ABSTRACT
Many threats to biodiversity cannot be eliminated; for example, invasive pathogens may be ubiquitous. Chytridiomycosis is a fungal disease that has spread worldwide, driving at least 90 amphibian species to extinction, and severely affecting hundreds of others1-4. Once the disease spreads to a new environment, it is likely to become a permanent part of that ecosystem. To enable coexistence with chytridiomycosis in the field, we devised an intervention that exploits host defences and pathogen vulnerabilities. Here we show that sunlight-heated artificial refugia attract endangered frogs and enable body temperatures high enough to clear infections, and that having recovered in this way, frogs are subsequently resistant to chytridiomycosis even under cool conditions that are optimal for fungal growth. Our results provide a simple, inexpensive and widely applicable strategy to buffer frogs against chytridiomycosis in nature. The refugia are immediately useful for the endangered species we tested and will have broader utility for amphibian species with similar ecologies. Furthermore, our concept could be applied to other wildlife diseases in which differences in host and pathogen physiologies can be exploited. The refugia are made from cheap and readily available materials and therefore could be rapidly adopted by wildlife managers and the public. In summary, habitat protection alone cannot protect species that are affected by invasive diseases, but simple manipulations to microhabitat structure could spell the difference between the extinction and the persistence of endangered amphibians.
Subject(s)
Anura , Chytridiomycota , Disease Resistance , Endangered Species , Mycoses , Refugium , Animals , Anura/immunology , Anura/microbiology , Anura/physiology , Body Temperature/immunology , Body Temperature/physiology , Body Temperature/radiation effects , Chytridiomycota/immunology , Chytridiomycota/pathogenicity , Chytridiomycota/physiology , Disease Resistance/immunology , Disease Resistance/physiology , Disease Resistance/radiation effects , Ecosystem , Mycoses/veterinary , Mycoses/microbiology , Mycoses/immunology , Sunlight , Animals, Wild/immunology , Animals, Wild/microbiology , Animals, Wild/physiology , Introduced SpeciesABSTRACT
OBJECTIVE: Recent randomized trials have demonstrated that endovascular therapy improves outcomes in patients with an acute ischemic stroke from a large vessel occlusion. Subgroup analysis of the Multicenter Randomized CLinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MR CLEAN) study found that patients undergoing general anesthesia (GA) for the procedure did worse than those with nongeneral anesthesia (non-GA). Current guidelines now suggest that we consider non-GA over GA, without large, randomized trials specifically designed to address this issue. We sought to review our experience and outcomes in a program where we routinely use GA in patients undergoing mechanical thrombectomy with similar techniques. METHODS: Patients with anterior circulation strokes who received intravenous tissue plasminogen activator (IV-tPA) and endovascular stroke therapy were included in the analysis. The National Institutes of Health Stroke Scale (NIHSS) on admission and discharge and modified Rankin scale scores at discharge were recorded and compared with the outcome measurements of MR CLEAN. RESULTS: Sixty patients were identified: 39 males and 21 females with a mean age of 62 (range of 29-88). Forty-seven patients were transferred from outside primary stroke centers, while 13 patients presented directly to our institution. Median NIHSS on admission was 15. The median time of symptom onset to endovascular therapy was 265 minutes, with an interquartile range of 81 minutes. Using the thrombolysis in cerebral infarction (TICI) scale, recanalization of TICI 2b-3 was achieved in 76.4% of recorded patients (42/55 recorded). At discharge, mortality was 16.7% (10/60), median NIHSS was 5, and 38.3% (23/60) of patients had a modified Rankin Scale score of 0-2. CONCLUSIONS: General anesthesia does not worsen outcome in patients undergoing mechanical thrombectomy when compared to historical subgroups. Despite a longer time from symptom onset to treatment, our outcomes for patients receiving GA compare favorably to the GA and non-GA groups in MR CLEAN.