Sarcoptic Mange Outbreak Decimates South American Camelid Populations in San Guillermo National Park, Argentina

In San Guillermo National Park, Argentina, a sarcoptic mange outbreak from 2017 to 2019 severely impacted vicuña and guanaco populations, with a 68% and 77% decrease in their densities, respectively, and no individuals recorded by April 2019, indicating near-local extinction. Clinical signs of mange were observed in 24% of live vicuña and 33% of live guanaco, and in 94% of vicuña and 85% of guanaco carcasses. Histological examination confirmed sarcoptic mange as the cause, and genetic analysis suggested a single source of the outbreak. The introduction of mange-infected llama through a governmental program in 2009 is hypothesized to have triggered the outbreak, underscoring the potential for devastating effects on native wildlife from accidental disease introduction.