Plasmodium parasites have recently been documented in the endangered Galapagos penguin (Spheniscus mendiculus). Because avian malaria (caused by Plasmodium spp.) causes high mortality in other avian species after initial exposure, there is great concern for the conservation of the endemic Galapagos penguin. Using a Plasmodium spp. circumsporozoite protein antigen, we have standardized an enzyme-linked immunosorbent assay (ELISA) to test the level of exposure to the parasite in this small population, as indicated by seroprevalence. Sera from adult and juvenile Galapagos penguins collected between 2004 and 2009 on the Galapagos archipelago was tested for the presence of anti - Plasmodium spp. antibodies. Penguins... More
Plasmodium parasites have recently been documented in the endangered Galapagos penguin (Spheniscus mendiculus). Because avian malaria (caused by Plasmodium spp.) causes high mortality in other avian species after initial exposure, there is great concern for the conservation of the endemic Galapagos penguin. Using a Plasmodium spp. circumsporozoite protein antigen, we have standardized an enzyme-linked immunosorbent assay (ELISA) to test the level of exposure to the parasite in this small population, as indicated by seroprevalence. Sera from adult and juvenile Galapagos penguins collected between 2004 and 2009 on the Galapagos archipelago was tested for the presence of anti - Plasmodium spp. antibodies. Penguins were also tested for prevalence of avian malaria parasite DNA, determined by polymerase chain reaction (PCR) screening. Total seroprevalence of malarial antibodies in this sample group was 97.2%, while total prevalence of Plasmodium parasite DNA by PCR screening was 9.2%. This large discrepancy suggests high exposure to the parasite and low Plasmodium - induced mortality, at least under normal environmental conditions. The results of this study also suggest that parasite prevalence may be under-detected through PCR screening and multiple detection methods are necessary to better understand the extent of Plasmodium exposure on the archipelago.
