Briceno, C. | bioRxiv Science

bioRxiv2025

Detection of zoonotic Cryptosporidium parvum in invasive beavers from southern Tierra del Fuego, Chile

Since their introduction to Tierra del Fuego in 1946, invasive beavers have expanded their population and caused extensive environmental degradation across the subantarctic region. Beaver dams have profoundly impacted peatlands, mature sub-Antarctic forests, and watercourses. Here, we report a pathogen in invasive beavers in Patagonia and discuss their potential role as a reservoir of waterborne zoonotic pathogens. We detected Cryptosporidium through microscopy using the Ziehl-Neelsen staining technique in beaver collected from southern Tierra del Fuego. Out of the 105 beavers examined, three tested positive to optical microscopy, which were then identified molecularly as Cryptosporidium parvum by sequence analysis of the 18S ribosomal DNA (rDNA). Given the potential impacts of Cryptosporidium parvum upon native species, wildlife, and human health, this finding highlights the potential risks associated with the ongoing expansion of beavers into other areas of the sub-Antarctic region. A potential role of invasive beavers as reservoirs of zoonotic Cryptosporidium spp. in Patagonia emphasizes the unknown consequences of human-introduced exotic species on pristine ecosystems.

bioengineering↗

bioRxiv2020

Sarcoptic mange; an emerging threat to Chilean wild mammals?

Sarcoptic mange has been anecdotally reported in Chilean wildlife during the last decade. Although this disease can have devastating outcomes for biodiversity, there is no comprehensive assessment of this potential threat in Chile. Because the current capacity to monitor sarcoptic mange and other wildlife diseases is limited in this country, we used abnormal alopecia to search for suspect cases across several sources of information to identify, to the extent available data allow, the location and temporal trends of wild mammals with this characteristic across Chile. We surveyed park rangers, examined rehabilitation center databases, and collated citizen and media reports. The information gathered suggests that observations of alopecic wild mammals, mainly foxes (Lycalopex sp.), their presence in the country, and the number of species fulfilling our case definition have increased over the last 15 years. Moreover, abnormally alopecic mammals are currently located broadly in Chile. We also confirmed the utility of abnormal alopecia to define a suspect sarcoptic mange case in the most commonly affected group, Lycalopex foxes. Our findings are highly concerning from a conservation perspective. We thus emphasize the need for an urgent surveillance and management plan for sarcoptic mange and other diseases that may be threatening Chilean biodiversity.

ecology↗