Studies of trichomonad protozoa in free ranging songbirds: Prevalence of Trichomonas gallinae in house finches (Carpodacus mexicanus) and corvids and a novel trichomonad in mockingbirds (Mimus polyglottos)

First reported case of Trichomonas gallinae infection in red-breasted toucan (Ramphastos dicolorus)

This study reports the infection and diagnosis of the protozoan morphologic complex Trichomonas gallinae in a baby red-breasted toucan (Ramphastos dicolorus). Nodular lesions on the soft palate and edema in the oral cavity were observed macroscopically. Microscopically, a granuloma with multiple layers of necrosis interspersed with inflammatory polymorphonuclear infiltrates was observed. Parasitism was confirmed by parasitological diagnosis, isolation of the flagellates in culture medium, and Polymerase Chain Reaction (PCR) using 5.8S ribosomal RNA (rRNA). Flanking internal transcribed spacer (ITS) gene regions were amplified by polymerase chain reaction, and the sequences were analyzed phylogenetically using MEGA 11 software. Phylogenetic analysis based on ITS1/5.8S rRNA/ITS2 sequences demonstrated high nucleotide identity with two Trichomonas sequences available in GenBank, which were more closely related to T. vaginalis (99%) than to T. gallinae (98%). In addition to being potential transmitters of this protozoan, rigorous monitoring of infectious and parasitic diseases in wild bird populations is essential for their preservation. The forms of transmission of Trichomonas sp. favor the occurrence of the disease in many non-Columbiformes species, which is essential for the monitoring of this disease in wild birds.

Trichomonas gallinae Kills Host Cells Using Trogocytosis

Trichomonas gallinae (T. gallinae) is an infectious parasite that is prevalent worldwide in poultry and can cause death in both poultry and wild birds. Although studies have shown that T. gallinae damages host cells through direct contact, the mechanism is still unclear. In this study, we found that T. gallinae can kill host cells by ingesting fragments of the host cells, that is, by trogocytosis. Moreover, we found that the PI3K inhibitor wortmannin and the cysteine protease inhibitor E-64D prevented T. gallinae from destroying host cells. To the best of our knowledge, our study has demonstrated for the first time that T. gallinae uses trogocytosis to kill host cells. Understanding this mechanism is crucial for the prevention and control of avian trichomoniasis and will contribute to the development of vaccines and drugs for the prevention and control of avian trichomoniasis.

Profile likelihood confidence interval for the prevalence assessed by an imperfect diagnostic test

We present a new confidence interval for the prevalence of a disease for a situation when sensitivity and specificity of the diagnostic test are estimated from validation samples independent of the study sample. The new interval is based on profile likelihood and incorporates an adjustment improving the coverage probability. Its coverage probability and expected length were assessed by simulation and compared to two other methods for this problem, namely those by Lang and Reiczigel (2014) and Flor et al. (2020). Expected length of the new interval is less than that of the Lang and Reiczigel interval while its coverage is about the same. Comparison to the Flor interval resulted in similar expected length but higher coverage probabilities for the new interval. All in all, the new interval proved to be better than both its competitors.

Tetratrichomoniasis in the Geese Flock—Case Report

Infections caused by tetratrichomonas are commonly observed in geese. Most cases are subclinical, and the clinical form of the disease manifests itself with a greater mortality and the presence of caseous content in ceca. We describe the case of tetratrichomoniasis in a geese flock caused by Tetratrichomonas gallinarum, with the genetic analysis of the isolate being based on the fragments of 18SrRNA and ITS1-5.8rRNA-ITS2.

Prevalence and diversity of Trichomonas gallinae in meat pigeons (Columba livia) in Guangdong Province, People's Republic of China

Pigeon farming for meat has developed into an important economic industry in most countries, especially in China. Trichomoniasis, caused by the protozoan parasite Trichomonas gallinae, is a worldwide disease in pigeons. However, studies of the prevalence and distribution of T. gallinae lineages in domestic pigeons in southern China are limited. In this study, a total of 636 pigeon throat swabs samples from four regions in Guangdong Province were screened for T. gallinae by in vitro culture assays and microscopy. The results revealed an overall prevalence of T. gallinae infection in southern China of 26.6% (169/636). There were significant differences in the infection rate of T. gallinae between the four regions (χ² = 117.948, df = 4, P = 0.000), with up to 44.6% in the Pearl River Delta region. The infection rate of young pigeons was as high as 70.8%. The rDNA sequences (18S rRNA/ITS1-5.8S rRNA-ITS2) of 153 positive samples were amplified and sequenced. Results identified 58.2% (89/153) overall as ITS-A (18S-VI) (also known as ITS-OBT-Tg-1) and 41.8% (64/153) as ITS-B (18S-IV) (also known as ITS-OBT-Tg-2). Thus, ITS-A (18S-VI) was the dominant T. gallinae genotype in southern China, especially in young pigeon (97.0%, 32/33). In conclusion, a high prevalence of T. gallinae infection in domestic pigeons was identified in southern China, particularly in the Pearl River Delta region. The ITS-A (18S-VI) was the dominant genotype highly pathogenic, which may weaken the immune system of pigeons, and cause a negative impact on the development of the pigeon industry in China.

A new duplex real-time PCR for simultaneous detection and differentiation of Tetratrichomonas gallinarum and Trichomonas gallinae

Tetratrichomonas gallinarum and Trichomonas gallinae are pathogenic avian parasites that infect a wide range of bird species. The pathologic potential of T. gallinarum is controversial, whereas T. gallinae causes disease in many avian species. Infections are often asymptomatic in doves and pigeons; thus, columbids are presumed to represent the natural hosts for trichomonads. The detection of T. gallinarum and T. gallinae is based on direct microscopic observation or a conventional PCR assay. Microscopy is not very sensitive, and identification of the trichomonads at the genus or species level is not possible. Conventional PCR assays have been developed primarily for phylogenetic studies, which detect a wide range of Trichomonas spp. but do not allow their differentiation. We developed a duplex real-time PCR (rtPCR) assay for the simultaneous detection and differentiation of T. gallinarum and T. gallinae. We found that the rtPCR assay detected 10² plasmid DNA copies of T. gallinarum and as few as 10¹ plasmid DNA copies of T. gallinae.

Trichomonosis in Austrian Songbirds—Geographic Distribution, Pathological Lesions and Genetic Characterization over Nine Years

In the early summer of 2012, sudden mass mortality among songbirds, particularly in greenfinches (Chloris chloris, syn: Carduelis chloris) was observed in Austria, which was caused by the protozoan parasite Trichomonas gallinae. This pathogen induced fibrinonecrotic ingluvitis and/or esophagitis, leading to impairment of food intake and ultimately death due to starvation. The pathogen was successfully detected within the lesions by polymerase chain reaction (PCR) and chromogenic in situ hybridization. The epizootic resulted in a significant decline in the Austrian greenfinch population. Continuing passive surveillance in the subsequent years (2013–2020) revealed that the condition occurred each year and was present in the entire country. Genetic characterization of the pathogen showed the presence of an identical strain irrespective of geographical location, bird species, and year.

Assessing rates of parasite coinfection and spatiotemporal strain variation via metabarcoding: insights for the conservation of European Turtle Doves Streptopelia turtur

Understanding the frequency, spatiotemporal dynamics and impacts of parasite coinfections is fundamental to developing control measures and predicting disease impacts. The European turtle dove (Streptopelia turtur) is one of Europe's most threatened bird species. High prevalence of infection by the protozoan parasite Trichomonas gallinae has previously been identified, but the role of this and other coinfecting parasites in turtle dove declines remains unclear. Using a high‐throughput sequencing approach, we identified seven strains of T. gallinae, including two novel strains, from ITS1/5.8S/ITS2 ribosomal sequences in turtle doves on breeding and wintering grounds, with further intrastrain variation and four novel subtypes revealed by the iron‐hydrogenase gene. High spatiotemporal turnover was observed in T. gallinae strain composition, and infection was prevalent in all populations (89%–100%). Coinfection by multiple Trichomonas strains was rarer than expected (1% observed compared to 38.6% expected), suggesting either within‐host competition, or high mortality of coinfected individuals. In contrast, coinfection by multiple haemosporidians was common (43%), as was coinfection by haemosporidians and T. gallinae (90%), with positive associations between strains of T. gallinae and Leucocytozoon suggesting a mechanism such as parasite‐induced immune modulation. We found no evidence for negative associations between coinfections and host body condition. We suggest that longitudinal studies involving the recapture and investigation of infection status of individuals over their lifespan are crucial to understand the epidemiology of coinfections in natural populations.

Endoparasitoses of the Eurasian collared dove (Streptopelia decaocto) on the northern Black Sea coast of Ukraine

One of the main tasks of ecological parasitology at the present stage is to determine patterns of spread of invasive diseases of poultry in the environment through a thorough epidemiological examination, as well as to determine the main directions and factors of spread of parasites in Ukraine. Some pigeon health problems can affect their populations, but parasitic infections play an important role. Our research found that 83.3% of Eurasian collared doves examined (Streptopelia decaocto) were affected by endoparasites. The commonest helminths were Raillietina spp. with the average invasion intensity of 4.9 ± 1.3 specimens/ind., Baruscapillaria spp. and Ascaridia columbae with an invasion intensity of 4.6 ± 1.5 and 3.7 ± 2.1 specimens/ind., respectively. The commonest cestodes were Raillietina spp. with the extent of invasion of 52.2% and Davainea proglottina – 6.7%. The Amoebotaenia cuneata cestodes were recorded in 3 (3.3%) doves, and Echinolepis carioca – only in 2 (2.2%) doves. Six doves (6.7%) were infected with the nematode Ascaridia columbae and 5 (5.6%) – Baruscapillaria spp. Eimerian oocysts were found in 9 (10%) collared doves, and Trichomonas gallinae was recorded in 15 (16.7%) birds. According to the results of helminthological autopsy and identification of the isolated pathogens, 8 varieties of mixinvasions were identified. In association with the Rayetins, there were the protozoa Eimeria spp. and Trichomonas gallinae and the nematode Ascaridia columbae. Two-component invasions were registered in 78.6% of doves, three-component infestations in 14.3% and four-component infestations in 7.1% of birds. Mixed infection with Raillietina spp. + Ascaridia columbae was found in the small intestine of Streptopelia decaocto, which was also pathomorphologically observed to have catarrhal-hemorrhagic enteritis, which was accompanied by the formation of a large number of spotted hemorrhages on the mucous membrane, and in the places of attachment of cestodes - necrotic-caseous areas. Temperature and other weather conditions such as humidity, precipitation, etc. of the northern Black Sea coast affect the population size of intermediate host cestodes. Continuous monitoring of invasive diseases of pigeons of different species will help to take the necessary preventive measures against endoparasitoses of birds.

Endoparasitoses of the Eurasian collared dove (Streptopelia decaocto) on the northern Black Sea coast of Ukraine

One of the main tasks of ecological parasitology at the present stage is to determine patterns of spread of invasive diseases of poultry in the environment through a thorough epidemiological examination, as well as to determine the main directions and factors of spread of parasites in Ukraine. Some pigeon health problems can affect their populations, but parasitic infections play an important role. Our research found that 83.3% of Eurasian collared doves examined (Streptopelia decaocto) were affected by endoparasites. The commonest helminths were Raillietina spp. with the average invasion intensity of 4.9 ± 1.3 specimens/ind., Baruscapillaria spp. and Ascaridia columbae with an invasion intensity of 4.6 ± 1.5 and 3.7 ± 2.1 specimens/ind., respectively. The commonest cestodes were Raillietina spp. with the extent of invasion of 52.2% and Davainea proglottina – 6.7%. The Amoebotaenia cuneata cestodes were recorded in 3 (3.3%) doves, and Echinolepis carioca – only in 2 (2.2%) doves. Six doves (6.7%) were infected with the nematode Ascaridia columbae and 5 (5.6%) – Baruscapillaria spp. Eimerian oocysts were found in 9 (10%) collared doves, and Trichomonas gallinae was recorded in 15 (16.7%) birds. According to the results of helminthological autopsy and identification of the isolated pathogens, 8 varieties of mixinvasions were identified. In association with the Rayetins, there were the protozoa Eimeria spp. and Trichomonas gallinae and the nematode Ascaridia columbae. Two-component invasions were registered in 78.6% of doves, three-component infestations in 14.3% and four-component infestations in 7.1% of birds. Mixed infection with Raillietina spp. + Ascaridia columbae was found in the small intestine of Streptopelia decaocto, which was also pathomorphologically observed to have catarrhal-hemorrhagic enteritis, which was accompanied by the formation of a large number of spotted hemorrhages on the mucous membrane, and in the places of attachment of cestodes - necrotic-caseous areas. Temperature and other weather conditions such as humidity, precipitation, etc. of the northern Black Sea coast affect the population size of intermediate host cestodes. Continuous monitoring of invasive diseases of pigeons of different species will help to take the necessary preventive measures against endoparasitoses of birds.

Sequence subtyping of Trichomonas gallinae from Bonelli's eagle (Aquila fasciata) during four years (2014-2017) reveals that MLS type is associated with lesions

Avian trichomonosis is a parasitic disease that affects wild birds. The objective of this work was to determine the importance of avian trichomonosis in Bonelli's eagles to improve conservation measures in this population. One hundred and eighty-eight birds were studied: 181 chicks, two juveniles, one subadult and four adults. The birds were externally examined and gross lesions at the oropharynx registered. Samples from the oropharyngeal cavity were obtained for Trichomonas spp. detection by culture and PCR, and positive samples were subjected to a multilocus sequence typing approach, including the ITS1/5.8S/ITS2 region (ITS), ribosomal RNA small subunit (18S) and Fe-hydrogenase gene (FeHyd). Global prevalence of T. gallinae infection was 37.8% in total, 45.5% in nestlings. Thirty-three percent of the birds developed lesions that ranged from mild (n = 41) to moderate (n = 14) or severe (n = 7). Multilocus sequence typing analysis showed five different MLS types, ITS-A/18S-VI/FeHyd-A1 and ITS-D/18S-II/Fe-C4 being the most frequent. An association between ITS-A/18S-VI/FeHyd-A1 and moderate or severe lesions was observed, but birds with type ITS-A/18S-VI/FeHyd-A2 also developed lesions. On the contrary, birds with MLS type ITS-D/18S-II/FeHyd-C4 displayed only a low proportion of mild lesions. Chicks raised in nests were at higher risk for T. gallinae infection and development of lesions than chicks raised in captivity. Discordances between samples cultured in TYM and samples subjected to PCR from oropharyngeal swabs were observed, swab-ITS-PCR being more sensitive.RESEARCH HIGHLIGHTS45.5% of Bonelli's eagles in the nest carried T. gallinae and 39.4% showed lesions.PCR from oral swabs showed higher sensitivity than culture in TYM for detection of T. gallinae.MLS types ITS-A/18S-VI/Fe-A1 (and A2) are a risk factor for the development of lesions.

The Prevalence of Tetratrichomonas spp. in Reproductive Geese Flocks

Tetratrichomonas is a genus of parasites that usually inhabits the lower digestive tract, especially the cecum, of various bird species. The infection might lead to birds' death, but in many cases it could be asymptomatic or with mild clinical signs which might be not observed. Subclinical infections can be undiagnosed, leading to production losses. To investigate the prevalence of Tetratrichomonas spp. in geese, 23 cloacal swabs were taken from each of 43 flocks of reproductive geese from five major geese production provinces in Poland after first, second, or third laying season. The obtained swabs were placed in culture medium for propagation of the parasite. All cultures were screened microscopically before PCR was applied to detect the parasites' DNA. After cultivation, the presence of genetic material of Tetratrichomonas was found in 430 out of 989 samples, which correspond to 38 (88.4%) of 43 flocks. The study shows how the number of laying seasons and the size of the flock in which the birds were kept affects the distribution of protozoa of the genus Tetratrichomonas in geese reproductive flocks in Poland.

Haemoproteosis and avian malaria in Columbidae and Corvidae from Iran

Avian malaria (Plasmodium) and related genera (Haemoproteus and Leucocytozoon) are diverse and widespread parasites. Despite the extent of knowledge on avian haemosporidian parasites, information about domestic and wild bird's blood parasites is overall insufficient in Iran. Prevalence of the haemosporidian parasites’ and phylogenetic relationship of lineages are studied by using molecular and morphological results of 152 examined hosts belonging to 17 species. Molecular analysis for haemosporidian detections demonstrated overall prevalence 22.36%. Inspected hosts mostly belonging to Common Pigeons (Columba livia) parasitized by Haemoproteus spp., and Hooded Crows (Corvus cornix) and Carrion Crow (C. corone) were identified as hosting Plasmodium spp. Detected lineages COLIV03, COQUI05, LINN01, ROFI04 and SGS01 are identified as new reports from Iran. We detected no evidence of Leucocytozoon lineages, while the high prevalence of H. columbae was found in Common Pigeons. Such investigation on avian blood parasites contributes to providing new information on the prevalence, epidemiology and geographical distribution of haemosporidian parasites circulating in domestic, pets and wild birds.

Parasites of domestic and wild pigeons in the south of Ukraine

Pigeons are closely related to human life and are both a source of food and object for hobbies and sports. Parasitic diseases of birds are the main reason for their growth retardation, reduced productivity and viability. The article presents the results of studying the prevalence of trichomonosis, cestodes and nematodes among the population of wild and domestic pigeons in the south of Ukraine. According to the results of the conducted researches it is established that in the south of Ukraine endoparasitoses of domestic and wild pigeons are quite widespread, and all species of this bird are carriers of Trichomonas gallinae. At the same time, the highest rate of Trichomonas infection was recorded in Columba palambus and C. livia domestica, and the overall infestation of males is higher by 4.4% compared to females. It was determined that domestic pigeons C. livia domestica were infested with trichomonosis (27.5%) and nematodes (Ascaridia columbae, 57.1%), C. palambus – trichomonosis (32.1%) and cestodes (Raillietina spp., 82.4%), Streptopelia turtur – cestodes (Raillietina spp., 12.5%) and S. decaocto – cestodes (Raillietina spp., 71.4%) and nematodes (Heterakis gallinarum, A. columbae – 33.3% and 44.4% respectively). The overall rate of infestation of pigeons with cestodes was 28.4% and the incidence in males was higher by 3.9% compared to females. It was found that the most common species among pigeon cestodes is Raillietina spp. In addition, 22.9% of pigeons are carriers of nematodes (H. gallinarum, A. columbae and Capillaria spp.). Continuous monitoring of pigeon parasites is necessary because they, in most cases, come into contact with other species of poultry and are a source of general invasion. In terms of further research, it would be promising to study the prevalence of helminthic infestation among wild migratory birds.

Molecular characterization of Trichomonas gypaetinii isolated from the upper alimentary tract of Steller's sea eagles (Haliaeetus pelagicus) and white-tailed sea eagles (Haliaeetus albicilla) in Hokkaido, Japan

Recent phylogenetic and morphologic studies of Trichomonas spp. suggests that there are more than 3 species that infect the upper alimentary tract of wild birds, which include T. gallinae, T. stableri, and T. gypaetinii. In this study, investigations were conducted on the prevalence of trichomonads in the upper alimentary tract of 12 Steller's sea eagles (Haliaeetus pelagicus) and 18 white-tailed sea eagles (H. albicilla). All birds were rescued from the wild and kept at a rehabilitation facility in Hokkaido, Japan, for variable durations and did not show any symptoms of trichomonosis. The ITS1-5.8SrRNA-ITS2 (ITS) genomic region of Trichomonas spp. was detected from 29 samples by PCR, and flagellates were confirmed from 4 samples by culture. Morphologic observations and measurement recordings were conducted under a light microscope on trophozoites obtained from the cultured isolates. Genomic sequences of the ITS, 18S ribosomal RNA (18S rRNA), Fe-hydrogenase, and RNA polymerase II largest subunit (Rpb1) regions were determined by direct sequencing, and phylogenetic analyses were conducted with previously published sequences of Trichomonas spp. All isolates were concluded as T. gypaetinii based on morphologic and molecular characterizations of the ITS and 18S rRNA genes. This is the first study to isolate T. gypaetinii from Haliaeetus eagles and further provide novel sequences of the Fe-hydrogenase and Rpb1 genes of T. gypaetinii. Both genomic regions also confirmed that T. gypaetinii belong to independent clusters from other Trichomonas spp.

Trichomonas gallinae Identification and Histopathological Study in Pigeon (Columba livia domestica) in Baghdad City, Iraq

Trichomonas gallinae causes avian trichomoniasis, which is one of the most common protozoan infections in birds worldwide. Therefore, this study was conducted to investigate and identify the Trichomonas gallinae in domestic pigeons (Columba livia domestica) by microscopic examination (direct smear and Giemsa stain) and histopathological examination in Baghdad city, Iraq, during the period from beginning of October 2018 to end of March 2019. Giemsa-stained cytoplasm with light purple and nucleus with dark purple, clarification of flagella, nucleus, and cytoplasm very well. Histopathological findings of infected birds showed gross existence of yellowish white caseous necrotic material in the oral cavity and esophagus. The histopathological examination in the larynx, esophagus, trachea, crop, liver, and lung as infiltration of inflammatory cell mainly (heterophils); thickening of mucosa because of extensive infiltration of heterophils and disruption of esophageal gland; the thickness in bronchi wall of lung due to glandular hyperplasia and muscular fibroplasia, in liver focal necrosis of parenchyma with mononuclear cell (MNCs) infiltration and granuloma composed of MNCs and heterophils. The current study may contribute to determining the histopathological changes of esophagus, trachea, crop, and liver of trichomoniasis- infected pigeons.

Molecular detection and genetic characterization of Trichomonas gallinae in falcons in Saudi Arabia

Avian trichomonosis is primarily caused by Trichomonas gallinae, a flagellated protozoan parasite that especially infects the upper digestive tract of columbid bird species and their avian predators. However, this parasite has recently been found to be distributed worldwide in various other avian species. This parasitic disease is common in captive falcons in Saudi Arabia and the Middle East. This study aimed to examine and identify the genetic variation of T. gallinae obtained from three species of falcons in Saudi Arabia via the sequencing analysis of the internal transcribed spacer (ITS) region. Swab samples from 97 saker falcons (Falco cherrug), 24 peregrine falcons (Falco peregrinus) and 37 gyrfalcons (Falco rusticolus) were cultured and analysed for infection between 2018 and 2019. The overall prevalence of infection by T. gallinae was 26.58% (n = 42), of which 35 (83.33%) were collected from Riyadh region and seven (16.67%) were collected from Qassim region. The results indicate the presence of four genotypes of T. gallinae in Saudi falcons: A, C, II, and KSA11. This study reports for the first time genetic diversity of T. gallinae in these falcons in Saudi Arabia.

Detection of Trichomonas gallinae in Wild Birds Admitted to a Rehabilitation Center, Florida, USA

We screened raptors (n=188) and columbids (n=2) presenting to a Tampa, Florida, US rehabilitation center from June 2016 to April 2017 for Trichomonas gallinae. One juvenile Cooper's Hawk (Accipiter cooperii) was culture- and PCR-positive and sequencing identified as genotype E1. A subset of culture-negative (10%, n=19) samples were negative via PCR.

Multilocus Analysis Resolves the European Finch Epidemic Strain of Trichomonas gallinae and Suggests Introgression from Divergent Trichomonads

In Europe, Trichomonas gallinae recently emerged as a cause of epidemic disease in songbirds. A clonal strain of the parasite, first found in the United Kingdom, has become the predominant strain there and spread to continental Europe. Discriminating this epidemic strain of T. gallinae from other strains necessitated development of multilocus sequence typing (MLST). Development of the MLST was facilitated by the assembly and annotation of a 54.7 Mb draft genome of a cloned stabilate of the A1 European finch epidemic strain (isolated from Greenfinch, Chloris chloris, XT-1081/07 in 2007) containing 21,924 protein coding genes. This enabled construction of a robust 19 locus MLST based on existing typing loci for Trichomonas vaginalis and T. gallinae. Our MLST has the sensitivity to discriminate strains within existing genotypes confidently, and resolves the American finch A1 genotype from the European finch epidemic A1 genotype. Interestingly, one isolate we obtained from a captive black-naped fruit dove Ptilinopsus melanospilus, was not truly T. gallinae but a hybrid of T. gallinae with a distant trichomonad lineage. Phylogenetic analysis of the individual loci in this fruit dove provides evidence of gene flow between distant trichomonad lineages at 2 of the 19 loci examined and may provide precedence for the emergence of other hybrid trichomonad genomes including T. vaginalis.

Trichomonosis in Greenfinches (Chloris chloris) in the Netherlands 2009-2017: A Concealed Threat

Finch trichomonosis in Europe is caused by a Trichomonas gallinae subtype A1 strain, considered to be clonal because lacking genetic heterogeneity in partial genotyping. The disease recently emerged and has been associated with a 66% reduction of the British breeding greenfinch (Chloris chloris) population. In contrast, in the Netherlands, where trichomonosis was detected in 2009, the breeding greenfinch population continued to grow in subsequent years. This study aimed to elucidate whether this discrepancy in population trends is because Trichomonas infection in Dutch greenfinches is associated with less severe disease, i.e., disease being less fatal. Therefore, it characterized and quantified trichomonosis in a convenience sample of greenfinches found dead and examined post-mortem between 2009 and 2017 and compared results to published data from Great Britain. Trichomonads were detected by cytology, histology, or culture in 95/101 greenfinches. The birds with trichomonads all had microscopic lesions in the upper digestive tract consistent with trichomonosis, indicating the trichomonads caused disease. The occurrence of significant lesions due to other causes was low. Some greenfinches with trichomonosis showed no macroscopic lesions. These birds showed significantly less ulceration of the mucosa and less extensive heterophil infiltration, but extent of macrophage infiltration and presence of bacteria was similar to that of birds with macroscopic lesions, and significant lesions due to other causes were equally rare. Therefore, trichomonosis was considered similarly fatal in both groups. The frequency of fatal trichomonosis in the Dutch greenfinches did not differ significantly from that reported from Great Britain. Partial genotyping of the ITS1-5,8S-ITS2 and Fe-hydrogenase regions of T. gallinae was performed to detect genetic heterogeneity, that could indicate the presence of other, possibly less virulent, strains. In 60/63 samples there was full alignment of sequences with the clonal strain of T. gallinae subtype A1. The remaining three samples had the same single synonymous nucleotide difference in the Fe-hydrogenase region; however, pathology is these three was identical to the others. Collectively, the results provide no clear evidence for less severe disease as explanation for the discrepancy in census data trends. We conclude that trichomonosis is a threat concealed in Dutch breeding greenfinch census data.

The raptor Chimango Caracara (Milvago chimango) (Aves: Falconiformes) - A new host for Trichomonas gallinae (protozoa: Trichomonadidae)

This work describes a specimen of Chimango Caracara (Milvago chimango - Vieillot, 1816), from southern Brazil, as a new natural host for Trichomonas gallinae (Rivolta, 1878). Caseous oral lesions were observed in a young bird, and the parasite was isolated in modified Diamond’s media. Morphology of the parasite was evaluated through microscopy and subsequently, sequencing of the internal transcribed spacer 1 (ITS1) of ribosomal DNA was performed to confirm T. gallinae identification. As far as authors are concerned, this is the first report of Milvago chimango as a natural host for T. gallinae.

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This is the first report of Milvago chimango as a natural host for T. gallinae.

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The in vitro culture and molecular analysis allowed the confirmation of the diagnosis of trichomonosis.

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Wild species adapted to urban environments may pose new risks to the wild fauna.

Prevalence of Trichomonas gallinae infection in Pigeon of Jessore District, Bangladesh

Objective:

This study was conducted to estimate the prevalence of Trichomonas gallinae infection in pigeon and determination of spatial factors related with T. gallinae infection among smallholder farms at Abhaynagar and Monirampur Upazillas, Jessore District, Bangladesh.

Materials and Methods:

This cross-sectional study has undertaken from November 24, 2017 to February 28, 2018 on randomly selected 60 pigeons from 12 smallholder farms. Wet smear technique has been used to identify T. gallinae, from swab samples collected from oropharynx and crop of the sampled birds.

Results:

The overall prevalence was 60% (95% CI: 46.5–72.4) in which 75% (95% CI: 55.1–89.3), 50% (95% CI: 23.0–76.9), and 44.4% (95% CI: 21.5–69.2) were in squab, adult male, and adult female, respectively. The prevalence, in the case of dead pigeons (n = 13), 69.2% showed positive to the protozoan infection in the study. On the basis of spatial distribution, T. gallinae infection in the rural area was 64% (n = 25) followed by urban area 57.1% (n = 35) of the district. The prevalence of T. gallinae was insignificantly higher at Abhaynagar upazilla in contrast to Monirampur upazilla (30%) of Jessore district.

Conclusion:

This research finding suggests that a significant level of (57.4%) T. gallinae infection is circulating among the pigeon population of Bangladesh. Therefore, proper housing, feeding, and disease management should be ensured by the owner to prevent this problem.

Membrane associated proteins of two Trichomonas gallinae clones vary with the virulence

Oropharyngeal avian trichomonosis is mainly caused by Trichomonas gallinae, a protozoan parasite that affects the upper digestive tract of birds. Lesions of the disease are characterized by severe inflammation which may result in fatality by starvation. Two genotypes of T. gallinae were found to be widely distributed in different bird species all over the world. Differences in the host distribution and association with lesions of both genotypes have been reported. However, so far no distinct virulence factors of this parasite have been described and studies might suffer from possible co-infections of different genotypes. Therefore, in this paper, we analyzed the virulence capacity of seven clones of the parasite, established by micromanipulation, representing the two most frequent genotypes. Clones of both genotypes caused the maximum score of virulence at day 3 post-inoculation in LMH cells, although significant higher cytopathogenic score was found in ITS-OBT-Tg-1 genotype clones at days 1 and 2, as compared to clones with ITS-OBT-Tg-2. By using one representative clone of each genotype, a comparative proteomic analysis of the membrane proteins enriched fraction has been carried out by a label free approach (Data available via ProteomeXchange: PXD013115). The analysis resulted in 302 proteins of varying abundance. In the clone with the highest initial virulence, proteins related to cell adhesion, such as an immuno-dominant variable surface antigen, a GP63-like protein, an armadillo/beta-catenin-like repeat protein were found more abundant. Additionally, Ras superfamily proteins and calmodulins were more abundant, which might be related to an increased activity in the cytoskeleton re-organization. On the contrary, in the clone with the lowest initial virulence, larger numbers of the identified proteins were related to the carbohydrate metabolism. The results of the present work deliver substantial differences between both clones that could be related to feeding processes and morphological changes, similarly to the closely related pathogen Trichomonas vaginalis.

Parasitological and molecular survey of scattered parasitism by trichomonads in some avian species in Iran

Outbreaks of avian trichomonosis are being reported worldwide; meanwhile, the genetic and virulence variations are under investigation. In this study, the occurrence and genetic variability of oral or faecal trichomonads among various avian species were investigated. Samples obtained from either the oropharyngeal cavity, crop/oesophagus, droppings/cloaca, or conjunctival swabs of avian species were inspected for flagellates. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples was performed to investigate the genetic diversity of the isolates. Investigation of 737 birds revealed an infection rate of 15.7% in the upper gastrointestinal tract, 7.3% in the faecal samples, and 0.7% involvement of the conjunctiva. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples, identified genotypes A and B of Trichomonas gallinae and genogroups A-C and E of Tetratrichomonas gallinarum. A novel ITS genotype of intestinal trichomonads was also detected in hooded crow (Corvus cornix) and common mynah (Acridotheres tristis). In the present study, in addition to Columbiformes and Falconiformes, trichomonads were detected in Passeriformes and Galliformes with the involvement of organs other than the gastrointestinal tract. Genotype A T. gallinae was detected in domestic pigeons (Columba livia domestica), a laughing dove (Spilopelia senegalensis), a common kestrel (Falco tinnunculus), a budgerigar (Melopsittacus undulates), and a canary (Serinus canaria). Distinct genotype B was detected in a common mynah and a budgerigar. Genogroups A-C of T. gallinarum were also demonstrated in Galliformes and Anseriformes. Furthermore, two novel trichomonad ITS genotypes were detected in hooded crows and a common mynah warranting detailed multi-locus molecular analysis.RESEARCH HIGHLIGHTSITS diversity of trichomonads was shown in various avian species.Diversity of the parasites' target organ and clinical manifestations was demonstrated.Two novel ITS genotype trichomonads from common mynah and hooded crow were identified.

Tetratrichomonas and Trichomonas spp.-Associated Disease in Free-Ranging Common Eiders ( Somateria mollissima) from Wellfleet Bay, MA and Description of ITS1 Region Genotypes

During an outbreak of Wellfleet Bay virus (WFBV) in common eiders ( Somateria mollissima) from the Cape Cod region of Massachusetts, several birds were diagnosed with trichomonosis consisting of multiple trichomonad species. Six birds were examined, with trichomonads found in ceca in four birds and associated typhlitis in three of these four birds. PCR and DNA sequencing utilizing trichomonad-specific primers targeting the ITS1 region of the ribosomal DNA (rDNA) revealed the presence of Tetratrichomonas gallinarum in the gastrointestinal tracts of five birds and Trichomonas spp. in the livers of two birds, one of which had a dual Te. gallinarum-Trichomonas gallinae infection. Sequence analysis revealed no variation between Te. gallinarum sequences whereas the ITS1 sequences obtained from the other Trichomonas spp. demonstrated the presence of multiple genotypes. One sequence had 100% identity to a Trichomonas sp. previously isolated from a Cooper's hawk ( Accipiter cooperii) and the other sequence was 100% identical to a previously described Tr. gallinae isolate obtained from a Pacific Coast band-tailed pigeon ( Patagioenas fasciata monilis). These findings suggest Te. gallinarum and other Trichomonas spp. possibly contributed to morbidity and mortality in this species. Furthermore, to the authors' knowledge, this is the first report of trichomonad-associated disease in a free-ranging sea duck.

Improved subtyping affords better discrimination of Trichomonas gallinae strains and suggests hybrid lineages

Trichomonas gallinae is a protozoan pathogen that causes avian trichomonosis typically associated with columbids (canker) and birds of prey (frounce) that predate on them, and has recently emerged as an important cause of passerine disease. An archived panel of DNA from North American (USA) birds used initially to establish the ITS ribotypes was reanalysed using Iron hydrogenase (FeHyd) gene sequences to provide an alphanumeric subtyping scheme with improved resolution for strain discrimination. Thirteen novel subtypes of T. gallinae using FeHyd gene as the subtyping locus are described. Although the phylogenetic topologies derived from each single marker are complementary, they are not entirely congruent. This may reflect the complex genetic histories of the isolates analysed which appear to contain two major lineages and several that are hybrid. This new analysis consolidates much of the phylogenetic signal generated from the ITS ribotype and provides additional resolution for discrimination of T. gallinae strains. The single copy FeHyd gene provides higher resolution genotyping than ITS ribotype alone. It should be used where possible as an additional, single-marker subtyping tool for cultured isolates.

An outbreak of trichomonosis in European greenfinches Chloris chloris and European goldfinches Carduelis carduelis wintering in Northern France

Avian trichomonosis is a common and widespread disease, traditionally affecting columbids and raptors, and recently emerging among finch populations mainly in Europe. Across Europe, finch trichomonosis is caused by a single clonal strain of Trichomonas gallinae and negatively impacts finch populations. Here, we report an outbreak of finch trichomonosis in the wintering populations of Chloris chloris (European greenfinch) and Carduelis carduelis (European goldfinch) from the Boulonnais, in northern France. The outbreak was detected and monitored by bird ringers during their wintering bird ringing protocols. A total of 105 records from 12 sites were collected during the first quarter of 2017, with 46 and 59 concerning dead and diseased birds, respectively. Fourteen carcasses from two locations were necropsied and screened for multiple pathogens; the only causative agent identified was T. gallinae. Genetic characterization was performed by four markers (small subunit ribosomal RNA, hydrogenosomal iron-hydrogenase, and RNA polymerase II subunit 1 genes, and the internal transcribed spacers (ITS) region) and confirmed the T. gallinae strain to be A1, which affects the finch populations of Europe. This was also confirmed by an ITS-based phylogenetic analysis which further illustrated the diversity of the Trichomonas infecting birds. Preliminary data on the survival and dispersion of infected birds were obtained from ring-returns of diseased individuals. The anthropogenic spread of diseases through bird feeding practices is highlighted and some suggestions to prevent pathogen transmission via backyard supplementary feeders for garden birds are given.

Artificially decreased dissolved oxygen increases the persistence of Trichomonas gallinae in water

Water containing organic material has been shown to increase the persistence of the avian pathogenic protozoa, Trichomonas gallinae. We hypothesized that the decrease in dissolved oxygen due to microbes in the organic material could increase persistence of the microaerophilic trichomonads. Using simulated birdbaths, we determined 1) the levels of dissolved oxygen in distilled water with various amounts of organic material, 2) the concentration of the oxygen-scavenging enzyme Oxyrase^® needed to achieve the dissolved oxygen levels obtained in organic material contaminated water, and finally, 3) the persistence of two T. gallinae isolates in Oxyrase®-supplemented water. An average of 9.6% dissolved oxygen was obtained with the addition of 15 g organic material to 500 ml of distilled water, whereas organic material-free water had 86.2% dissolved oxygen. The addition of 0.5% and 1.0% (vol/vol) Oxyrase^® to organic material-free water yielded dissolved oxygen of 18.6% and 6.9%, respectively. Using 0.5% and 1.0% concentrations of Oxyrase^®, we evaluated the persistence of two trichomonad isolates by inoculating ∼1 million trichomonads into 500 ml distilled water in triplicate. At various time-points, 0.5 ml aliquots of trichomonad-inoculated water were obtained and placed into Hollander Fluid media, incubated at 37 °C, and read by light microscopy every other day for 5 days. In our 1% Oxyrase^® treatments, the longest recorded persistence of broad-winged hawk 1 increased from the previously reported 4hrs to 30hrs and Cooper's hawk 4 from 16hrs to 30hrs. These results indicate that the mechanism for organic material-mediated trichomonad persistence is associated with decreased dissolved oxygen, further demonstrating the importance of keeping birdbaths free of organic debris to discourage trichomonad persistence.

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Low (9.6%) dissolved oxygen (DO) levels were achieved in waterers with addition of organic material (OM).

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Addition of 1% Oxyrase resulted in similar DO findings (6.9%) with a pH of 7.24

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Lower DO is likely mechanism of increased Trichomonas gallinae persistence in waterers with OM.

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Results underscore the need to keep bird waterers clean to minimize T. gallinae transmission.

Trichomonosis due to Trichomonas gallinae infection in barn owls (Tyto alba) and barred owls (Strix varia) from the eastern United States

Trichomonosis is an important cause of mortality in multiple avian species; however, there have been relatively few reports of this disease in owls. Two barn owls (Tyto alba) and four barred owls (Strix varia) submitted for diagnostic examination had lesions consistent with trichomonosis including caseous necrosis and inflammation in the oropharynx. Microscopically, these lesions were often associated with trichomonads and molecular testing, if obtainable, confirmed the presence of Trichomonas gallinae, the species most commonly associated with trichomonosis in birds. The T. gallinae genotype in one barn owl and two barred owls was identified as ITS-OBT-Tg-1 by sequence analysis. Columbids are the primary hosts for T. gallinae, and columbid remains found within the nest box of the barn owls were the likely source of infection. This study is the first to formally describe the strains and genetic variation of T. gallinae samples from clinical cases of trichomonosis in barn and barred owls in the eastern USA.

Prevalence and genotyping of Trichomonas infections in wild birds in central Germany

Avian trichomonosis is a widespread disease in columbids and other birds, caused by ingestion of the unicellular flagellate Trichomonas gallinae which proliferate primarily in the upper respiratory tracts. Studies using genetic analyses have determined some highly pathogenic lineages in birds, but the prevalence and distribution of potentially pathogenic and non-pathogenic T. gallinae lineages in wild birds is still not well known. We examined 440 oral swab samples of 35 bird species collected between 2015 and 2017 in Hesse, central Germany, for Trichomonas spp. infection and for determining the genetic lineages. Of these birds, 152 individuals were caught in the wild and 288 individuals were admitted from the wild to a veterinary clinic. The overall Trichomonas spp. prevalence was 35.6%. We observed significant differences between bird orders, with the highest prevalence in owls (58%) and columbids (50%), while other orders had slightly lower prevalences, with 36% in Accipitriformes, 28% in Falconiformes and 28% in Passeriformes. Among 71 successfully sequenced samples, we found 13 different haplotypes, including two previously described common lineages A/B (20 samples) and C/V/N (36 samples). The lineage A/B has been described as pathogenic, causing lesions and mortality in columbids, raptors and finches. This lineage was found in 11 of the 35 species, including columbids (feral pigeon, woodpigeon, stock dove), passerines (greenfinch, chaffinch, blackbird) and raptors (common kestrel, sparrowhawk, red kite, peregrine falcon and common buzzard). One new lineage (R) was found in a sample of a chaffinch. In conclusion, we found that the prevalence of Trichomonas spp. infection in wild birds was high overall, and the potentially pathogenic lineage A/B was widespread. Our findings are worrying, as epidemic outbreaks of trichomonosis have already been observed in Germany in several years and can have severe negative effects on bird populations. This disease may add to the multiple pressures that birds face in areas under high land-use intensity.

Endemic infection of the common mynah Acridotheres tristis with Trichomonas gallinae the agent of avian trichomonosis

Avian trichomonosis is an architypal disease of wild columbids and those birds that predate them. Increasingly though, it has been reported in passerines; a recent and ongoing epidemic in the chaffinches and greenfinches of Europe and outbreaks amongst house finches, American goldfinches and purple finches in North America. The parasite, Trichomonas gallinae, causes lesions in the upper respiratory tract which can cause mortality associated with dehydration and emaciation. This paper reports for the first time, the widespread, endemic and often asymptomatic infection of common mynah (Acridotheres tristis) around the Faisalabad District, Pakistan. Parasite typing was used to investigate the potential for transmission among the frequently sympatric species. Type C parasites were found in mynah, and while this is analagous to the pandemic finch strain which is Type A, it is the first known example of passerine infections of this parasite genotype. Subtype analysis showed the strain to be C4 a subtype which has a widespread distribution in columbids.

Trichomonas

The most widely known trichomonad in veterinary medicine is Tritrichomonas foetus. It is the etiologic agent of bovine tritrichomonosis, a sexually transmitted disease in extensively managed herds throughout many geographic regions worldwide. The same trichomonad species is also regarded as the causative agent of chronic diarrhea in the domestic cat, although more recent studies observed molecular differences between bovine- and feline-derived T. foetus. Trichomonosis in cats has a worldwide distribution and is mainly present among cats from high-density housing environments. Other trichomonads are found as inhabitants of the gastrointestinal tract in birds, such as Trichomonas gallinae. Particularly, Columbiformes, Falconiformes, Strigiformes, and wild Passeriformes can be severely affected by avian trichomonads. Diagnosis of trichomonosis is often complicated by the fragility of the parasite. To ensure valid test results, it is essential to collect and handle specimens in the right way prior to analysis. Cultivation tests, the specific amplification of parasites, or a combination of both test methods is the most efficient and most commonly used way to diagnose trichomonosis in animals. Bovine tritrichomonosis is mainly controlled by the identification and withdrawal of infected animals from bovine herds. The control of feline and avian trichomonosis relies mainly on preventive measures.

Avian trichomonosis in spotted owls (Strix occidentalis): Indication of opportunistic spillover from prey

Avian trichomonosis, caused by the flagellated protozoan parasite Trichomonas gallinae, has variable pathogenicity among bird species ranging from asymptomatic infections to severe disease periodically manifesting in epidemic mortality. Traditionally, columbids are identified as highly susceptible to infection with occasional spillover into raptors that prey on infected birds. We identified avian trichomonosis in two dead California spotted owls (Strix occidentalis occidentalis) and three dead northern spotted owls (S. o. caurina) in California during 2011–2015; infection was confirmed in four owls by PCR. Pathologic lesions associated with trichomonosis in the owls included caseonecrotic lesions of the upper palate accompanied by oropharyngitis, cellulitis, myositis, and/or sinusitis. Spotted owls are known to mainly feed on small mammals; therefore, the source of infection as well as the significance of the disease in spotted owls is unclear. These owl trichomonosis cases coincided temporally and spatially with three trichomonosis epidemics in band-tailed pigeons (Patagioenas fasciata monilis). The same parasite, T. gallinae subtype A2, was isolated from the spotted owls and band-tailed pigeons, suggesting the owls became infected when opportunistically feeding on pigeons during mortality events. Avian trichomonosis is an important factor in the decline of the Pacific Coast band-tailed pigeon population with near-annual mortality events during the last 10 years and could have conservation implications for raptor species at risk, particularly those that are facing multiple threats.

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Band-tailed pigeons evaluated for trichomonad infections during mortality events.

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Spotted owls evaluated for trichomonad infections coinciding with mortality events.

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Trichomonads characterized using ITS1/5.8S rRNA/ITS2 and Fe-hydrogenase loci.

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Trichomonas gallinae subtype A2 was predominant parasite in both pigeons and owls.

First report of an outbreak trichomoniasis in turkey in Sistan, Iran

In June 2010, in small flock of turkeys (n = 45) that co-bred with domestic hens (n = 30) and pigeons (n = 35), a disease occurred with the clinical signs of pendulum crop, in appetence and loppy wings. Disease had morbidity (10.3 %) and mortality (6/6 %). Three carcasses and two ill turkeys were referred to the Veterinary clinic in Zabol region for diagnosis and treatment of disease. At necropsy, the oral cavity/crop small yellowish-white masses were characterized. Necrosis in mucosal of crop to gizzard increased and in the crop smelly yellowish green secretions were characterized. According to clinical and necropsy, strong suspicion to trichomoniasis was very high so for perfect diagnosing samples were taken from dead and live turkeys. Samples were taken from oral cavity, esophagus and crop mucous membranes indicated Trichomonas spp infection. 9 out of 45 pieces of turkey (20 %), 23 out of 35 pieces pigeons (65.7 %) were infected but the domestic hens were not contaminated. The result of this study indicates that tricomoniasis can be an important disease of turkeys in Iran co-bred with pigeons and domestic hens.

Persistence of Two Isolates of Trichomonas gallinae in Simulated Bird Baths With and Without Organic Material

Trichomonas gallinae, a well-documented protozoan parasite of avian hosts, has been implicated in major passerine mortality events recently and historically throughout the literature. It has been suggested that bird baths and artificial water sources could serve as a source of infection for naive birds; however, trichomonad persistence in water is not well understood. We measured the persistence of T. gallinae isolates from two avian hosts in distilled water and distilled water with the addition of organic material. We inoculated plastic containers in a laboratory setting with 1 × 10(6) trichomonads and then sampled 500 μl from each container at various time points postinoculation (0-20 hr). The 500-μl aliquots were inoculated into flasks with 5 ml of modified Diamond media at each time point. Flasks were incubated at 37 C and examined by light microscopy for five consecutive days for the characteristic movements of live trichomonads. The maximum persistence was 16 hr with a Cooper's hawk (Accipiter cooperii) isolate in the organic material treatment, far longer than the 1 hr persistence previously reported. We show that T. gallinae isolates are capable of persisting for long periods of time in water, illustrating that bird baths may be validated as a potential source of transmission in epidemics.

Trichomonas gallinae Persistence in Four Water Treatments

Trichomonas gallinae is a protozoan parasite commonly found in columbids, passerines, and several raptor species. Although T. gallinae is thought to spread between individuals and across species through shared water sources, little research has been conducted regarding the persistence of T. gallinae in the environment. To determine the persistence of T. gallinae in various communal water sources, we inoculated 1 × 10(6) trichomonads into 500 mL samples of distilled water, quarry water, bird bath water, and rain barrel water in two replicates. Aliquots of 0.5 mL were collected from each source at -1, 0, 15, 30, and 60 min; aliquots were incubated at 37 C and examined for trichomonads by light microscopy for five consecutive days. Live trichomonads were observed in all samples and at all sampling times except prior to inoculation (-1 min). The pH of water sources ranged from an average of 5.9 to 7.4 postsampling. Our findings indicate that T. gallinae can persist for up to 60 min in various water treatments and thus be infectious for birds drinking T. gallinae-contaminated water.

Molecular characterization of Trichomonas gallinae isolates recovered from the Canadian Maritime provinces’ wild avifauna reveals the presence of the genotype responsible for the European finch trichomonosis epidemic and additional strains

Finch trichomonosis, caused by Trichomonas gallinae, emerged in the Canadian Maritime provinces in 2007 and has since caused ongoing mortality in regional purple finch (Carpodacus purpureus) and American goldfinch (Carduelis tristis) populations. Trichomonas gallinae was isolated from (1) finches and rock pigeons (Columbia livia) submitted for post-mortem or live-captured at bird feeding sites experiencing trichomonosis mortality; (2) bird seed at these same sites; and (3) rock pigeons live-captured at known roosts or humanely killed. Isolates were characterized using internal transcribed spacer (ITS) region and iron hydrogenase (Fe-hyd) gene sequences. Two distinct ITS types were found. Type A was identical to the UK finch epidemic strain and was isolated from finches and a rock pigeon with trichomonosis; apparently healthy rock pigeons and finches; and bird seed at an outbreak site. Type B was obtained from apparently healthy rock pigeons. Fe-hyd sequencing revealed six distinct subtypes. The predominant subtype in both finches and the rock pigeon with trichomonosis was identical to the UK finch epidemic strain A1. Single nucleotide polymorphisms in Fe-hyd sequences suggest there is fine-scale variation amongst isolates and that finch trichomonosis emergence in this region may not have been caused by a single spill-over event.

Confidence limits for prevalence of disease adjusted for estimated sensitivity and specificity

Prevalence of a disease is usually assessed by diagnostic tests that may produce false results. Rogan and Gladen (1978) described a method to estimate the true prevalence correcting for sensitivity and specificity of the diagnostic procedure, and Reiczigel et al. (2010) provided exact confidence intervals for the true prevalence assuming sensitivity and specificity were known. In this paper we propose a new method to construct approximate confidence intervals for the true prevalence when sensitivity and specificity are estimated from independent samples. To improve coverage we applied an adjustment similar to that described in Agresti and Coull (1998). According to an extensive simulation study the new confidence intervals maintain the nominal level fairly well even for sample sizes as small as 30; mini-mum coverage is above 88%, 93%, and 98% at nominal 90%, 95%, and 99%, respectively. We illustrate the advantages of the proposed method with real-life applications.

Trichomonas spp. in pigeons: detection by OSOM Trichomonas Rapid Test

The efficacy of the OSOM Trichomonas Rapid Test (developed for rapid diagnosis of human Trichomonas vaginalis) in detection of Trichomonas spp. in pigeons (Columba livia) was investigated. Two oral cavity swabs were taken from 50 farm pigeons. Cultivation in Diamond Trichomonas medium was used as a reference method. According to a morphological determination, Trichomonas gallinae was the only protozoan found; however, no further molecular analysis was conducted. The OSOM Trichomonas test was positive in 39 oral swabs. In comparison with the cultivation method three samples were identified as false negative and one as false positive. Test specificity and sensitivity were established as 93% and 90%, respectively. Using Cohen's Kappa, the concordance between the two testing methods was found to be strong (kappa = 0.7506, 95% CI = 0.5162-0.9850). The OSOM Trichomonas test is not able to distinguish between Trichomonas species; however, results suggest that the test is suitable for the rapid detection of Trichomonas spp. infection in pigeons.