Development and application of a dose–response model for Elizabethkingia spp

Elizabethkingia spp. are common environmental pathogens responsible for infections in more vulnerable populations. Although the exposure routes of concern are not well understood, some hospital-associated outbreaks have indicated possible waterborne transmission. In order to facilitate quantitative microbial risk assessment (QMRA) for Elizabethkingia spp., this study fit dose–response models to frog and mice datasets that evaluated intramuscular and intraperitoneal exposure to Elizabethkingia spp. The frog datasets could be pooled, and the exact beta-Poisson model was the best fitting model with optimized parameters α  = 0.52 and β = 86,351. Using the exact beta-Poisson model, the dose of Elizabethkingia miricola resulting in a 50% morbidity response (LD₅₀) was estimated to be approximately 237,000 CFU. The model developed herein was used to estimate the probability of infection for a hospital patient under a modeled exposure scenario involving a contaminated medical device and reported Elizabethkingia spp. concentrations isolated from hospital sinks after an outbreak. The median exposure dose was approximately 3 CFU/insertion event, and the corresponding median risk of infection was 3.4E-05. The median risk estimated in this case study was lower than the 3% attack rate observed in a previous outbreak, however, there are noted gaps pertaining to the possible concentrations of Elizabethkingia spp. in tap water and the most likely exposure routes. This is the first dose–response model developed for Elizabethkingia spp. thus enabling future risk assessments to help determine levels of risk and potential effective risk management strategies.     

Associations between ongoing COVID-19 lockdown and the financial and mental health experiences of Australian families

In 2020, Australia's successful COVID-19 public health restrictions comprised a national “initial lockdown” (March–May) and “ongoing lockdown” (July–November) for metropolitan Victorian residents only. We evaluated associations between ongoing lockdown and family finances and mental health. In the June and September 2020 Royal Children's Hospital National Child Health Polls, caregivers of children in Victoria and New South Wales (NSW) reported the following: job/income loss; material deprivation (inability to pay for essential items); income poverty; mental health (Kessler-6); perceived impact on caregiver/child mental health; and caregiver/child coping. Data from caregivers (N = 1207/902) in June/September were analysed using difference-in-difference modelling (NSW provided the comparator). During Victoria's ongoing lockdown, job/income loss increased by 11% (95%CI: 3%–18%); Kessler-6 poor mental health by 6% (95%CI: −0.3%–12%) and perceived negative mental health impacts by 14% for caregivers (95%CI: 6%–23%) and 12% for children (95%CI: 4%–20%). Female (vs. male) caregivers, metropolitan (vs. regional/rural) families, and families with elementary school-aged children (vs. pre-/high-school) were the most affected. The ongoing lockdown was associated with negative experiences of mental health, employment and income, but not deprivation or poverty, likely because of government income supplements introduced early in the pandemic. Future lockdowns require planned responses to outbreaks and evidence-informed financial and mental health supports.