Aspergillus Infections in Cetaceans: A Systematic Review of Clinical, Ecological, and Conservation Perspectives

Abstract

Aspergillus spp., particularly A. fumigatus, are increasingly reported as emerging pathogens in cetaceans, yet their clinical and ecological relevance remains poorly characterized. This systematic review synthesizes evidence from 34 studies involving 106 animals, identifying respiratory, neurological, and otic infections as the most frequent presentations with potential interspecies tropism. Invasive disease, frequently fatal, was linked to co-infections-especially with morbillivirus-and environmental stressors such as pollution- and climate-related immune suppression. Despite cetaceans' role as sentinel species, antifungal susceptibility testing and species-level identification were inconsistently performed. Additionally, azole-resistant A. fumigatus strains were isolated from wild porpoises, indicating environmental antifungal exposure and potential public health implications. Aspergillosis remains underdiagnosed in free-ranging populations, particularly in remote or pelagic species. Conservation implications were scarcely addressed, despite evidence suggesting that fungal disease may contribute to morbidity, stranding, and population impact. This review underscores the need for enhanced surveillance, integrative diagnostics, and recognition of fungal pathogens in a One Health framework. The growing intersection of climate change, emerging mycoses, and wildlife conservation positions Aspergillus infections in cetaceans as both a marine mammal health concern and an ecological indicator of broader environmental changes.