Avian malaria and penguins in Brazil: epidemiological and pathological investigations of a disease with potential risks to avian conservation

Abstract

Penguins are sentinels of the marine environment and, through their observation and research, one can learn on the nature and intensity of human impacts on the oceans of the Southem Hemisphere. The Magellanic Penguin (Spheniscus magellanicus) inhabits Argentina, Chile and the Malvinas Islands, and visits the Brazilian continental shelf during its winter migration. A significant fraction of these animals eventually strand on Brazilian beaches with poor health conditions and are admitted in Rehabilitation Centers (RCs) distributed along the coast of Brazil. During their permanence in these institutions, one of the most important infectious diseases affecting these animals is avian malaria, a sudden and severe infection that results in high mortality rates. The severity and epizootic behavior of malarial infections in penguins have become an important concern for the international conservation community, raising preoccupation on its potential as a threat to the conservation of these birds if the disease were to spread in an uncertain climatic future. Although there are numerous reports of avian malaria outbreaks in captive penguins, there are no studies clarifying the distribution of that disease in penguins in Brazil, nor is it clear if the infection occurs in the wild or during rehabilitation at the RCs. It is still unclear why the plasmodial infection, typically mild or subclinical in most other avian groups, is so dramatic and severe to penguins; and it is yet unclear how effective are the classic preventive measures that were empirically implemented by zoos and RCs throughout the world. By combining molecular, serological, pathological and hematological diagnostic methods, this project aims to contribute to the understanding of infection, morbidity and mortality patterns of avian malaria in Magellanic penguins undergoing rehabilitation at several RCs along the Brazilian coast or kept in captivity. The results and the development of diagnostic tools will provide information that will help clarify the role of this disease as a potential threatening factor for the conservation of these birds, particularly in relation to possible global climate changes, and discuss preventive measures that may become necessary. (AU)