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| Author(s): |
Ralph Eric Thijl del Val Oñoro Vanstreels
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2014-04-29 |
| Examining board members: |
José Luiz Catão Dias;
Érika Martins Braga;
Fernanda Imperatrice Colabuono;
Ricardo Augusto Dias;
Ricardo José Garcia Pereira
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| Advisor: | José Luiz Catão Dias |
| Abstract | |
Despite no penguin breeding colonies along the Brazilian coast, the country is an important wintering area for the Magellanic penguin (Spheniscus magellanicus), a species native to the south of South America. When Magellanic penguins are found alive ashore on Brazilian beaches, they are taken to rehabilitation centers to receive veterinary care and then are released back into the wild. However, while in rehabilitation, infectious diseases such as avian malaria may become important limiting factors for the recovery of these birds. Avian malaria is a disease caused by protozoa of the genus Plasmodium (Apicomplexa: Haemosporida), which are transmitted to birds through mosquitoes. While these parasites are relatively non-pathogenic for most avian species, some birds such as penguins are exceptionally susceptible, such that Plasmodium poses a significant conservation threat. This study investigates the occurrence of Plasmodium spp. and other blood parasites in Magellanic penguins at rehabilitation centers along the coast of Brazil, and in other species of penguins at the South Shetland Islands, South Atlantic Ocean. In Brazil, a combination of morphological (blood smears, histopathology) and molecular (nested polymerase chain reaction, gene sequencing) diagnostic methods were employed to investigate the presence of haemoparasites in penguins undergoing rehabilitation in six states between 1999 and 2013. A particularly significant avian malaria outbreak was studied in detail at a rehabilitation center in Florianópolis, SC, where the involvement of three distinct Plasmodium spp. in a single epizootic event was demonstrated, with resultant high morbidity and mortality. The occurrence of Plasmodium spp. was documented in Magellanic penguins at rehabilitation centers along most of the Brazilian coast, from southernmost Rio Grande do Sul to Bahia, with an estimated prevalence between 6.6% and 13.5% of captive penguins. These infections were markedly seasonal, with the incidences exclusively restricted to the warmer months of the year (October to April), and involving a broad variety of Plasmodium spp. lineages, some of which had not yet been reported in penguins, such as P. cathemerium, P. nucleophilum and P. tejerai. In contrast, no blood parasites were detected in the penguins sampled at the South Shetland Islands, a finding that is consistent with previous studies. Aside from these epidemiological investigations, an extensive revision and compilation of the scientific literature was conducted for this disease and other penguins haemosporidioses, aiming to establish an integrated understanding of their geographic distribution and epidemiological and conservation implications. On this basis, it is possible to critically examine the state of the art and identify knowledge gaps that can be addressed in future studies. Avian malaria is a significant disease and conservation threat for most penguin species throughout the world, and has particular importance for the rehabilitation and conservation of penguins in South America. (AU) | |
| FAPESP's process: | 09/53956-9 - Study of avian malaria in Magellanic penguins (Spheniscus magellanicus) kept in selected Brazilian coast rehabilitation centers |
| Grantee: | Ralph Eric Thijl Del Val Onoro Vanstreels |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |