Ireland's State of the Environment Report 2024

376 Chapter 14: Environment, Health and Wellbeing Topic Box 14.3  STEC/VTEC infections in Ireland: a persistent threat to public health and wellbeing STEC/VTEC infections are a significant concern for public health in Ireland. Ireland consistently reports the highest rates of STEC/VTEC infections in the EU, with an increasing trend since 2010 (Figure 14.5). Ruminants, mainly cattle, are the primary reservoir of this zoonotic pathogen, which they shed in their faeces. A low infectious dose, with ingestion of just ten STEC/VTEC bacteria from contaminated food or water, is enough to cause symptomatic disease (FSAI, 2010). Children under the age of 5 and the older population are particularly vulnerable to severe illness caused by STEC/VTEC infection and a complication called haemolytic uraemic syndrome, which can be life threatening. More recent data from the Health Protection Surveillance Centre (HPSC) and the European Centre for Disease Prevention and Control (ECDC) highlight that Irish STEC/VTEC notification rates were one of the highest in Europe in 2022. Many factors combine to favour human exposure to this zoonotic pathogen in Ireland: 5 high levels of rainfall, the high density of ruminant animals at pasture and the high proportion of rural dwellers who rely on private sources of untreated water all contribute to our increased risk. Exposure to private well water was the most commonly reported risk factor among STEC/VTEC cases in 2022 (HPSC, 2024). Meteorological events, including persistent and heavy rainfall, have also been shown to concur with STEC/VTEC outbreaks (O’Dwyer et al ., 2016), suggesting that a changing climate is likely to influence the pattern and frequency of outbreaks of this disease in the future. Figure 14.5  Trends in STEC/VTEC in the EU and Ireland, 2007–2022 ˜ Ireland ˜ EU/EEA (without UK) ˜ EU/EEA (with UK until 2019) Notifications per 100,000 population 2022 2021 2020 2016 2017 2018 2019 2015 2014 2013 2012 2011 2010 2009 2008 2007 Year 0 5 10 15 20 25 Source: Adapted from ECDC, Surveillance Atlas of Infectious Diseases 6 Quantifying the relative contribution of potential environmental sources, pathways and temporal dynamics of STEC/VTEC contamination is a priority area, particularly in light of climate change impacts. Improvements in private water supplies are essential if we are to protect human health. This includes ensuring that private wells are properly constructed such that the well head is adequately protected and contamination by surface run-off is prevented and that water is treated by ultraviolet radiation or ultrafiltration. While funding is available through the Department of Housing, Local Government and Heritage (DHLGH) for improvement works for private supplies and group water schemes, during the 2019–2021 funding cycle of the Multi-annual Rural Water Programme, over 60% (€36 million) of the funding available for infrastructural improvements went unused by water suppliers. 5 Zoonotic pathogens are infectious diseases that can be transmitted from animals to humans. 6 https://atlas.ecdc.europa.eu/public/index.aspx – examining notification rate of confirmed cases of STEC/VTEC infection.