Again suggesting that Bd DNA similarly might not have been present in each replicate

Because a single replicate was positive from three different plates, including the final qPCR using purified DNA, these data do suggest MGHA54 was positive for Bd. Although it is difficult to discern the truth about MGSS30 and MGHA54, because separate plates yielded positive replicates and contamination was unlikely, I report these samples as Bd-positive. Regardless, all nine replicates of MGHB42 were positive for Bd, undeniably confirming its presence in material from Madagascar. The status of Bd in wild amphibian populations in Madagascar remains uncertain and calls for urgent targeted field surveys in regions where these Bd-positive animals were likely collected. The human-assisted movement of traded animals introduces an opportunity for Bd cross-contamination between species and collection origins prior to exportation if animals are housed in shared enclosures where direct or indirect contact is allowed. Accordingly, transmission of Bd between Malagasy species from different collection localities may potentially exaggerate the number of affected species in wild populations and suggested distributional range of infection.. Furthermore, identifying the source of Bd detected in traded animals becomes especially challenging when animals from multiple countries are also present in the trade sector. Fortunately, this is not the case in Madagascar; commercial amphibian importation does not occur in the country and only those of national origin are traded. The absence of foreign-sourced amphibian species suggests my detection of Bd is not simply an artifact of re-exportation through the amphibian trade, but instead a reflection of Bd presence in the wild in Madagascar. Still, other non-amphibian wildlife trade activities may unknowingly introduce foreign infectious material to Madagascar and expose wild-collected frogs prior to exportation if housed at a shared facility. Albeit unlikely the result of such cross contamination, I employed a conservative approach by interpreting these data as confirmation of Bd presence in Madagascar within the amphibian trade, but not yet irrefutable evidence for Bd presence in wild amphibian populations, despite the strong suggestion. A second, more specific tier of surveillance via targeted field sampling applying this new information, is now imperative to determine the current extent of Bd in Madagascar outside the trade sector. A Isoacteoside predictive model of Bd distribution shows that the highest climatic suitability for Bd overlaps particularly closely with the distributional range of H. betsileo, from which MGHB42 was collected. Interestingly, the distributions of H. albuguttatus and S. Isochlorogenic-acid-C spinosa fall on the periphery of this climatic range and may have been collected from areas with moderate to low Bd suitability, potentially explaining their exceptionally low Bd zoospore loads compared to that detected in the specimen of H. betsileo. Accordingly, surveys to trace back the source of the Bd detected herein should commence immediately within the distributional ranges of H. betsileo, H. alboguttatus, and S. spinosa, target the larvae and subadults expected to exhibit increased susceptibility to infection.