First report of avian malaria in a Manx shearwater (Puffinus puffinus).

This study reports the case of a Manx shearwater (Puffinus puffinus) that died from avian malaria while under care at a rehabilitation center in Espírito Santo, Brazil. The bird was rescued on October 2018, and remained under care until it died suddenly on January 2019. A blood smear produced 8 days before death was negative for parasites, whereas a blood smear produced post-mortem revealed a high parasitemia by a parasite resembling Plasmodium cathemerium. The sequence of a 412 bp segment of the cyt-b gene was identical to that of lineage PADOM09, and phylogenetic analysis corroborated that this parasite was closely-related to known lineages of P. cathemerium. The acuteness and severity of the infection documented in this case suggest that seabirds of the order Procellariiformes might be highly susceptible to Plasmodium infections, raising the concern that avian malaria may present a significant threat to their conservation.

Epidemiology, hematology, and unusual morphological characteristics of Plasmodium during an avian malaria outbreak in penguins in Brazil.

Avian malaria is a mosquito-borne disease caused by Plasmodium spp. protozoa, and penguins are considered particularly susceptible to this disease, developing rapid outbreaks with potentially high mortality. We report on an outbreak of avian malaria in Magellanic penguins (Spheniscus magellanicus) at a rehabilitation center in Espírito Santo, southeast Brazil. In August and September 2015, a total of 89 Magellanic penguins (87 juveniles and 2 adults) received care at Institute of Research and Rehabilitation of Marine Animals. Over a period of 2 weeks, Plasmodium infections were identified in eight individuals (9.0%), four of which died (mortality = 4.5%, lethality = 50%). Blood smears and sequencing of the mitochondrial cytochrome b gene revealed the presence of Plasmodium lutzi SPMAG06, Plasmodium elongatum GRW06, Plasmodium sp. PHPAT01, Plasmodium sp. SPMAG10, and Plasmodium cathemerium (sequencing not successful). Two unusual morphological features were observed in individuals infected with lineage SPMAG06: (a) lack of clumping of pigment granules and (b) presence of circulating exoerythrocytic meronts. Hematological results (packed cell volume, plasma total solids, complete blood cell counts) of positive individuals showed differences from those of negative individuals depending on the lineages, but there was no overarching pattern consistently observed for all Plasmodium spp. The epidemiology of the outbreak and the phylogeography of the parasite lineages detected in this study support the notion that malarial infections in penguins undergoing rehabilitation in Brazil are the result of the spillover inoculation by plasmodia that circulate in the local avifauna, especially Passeriformes.