overseas, tested because symptomatic, or had their last negative test >2 years prior were more likely to present late and have advanced disease. Amongst heterosexuals, older age, tested because symptomatic, and Pacific ethnicity were associated with late presentation, and Maori, Pacific and Asian people were more likely to have advanced disease. CONCLUSIONS: There continues to be a high proportion of people diagnosed late with HIV. Identifying barriers for testing, missed opportunities for screenings and other factors that delay HIV diagnosis could help develop effective strategies to reduce this burden of late presentation - particularly among heterosexual individuals, non-Europeans, and older people.

Population rates of HIV, gonorrhoea and syphilis diagnoses by sexual orientation in New Zealand.

INTRODUCTION: Globally, gay and bisexual men (GBM) are over-represented in HIV, syphilis and gonorrhoea cases. However, surveillance systems rarely provide meaningful measures of inequity, such as population-specific rates, due to a lack of sexual orientation denominators. HIV, gonorrhoea and syphilis are legally notifiable diseases in New Zealand (NZ); we calculate rates by sexual orientation for the first time. METHODS: We analysed 2019 national surveillance data on HIV, syphilis and gonorrhoea notifications disaggregated by sexual orientation. Unique health records identified duplicate notifications and reinfections. Missing data were imputed from known cases. We used the NZ Health Survey 2014/2015 to estimate population sizes by sexual orientation, measured in two ways (current sexual identity, sexual contact in the previous 12 months with men, women or both). We calculated notification rates per 100 000 for each sexual orientation subgroup and rate ratios. RESULTS: In 2019, GBM accounted for 76.3%, 65.7% and 39.4% of HIV, syphilis and gonorrhoea notifications, respectively. Population rates per 100 000 for HIV were 158.3 (gay/bisexual men) and 0.5 (heterosexuals); for syphilis, population rates per 100 000 were 1231.1 (gay/bisexual men), 5.0 (lesbian/bisexual women) and 7.6 (heterosexuals); for gonorrhoea (imputed), population rates per 100 000 were 6843.2 (gay/bisexual men), 225.1 (lesbian/bisexual women) and 120.9 (heterosexuals). The rate ratios for GBM compared with heterosexuals were: 348.3 (HIV); 162.7 (syphilis); and 56.6 (gonorrhoea). Inequities remained in sensitivity analysis (substituting sexual identity with sexual behaviour in the previous 12 months). CONCLUSION: GBM in NZ experience profound inequities in HIV, syphilis and gonorrhoea. Rate ratios by sexual orientation provide useful 'at-a-glance' measures of inequity in disease incidence.