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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Parasitic Diseases Laboratory » Research » Publications at this Location » Publication #305101

Title: Airsac nematode Monopetalonema alcedinis in the Belted Kingfisher (Megaceryle alcyon)

Author
item BRONSON, ELLEN - Maryland Zoo
item KELLY, KATIE - Johns Hopkins University
item Hoberg, Eric

Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2014
Publication Date: 10/1/2014
Citation: Bronson, E., Kelly, K., Hoberg, E.P. 2014. Airsac nematode Monopetalonema alcedinis in the Belted Kingfisher (Megaceryle alcyon). Journal of Wildlife Diseases. 50:938-941.

Interpretive Summary: Parasites cause disease and mortality in vertebrate hosts, but detailed descriptions of these processes are often elusive as hosts disappear from populations, and are often lost to predators and scavengers in natural environments. Although there have been sporadic and geographically widespread reports of parasites affecting the Belted Kingfisher (Megaceryle alcyon) few published accounts have described details of pathology. We recovered a female, adult kingfisher that had died naturally in a heavily wooded area in Maryland, USA. Examination revealed numerous large adult nematodes (roundworms), Monopetalonema alcedinis, found within the body cavity between organs and completely filling the caudal thoracic and abdominal airsacs. Abundant thick-walled eggs of these parasites were found in the respiratory system, and within the mesentery surrounding multiple internal organs. Monopetalonema alcedinis, is a characteristic member of the superfamily, Diplotriaenoidea, a group of nematode parasites occurring in birds and reptiles. A complex life cycle involves infective larval nematodes that develop in and are ingested with an invertebrate intermediate host such as an insect. Specimens of M. alcedinis have been reported in the Belted Kingfisher, although typically parasite burdens involve few worms, and infections remain asymptomatic. In contrast, we report the second documented case of high burdens of M. alcedinis contributing to host mortality. Our report contributes to a more complete understanding of disease caused by these and related nematodes, and will be useful to avian health specialists, veterinarians, disease ecologists and biologists in revealing the role of parasitic nematodes as mediators of animal health.

Technical Abstract: Sporadic and geographically widespread reports of parasites affecting the Belted Kingfisher (Megaceryle alcyon) have been published but few have described details of pathology. A female, adult kingfisher was found dead in a heavily wooded area of a zoo in Maryland, USA. At necropsy, numerous sexually dimorphic, 4.4 - 40.5 cm long adult Monopetalonema alcedinis worms were found tightly wound within the coelomic cavity between organs, and completely filling the caudal thoracic and abdominal airsacs. Abundant 70-100 µm diameter larvated, thick-walled ova were found in the bronchi and parabronchi, within the mesentery, and in the serosa of multiple coelomic organs. Monopetalonema alcedinis, is a characteristic member of the superfamily Diplotriaenoidea, a group of nematode parasites occurring in birds and reptiles distinct from but often misclassified among Filarioidea due to similar morphology. Infective larvae are ingested with an invertebrate intermediate host and penetrate the intestine, traveling to the lungs and then into the airsacs, where adult females release eggs. The ova are coughed up by the avian host and passed in feces. Specimens of M. alcedinis have been reported in the Belted Kingfisher, although typically parasite burdens involve few worms, and infections remain asymptomatic. In contrast, we report the second documented case of high burdens of M. alcedinis resulting in pathologic findings in which parasitism contributed to host mortality.