Infectious diseases in Italian amphibians and reptiles: state of the art and systematic review

Infectious diseases are an important conservation concern for amphibians and reptiles, but evidence from free-ranging Italian herpetofauna has never been synthesised at national scale, despite the country's highly diverse herpetofauna, which includes numerous endemic and threatened taxa. We systematically reviewed primary studies on infectious agents in wild amphibians and non-marine reptiles in Italy, distinguishing host-level infectious disease from pathogen occurrence without documented disease and from targeted investigations with no evidence of detection. Searches of PubMed, Scopus and Web of Science, supplemented by Google Scholar and reference-list screening, identified 49 eligible studies published between August 2003 and July 2026: 39 on amphibians and 10 on reptiles, yielding 434 epidemiological records across 52 analytical host taxa and 16 pathogen entities. Of 84 investigated host-pathogen combinations, 21 included disease evidence, 14 positive occurrence only and 49 exclusively negative investigations. After reconciliation of overlapping records, 57 disease-evidence strata were identified: 23 confirmed, 21 presumptive and 13 suspected. Research effort was strongly concentrated: Batrachochytrium dendrobatidis accounted for 203 records from 25 studies and Ophidiomyces ophidiicola for 151 records from five studies, together representing 81.6% of all extracted records. Pathogens were detected in 16 of the 20 Italian regions, whereas disease evidence was available for eight. Of the 15 pathogen entities retained in the European eligibility framework, nine had been investigated in Italy; six had disease evidence, three were represented only by negative investigations, and six had no eligible Italian record. Overall methodological support was rated High for 44 of 49 studies. Infectious diseases are documented across multiple Italian amphibian and reptile taxa, but marked differences in research effort, host coverage and geographic representation prevent reliable estimates of disease frequency or its impact on free-ranging populations at national scale. Further work should prioritise epidemiologically relevant gaps and combine pathogen detection with clinical, pathological and longitudinal population-level evidence.