The treatment of fungal infections in the Republic of Ireland using outpatient parental antifungal therapy: A retrospective review 2013–2023

• There is an increasing need for infectious disease specialists to become confident in administering antifungal therapy in OPAT settings. • The management of complex fungal infections on OPAT is expanding and is cost effective. • There is a growing need to treat complex fungal infections outside of acute hospital settings. Outpatient parenteral antimicrobial therapy (OPAT) has been recognised as a safe and cost-effective alternative to inpatient treatment. However, there is little published data on the use of antifungal therapy on OPAT for complex fungal infection. We aimed to assess the number of people treated using OPAT for an active fungal infection through the National OPAT programme in the Republic of Ireland between 2013 and 2023. A retrospective analysis of all patients with fungal infections discharged on outpatient antifungal therapy between 1/1/2013 to 1/1/2023 was performed using information available from the national OPAT database. From a national registry of 14,749 patients, 148 (1 %) were treated for fungal infections using OPAT during the study period. The mean age of patients on treatment was 56 years (SD 16.78). Caspofungin was the most frequently prescribed antifungal in 75 patients (51 %) while amphotericin B was prescribed in 41 patients (28 %), followed by anidulafungin (n = 18, 12 %) and fluconazole (n = 14, 9 %). 4 patients (4/148; 2.7 %) received dual antifungal therapy, 3 of those received caspofungin as a second agent and 1 received fluconazole. 30 patients (20 %) received recorded concomitant antimicrobial therapy. The mean numbers of days a patient was receiving treatment for was 23 days, with an interquartile range (IQR) of between 9 and 31 days. Antifungal administration via OPAT for complex fungal infections is infrequent yet increasing in Ireland with the expansion of nationwide OPAT services. Our data demonstrates that it is both an effective method of treatment for patients with these types of infections while also reducing length of hospital stay. As the number of invasive fungal infections diagnosed continue to rise with the advent of emerging mycoses, it is crucial that investment is made in continuing to expand this specialist service. Our study may also demonstrate this model of care could be adopted in other countries where OPAT services for complex fungal infections has not yet been developed. Fungal infections.