Yersiniosis outbreaks in Gold Coast residential aged care facilities linked to nutritionally-supplemented milkshakes, January-April 2023.

Abstract: In January 2023, an outbreak of Yersinia enterocolitica in residential aged care facilities (RACF) was identified by the Gold Coast Public Health Unit and confirmed using whole genome sequencing. During the outbreak period there were 11 confirmed and 14 probable cases of Y. enterocolitica notified in RACF and 30 suspected cases with compatible illness. Eleven cases (20%) were confirmed as Biotype 1A non-typable (BT1A NT) sequence type (ST) 278 within 4-15 single nucleotide polymorphisms (SNP) of each other. Combined epidemiological, trace-back and laboratory investigations identified nutritional milkshakes, stored at ideal growing conditions for Yersinia and given to vulnerable RACF residents, as the likely outbreak vehicle. This highlights that Y. enterocolitica Biotype 1A can be pathogenic in humans and transmission via atypical sources should be considered in outbreak investigations. This report outlines the response and challenges associated with investigating outbreaks in aged care.

Wave of COVID-19 outbreaks in Gold Coast residential aged care facilities after easing travel restrictions into Queensland.

Objective: This paper describes outbreaks of coronavirus disease 2019 (COVID-19) in Gold Coast residential aged care facilities (RACFs), in the two months following the easing of travel restrictions at Queensland's domestic border on 13 December 2021. Methods: This audit reviewed all RACF COVID-19 outbreaks notified to the Gold Coast Public Health Unit between 13 December 2021 and 12 February 2022. An outbreak was defined by the Communicable Diseases Network Australia guidelines current at the time. Results: There were 60 COVID-19 outbreaks across 57 RACFs during this period. In 44 outbreaks (73.3%), a staff member was identified as the primary or co-primary case. Transmission amongst residents occurred in 48 outbreaks (80.0%). The attack rates in staff and residents were 17.0% (n = 1,060) and 11.7% (n = 645) respectively. A higher number of males were hospitalised (n = 39: 57.4%) or died (n = 28: 66.7%) than were females (n = 29: 42.6%; n = 14: 33.3% respectively). Most resident cases (n = 565: 87.6%) had received two or more doses of a COVID-19 vaccine. In resident cases who were under-vaccinated (n = 76), twenty (26.3%) required hospitalisation and nine (11.8%) died. In resident cases who received two doses of vaccine (n = 484), forty-three (8.9%) were hospitalised and 27 (5.8%) died. In resident cases who had received three doses (n = 80), four (5.0%) were hospitalised and five (6.3%) died. Conclusions: COVID-19 caused significant morbidity and mortality in Gold Coast RACFs following the easing of border restrictions. Higher rates of hospitalisation and death occurred in males than in females, and in under-vaccinated resident cases than in those vaccinated with at least two doses of a COVID-19 vaccine. Implications for public health: These data support the need for up-to-date COVID-19 vaccination of residents in RACFs, continued surveillance and timely and appropriate implementation of public health guidelines to manage COVID-19 outbreaks in RACFs.

An outbreak of Q fever associated with parturient cat exposure at an animal refuge and veterinary clinic in southeast Queensland.

OBJECTIVE: To determine the source of a Q fever outbreak in humans at an animal refuge and veterinary clinic in southeast Queensland from October to December 2016. METHODS: Case interviews and a retrospective cohort study of animal refuge and veterinary clinic staff using a self-administered questionnaire related to clinical history of Q fever, Q fever vaccination status and workplace activities during the exposure period. RESULTS: Seven cases (six confirmed, one probable) were identified. Forty-three questionnaires were completed (92% response rate). Workplace activities associated with the greatest risk of illness were the disposal of deceased cats or dogs (RR, 14.0; 95%CI, 1.9-104.1) and participating in euthanasia of cats or dogs (RR, 4.6; 95%CI, 1.3-16.9). Five feline birthing events occurred at the animal refuge from 25 September to 19 October 2016, each with subsequent euthanasia of the queen cat and litter. All cases had likely exposure to a specific queen cat and her litter that were euthanised the same day as the birthing event. CONCLUSIONS: A parturient cat was the most likely source of the outbreak. Implications for public health: Occupational groups and others with regular exposure to feline or canine parturient products should receive Q fever vaccine.