Fatal hepatic tetratrichomoniasis in a juvenile Waldrapp ibis (Geronticus eremita)

Abstract

Waldrapp ibis (Geronticus eremita) are a critically endangered species, and there are currently more birds in captivity than in the wild. A juvenile, male Waldrapp ibis housed in a mixed-species exhibit was found dead with no premonitory signs. Necropsy revealed extensive necrotizing hepatitis associated with numerous pleomorphic protozoa that were immunohistochemically reactive with antibodies raised against Tritrichomonas foetus, a parasite of cattle. Electron microscopy confirmed the organisms as members of family Trichomonadidae, and sequence analysis of the first ribosomal internal transcribed spacer region (ITS1), 5.8S ribosomal RNA, and ITS2 regions indicated high genetic similarity (96-97%) to members of the Tetratrichomonas gallinarum complex. The animal was born in captivity, and no introductions in this exhibit had occurred since 2009. Other Waldrapp ibis that had contact with the infected male were negative for flagellate infections by fecal examination, thus cross-species transmission is proposed as the source of infection. The host range of the T. gallinarum complex is very large and although the pathogenicity of its members, especially for wild birds, is controversial, these parasites should be considered as a possible cause of acute mortality in Waldrapp ibis. In addition, immunohistochemistry with T. foetus antibodies and molecular diagnostics may be useful tools for preventative veterinary care of endangered bird populations. A greater understanding of the ecology and pathogenesis of this pathogen may also be vital for screening subclinical captive populations and existing wild populations prior to reintroduction efforts.

Screening wild and semi‐free ranging great apes for putative sexually transmitted diseases: Evidence of Trichomonadidae infections

“…The genus Tetratrichomonas, like Trichomonas, belongs to the family Trichomonadidae. Tetratrichomonas are not generally considered to be pathogenic for vertebrate animals; however, rare cases of morbidity or mortality do occur [Laing et al, 2013;Mantini et al, 2009]. To our knowledge, this is the first Figure 2.…”

Do we really need to reconsider coligranulomatosis (Hjärre and Wramby’s disease) in poultry?

“…The studies have been performed in a wide range of bird species, i.e. Coturnix coturnix, Mergus serrator, Lophodytes cucullatus, Somateria mollissima, Alectoris rufa, Pelecanus erythrorhynchos, Geronticus eremita and Mimus polyglottos (Patton & Patton, 1996;Richter et al, 2010;Mostegl et al, 2012;Burns et al, 2013;Laing et al, 2013;Liebhart et al, 2014). Therefore, the absence of parasites in lesions of chickens suffering from the same infection remains surprising.…”

Trichomonads in birds – a review

“…Although the infected chickens appeared healthy, a loss of microvilli and reduction of glycocalyx with complete loss of the polysaccharide matrix was noticed. Two recent reports of tetratrichomonosis in a Waldrapp ibis (Geronticus eremita) (Laing et al 2013) and an American white pelican (Pelecanus erythrorhynchos) (Burns et al 2013), described necrotizing hepatitis or hepatitis/splenitis in the affected birds. Additionally, severe necrotic enteritis of the duodenum and the jejunum of turkeys were reported in that study.…”

“…As none of the molecular methods were used to characterize samples from the diseased bird it cannot be excluded that T. gallinae was responsible for the infection. Two recent reports of tetratrichomonosis in a Waldrapp ibis ( Geronticus eremita ) (Laing et al 2013) and an American white pelican ( Pelecanus erythrorhynchos ) (Burns et al 2013), described necrotizing hepatitis or hepatitis/splenitis in the affected birds. Both reports applied molecular methods for identification of protozoan parasite present in the samples, eliminating the possible confusion with T. gallinae .…”