Shigellosis and antimicrobial resistance in Shigella in Australia from 2017-2024

Abstract

Background and Aim Global emergence of antimicrobial-resistant Shigella strains poses a major challenge for the control of shigellosis. This study aimed to describe national trends and sociodemographic characteristics of shigellosis cases in Australia between 2017–2024 to inform surveillance and interpretation of emerging antimicrobial resistance (AMR) patterns. Methods and Analysis Descriptive analyses of National Notifiable Diseases Surveillance System (NNDSS) data examined temporal trends; age and sex distribution; geographic patterns by remoteness and Index of Relative Socio-economic Advantage and Disadvantage (IRSAD); acquisition location (overseas, Australia, unknown); and laboratory characteristics (organism, subtype, testing method). Analyses were conducted using R version 4.5.1. Outcomes 16,761 confirmed and probable cases of shigellosis were notified to the NNDSS between 1 January 2017–31 December 2024. Crude notification rates peaked at 12.4 cases per 100,000 in 2019, declined to a low of 1.8 per 100,000 in 2021 during the COVID-19 pandemic, and increased from 2022 onwards, returning to high levels by 2023–2024. 54.8% of notifications (9,191/16,761) were male. Median age was 32 years (IQR 13–48). Adults aged 20–49 years represented the largest proportion (7,964/16,761, 47.5%), followed by children aged 0–4 years (2,578/16,761, 15.4%). Of all notifications, 5,818 (34.7%) were overseas-acquired; 4,882 (29.1%) Australian acquired; and 6,061 (32.5%) unknown. Notification rates were highest in IRSAD decile 1 (178 per 100,000 population), followed by deciles 9 (116.6 per 100,000) and 10 (100.9 per 100,000). Conclusion and Future Actions National notifications indicate substantial and evolving burden of shigellosis in Australia, including a post-pandemic resurgence in transmission. Disproportionate impact among young children and key adult populations identifies potential priority groups for prevention. Variation by remoteness area and IRSAD decile highlights differences in notification distribution. Planned analyses integrating Antimicrobial Use and Resistance in Australia (AURA) surveillance program Shigella data will strengthen the epidemiological findings by examining AMR patterns to inform surveillance priorities and support timely, targeted public health response. Show more