Haemoproteosis lethality in a woodpecker, with molecular and morphological characterization of Haemoproteus velans (Haemosporida, Haemoproteidae)

Abstract

A juvenile White-headed woodpecker ( Dryobates albolarvatus ) fitted with a radio tag was located dead at approximately 22-days post-fledging in Yakima county in central Washington in July 2015. Postmortem examination revealed an enlarged liver and spleen plus evidence of iron sequestration. Microscopic examination observed young gametocytes within the cytoplasm of erythrocytes, and exo-erythrocytic meronts within the cytoplasm of capillary endothelial cells, hepatocytes, and myocytes, and free in the tissues. These attributes implicated a haemosporidian infection that likely resulted in mortality. Subsequent sampling results of local woodpecker species in the same area during the breeding season in June–July 2016 and May–July 2017 showed other individuals infected with Haemoproteus parasites. Nested Polymerase Chain Reaction (PCR), sequencing, and microscopic analyses for avian haemosporidians revealed infections with Haemoproteus velans (Haemosporida, Haemoproteidae). This parasite was characterized molecularly and morphologically. This is the first report of a haemosporidian infection in a White-headed woodpecker anywhere in its range, and the first reported suspected mortality from haemoproteosis for a woodpecker (Piciformes, Picidae). The use of radio-tagged birds is an asset in wildlife haemosporidian studies because the effect of the pathogen can be monitored in real time. Additionally, this methodology provides opportunities to collect fresh material for microscopic and histological examination from wild birds that have died from natural causes.

The life-cycle of the avian haemosporidian parasite Haemoproteus majoris, with emphasis on the exoerythrocytic and sporogonic development

“…Early studies usually considered Haemoproteus parasites as relatively benign in the vertebrate hosts [16]. However, the application of molecular diagnostic methods has challenged this opinion due to the discovery of numerous well-documented cases of severe haemoproteosis in non-adapted avian hosts [17–23]. Severe pathologies and even mortality have been reported, particularly when Haemoproteus infection was established in non-adapted (“wrong”) avian hosts.…”

Complete sporogony of the blood parasite Haemoproteus nucleocondensus in common biting midges: why is its transmission interrupted in Europe?

“…These studies are useful for better understanding the causes of parasite spread and the emergence of new diseases. Avian haemosporidian parasites are widespread, and they cause severe disease or even mortality in non-adapted birds (Garnham, 1966;Donovan et al, 2008;Cannell et al, 2013;Tostes et al, 2015;Ilgūnas et al, 2016;Jia et al, 2018;Kelly et al, 2018;Groff et al, 2019). In the past 30 years, the number of studies on the prevalence and diversity of haemosporidian parasites has increased, but the vectors transmitting these parasites have been insufficiently investigated (Valkiūnas, 2005;Santiago-Alarcon et al, 2012;Žiegytė et al, 2017;Bukauskaitė et al, 2019).…”

“…European birds gain many Haemoproteus parasites at the breeding sites (Valkiūnas, 1993(Valkiūnas, , 2005, but precise information on the epizootiology of these infections remains insufficiently investigated. Numerous recent studies indicate that Haemoproteus parasites might be dangerous and even deadly, especially for non-adapted birds (Atkinson et al, 2008;Donovan et al, 2008;Cannell et al, 2013;Jia et al, 2018;Kelly et al, 2018;Ortiz-Catedral et al, 2019;Groff et al, 2019). The possibility that H. nucleocondensus infection could be virulent and even kill non-adapted juvenile birds cannot be ruled out due to the lack of experimental research or other observations on the virulence of this infection.…”

Hemosporídeos parasitos (Haemosporida: Apicomplexa) em aves de rapina neotropicais: diversidade, abordagem integrativa e conservação

“…Os complexos ciclos de vida, a epidemiologia, a baixa parasitemia e a dificuldade da coleta de dados em aves silvestres estão entre os fatores para o desconhecimento dos efeitos deletérios desses parasitos sobre as aves. Por muitos anos acreditou-se que os hemosporídeos eram relativamente inofensivos para as aves silvestres, porém, a cada ano novos estudos têm demonstrado que a patogenicidade depende da espécie infectante, da capacidade imunológica do hospedeiro, entre outros fatores, podendo levar os animais à morte (OLIAS et al, 2011;CANNELL et al, 2013;SANTIAGO-ALARCON et al, 2013;GROFF et al, 2019).…”

“…No entanto, estudos recentes têm demonstrado alta letalidade, muitas vezes associada à espécie do parasito. Além disso, quando essa letalidade não ocorre, os hemosporídeos podem causar declínio na população aviária, devido à diminuição da capacidade reprodutiva, alteração em padrões comportamentais, efeitos na adaptabilidade dos hospedeiros ao ambiente, diminuição da habilidade de caça -tão essencial para grande parte dos rapinantes -entre outros efeitos adversos (ALTIZER et al, 2001;OLIAS et al, 2011;SANTIAGO-ALARCON et al, 2013;GROFF et al, 2019).…”