Our findings reaffirmed known risk factors, such as young age (0–9 years) and presence of specific stx genes or gene combinations (stx2a; stx1a + stx2a; stx1a + stx2c), and additionally suggest that having outbreak-associated infection, residence within the East region of Ireland, and the combined presence of both ygiW and group_5720 or both pfkA and fieF genes are potentially associated with developing HUS. This evidence concerns the gene STX2 and infection.