Molecularly confirmed acute, fatal Sarcocystis falcatula infection in the rainbow lorikeets (Trichoglossus moluccanus) at the Philadelphia Zoo, USA

Authors: VERMA, SHIV - Non ARS Employee; TRUPKIEWICZ, JOHN - Philadelphia Zoo; GEOROFF, TIM - Philadelphia Zoo; Dubey, Jitender

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2018
Publication Date: 8/29/2018
Citation: Verma, S.K., Trupkiewicz, J.G., Georoff, T., Dubey, J.P. 2018. Molecularly confirmed acute, fatal Sarcocystis falcatula infection in the rainbow lorikeets (Trichoglossus moluccanus) at the Philadelphia Zoo, USA. Veterinary Parasitology. https://doi.org/10.1645/18-78.
DOI: https://doi.org/10.1645/18-78

Interpretive Summary: Toxoplasma and Sarcocystis are related single celled parasites of livestock and humans. While Toxoplasma has long been recognized to cause neurologic disease in many warm-blooded hosts, several species of Sarcocystis also cause a variety of disorders in livestock, pets, and wild animals and some of them are zoonotic. Certain avian species, especially in captivity, can die suddenly with acute sarcocystosis and diagnosis is difficult. In the present investigation, authors report molecular diagnosis of acute, fatal sarcocystosis in lorikeets exihibited at the Philadelphia zoo. The results will be of interest to biologists, zoo veterinarians, and parasitologists, and help diagnosis of sarcocystosis.

Technical Abstract: The protozoan parasite Sarcocystis falcatula is an important cause of clinical disease in several avian intermediate hosts. The host range of S. falcatula is wide and numerous outbreaks of acute sarcocystosis have been reported in passerine and psittacine birds in captivity in the Americas. Previous diagnosis was performed by serologic methods, light and/or electron microscopic examinations with limited molecular confirmation. Here, we report molecular diagnosis of histologically confirmed acute, fatal S. falcatula infections in rainbow lorikeets (Trichoglossus moluccanus) at the Philadelphia Zoo. Pulmonary sarcocystosis was suspected antemortem in three 3-5 years old lorikeets; these birds died despite anti-protozoal therapy. The predominant lesion was pneumonia associated with S. falcatula-like schizonts in pulmonary vascular endothelium. The multilocus PCR-DNA sequencing (18S rDNA, 28S rDNA, ITS-1, and cox1) of frozen lung tissue confirmed S. falcatula infections in all three birds. Our results and previous studies suggest that acute pulmonary form of sarcocystosis is a major contributor of death to old world psittacine birds.