Animals : an Open Access Journal from MDPI · 6 authors, 3 centres
This summary was generated by AI from a single paper. It has not been reviewed by a clinician and is not clinical advice. Verify against the source before acting on it.
Fungal infections in elasmobranchs (sharks and rays) are rare but often fatal, with Fusarium solani being the most common pathogen. Azole antifungals, particularly voriconazole, show promise for treatment, but pharmacokinetic studies are lacking and current dosing is empirical. This review highlights the urgent need for scientific evidence to establish safe and effective therapeutic protocols for mycoses in cartilaginous fish.
**Background:** Elasmobranchs (sharks and rays) are important in aquarium collections worldwide, but infectious diseases, including fungal infections, are a significant concern. Although fungal infections represent only 0.6% of all diseases in captive elasmobranchs, they carry a high mortality rate. The most common etiological agents are Fusarium spp. (especially Fusarium solani from the Fusarium Solani Species Complex), Exophiala spp., Paecilomyces lilacinus, and Mucor circinelloides. Treatment is largely empirical, with little scientific evidence for antifungal efficacy in this group. Azole antifungals, particularly voriconazole, have shown in vitro activity against Fusarium solani and have been used in a few successful cases.
**Methods:** The authors conducted a narrative review by searching scientific databases (PubMed) and specialized sources (IAAAM archive) for literature on fungal diseases in elasmobranchs and the use of azole antifungal agents. The review summarizes reported cases, treatment approaches, and available pharmacokinetic data.
**Key Results:** The first documented fungal infection in elasmobranchs was in 1986 (Exophiala pisciphila in a smooth dogfish). Since then, cases have been reported in bonnethead sharks (Sphyrna tiburo), scalloped hammerhead sharks (Sphyrna lewini), great hammerhead sharks (Sphyrna mokarran), zebra sharks (Stegostoma fasciatum), and a black stingray (Taeniura melanopsila). Most cases resulted in death despite multimodal therapy. Only three cases reported survival: (1) a bonnethead shark treated with voriconazole 30 mg/kg p.o. s.i.d.; (2) a scalloped hammerhead shark treated with voriconazole 50 mg/kg p.o. b.i.d.; and (3) a roughtail stingray treated with voriconazole 3–4 mg/kg p.o. s.i.d. plus terbinafine and enrofloxacin. Voriconazole plasma concentrations in sharks were low: 1.65 µg/mL after 30 mg/kg p.o. in bonnethead sharks and 1.2 µg/mL after 50 mg/kg p.o. in hammerhead sharks. The minimal inhibitory concentration (MIC) of voriconazole against Fusarium solani is 3–8 µg/mL in vitro, and MIC90 is 2 µg/mL. Other azoles (itraconazole) and terbinafine have been used but with limited success.
**Clinical Implications:** Fungal infections in elasmobranchs are severe and often fatal. Current treatment relies on empirical use of azole antifungals, especially voriconazole, combined with environmental modifications (increased water temperature, salinity, oxygen saturation) and antibiotics for secondary infections. The wide dosage range (4–50 mg/kg p.o.) and low plasma concentrations suggest poor oral bioavailability in elasmobranchs. Parenteral administration (intramuscular or subcutaneous) may be more effective. Pharmacokinetic and pharmacodynamic studies are urgently needed to establish safe and effective dosing regimens. The zoonotic potential of Fusarium solani (FSSC2) also warrants caution for handlers.