Clinical Presentation and Outcomes Following Infection With spp, spp, , and spp Water-Associated Organisms in Tropical Australia, 2015-2022.

Background: Water-associated bacterial infections cause a wide spectrum of disease. Although many of these infections are typically due to human host commensal or spp, water exposure can result in infections with environmental gram negatives such as spp, spp, , and spp (collectively VACS).

Methods: We performed a retrospective analysis of the epidemiology, clinical presentation, and outcomes of deep and superficial infections associated with VACS organisms in our health service between 1 January 2015 and 31 December 2023.

Results: We identified 317 patient episodes of infection with VACS organisms over this period. Of these, spp (63%) was the most common, followed by spp (19%), spp (13%), and (5%). The majority were isolated from males (74.4%) and involved the lower limb (67.5%). Mild infections were more common than severe presentations, with only 15 (4.7%) admissions to the intensive care unit and 8 (2.5%) deaths. Colonization occurred in 6.9% of patients, in contrast to the perceived severity of some of these bacteria. Copathogens were common and included (48%) and enteric bacteria (57%). The majority of patients (60%) had no documented water exposure. Initial empiric antimicrobial therapy presumptively covered the susceptibilities of the isolated organisms in 47.3% of patients; however, a lack of VACS-covering empirical therapy was not associated with readmission.

Conclusions: The isolation of a VACS organism in our setting was often not associated with documented water exposure, which has implications for empiric antimicrobial therapy. Severe disease and death were uncommon.