Agamid Adenovirus in Clinically Healthy Bearded Dragons in Italy

Adenoviruses infect various species of squamates, chelonians, and crocodiles, with the most common isolate from bearded dragons being the Agamid adenovirus 1 (AAdV-1). Bearded dragons may remain asymptomatic carriers of AAdV-1 or suffer a diverse range of issues, including neurological symptoms, immunosuppression, reduced growth and death. However, true pathogenicity is unclear and Koch’s postulates have been only fulfilled for an AdV-induced hepatic necrosis in a boa constrictor (Boa constrictor).1 AAdV-1 has been described in Australia, United States, and Europe.2 The aim of the present study was to evaluate the presence of AAdV-1 in captive bearded dragons in Italy. For this purpose, 4 private collections were sampled including a total of 39 bearded dragons of various age and sex. Oral and cloacal swabs were obtained from each bearded dragon and were tested by nested PCR to amplify a partial sequence of the adenoviral DNA polymerase gene.3 Ninety-five percent confidence interval for the prevalence were calculated with the Wilson procedure without a correction for continuity. Out of 39 bearded dragons sampled, 14 resulted positive (prevalence: 36%; 95% CI: 23-52%). Sequencing of the PCR products and comparison with known sequences showed the highest score with AAdV-1. Although results of this study should not be extrapolated in order to obtain the prevalence of AAdV-1 in Italy due to the limited number of samples obtained, these results confirm that AAdV-1 is well established within clinically-healthy captive bearded dragons in private collections in Italy.