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.

An outbreak of Bacillus cereus toxin-mediated emetic and diarrhoeal syndromes at a restaurant in Canberra, Australia 2018.

A cluster of gastrointestinal illness was detected following receipt of a complaint of becoming ill after a multi-course dinner at a restaurant in Canberra, Australian Capital Territory (ACT), Australia. The complaint led to an investigation by ACT Health. Food samples retained by the restaurant for microbiological analysis returned an unsatisfactory level of Bacillus cereus in beef (19,000 colony forming units/gram [cfu/g]) and a satisfactory level in arancini (50 cfu/g). These positive samples underwent whole genome sequencing and genes encoding diarrhoeal toxins were detected with no laboratory evidence of the emetic toxin. No stool specimens were collected. A cohort study was undertaken and 80% (33/41) of patrons took part in a structured interview. There was no significant difference in age or sex between those ill and not ill. Due to universal exposure most foods were unable to be statistically analysed and no significant results were found from the food history. The ill cohort diverged into two distinct groups based on incubation period and symptoms suggesting this outbreak involved B. cereus intoxication with both diarrhoeal and potentially emetic toxins. Some hygiene practices during food preparation were noted to be inadequate and heating and cooling procedures were unverified when questioned. A combination of the incubation periods and symptom profile, food laboratory evidence, and genomic sequencing of the B. cereus diarrhoeal gene suggest a probable aetiology of B. cereus intoxication. Public health action included the restaurant rectifying hygiene practices and documenting heating/cooling procedures.