Summary

The Enteric Reference Laboratory (ERL) typed 153 Shigella isolates in 2024, an increase of 41 from 2023. This included three Shigella boydii and no Shigella dysenteriae compared to four boydii and two dysenteriae in 2023. Although all the S. boydii were associated with travel to India in 2023, 2024 cases had travel to India, Peru and Bangladesh. Additionally, there were 69 S. flexneri and 81 S. sonnei typed, an increase of 24 (53.3%) and 20 (32.8%), respectively. These were predominantly associated with foreign travel (98/153, 64.1%) from a wide range of overseas destinations based on data from Episurv, with 36.9% of isolates associated with travel to the Pacific Islands. S. boydii typed isolates comprised two sequence types, ST243 and ST145, with one of the ST145 isolates flagged as potentially multi-drug resistant (MDR) based on the presence of antimicrobial resistance genes and point mutations (drug resistance predictions are not verified by phenotypic testing in all cases). S. flexneri isolates were much more diverse with ST1024 (two total), ST1025 (six total), ST145 (nine total and one MDR flag), ST1513 (two total and two MDR flag), ST245 (48 total and seven MDR flag), and ST628 (2 total). S. sonnei was reported as a single sequence type, ST152, with one isolate flagged as MDR and 25 flagged as extensively drug resistant (XDR). This is an increase of 17 XDR isolates from the previous year but a decrease in the number of MDR isolates from three to one. In total, foreign travel was associated with 19 of 37 (51.4%) isolates flagged as drug resistant, indicating the possibility of local transmission of resistant Shigella in New Zealand.