Pathogenesis of an IS/885/00-like (IS/885) strain of variant infectious bronchitis virus (IBV) was examined in one day old specific pathogen free (SPF) and commercial broiler chicks. Chicks were ...humanely euthanized at 3, 6, 9, 12, 15, 21 and 28days post infection (dpi) for necropsy examination, and tissues were collected for histopathology and virus detection by reverse transcription polymerase chain reaction (RT-PCR). Respiratory clinical signs and gross lesions consisting of tracheal caseous exudate and plugs, and swollen kidneys (with or without) urate deposits were observed in SPF and broiler chicks. The onset of disease developed more slowly and were of lesser severity in broiler compared to SPF chicks, reflecting the inhibitory effects of the IBV maternal-antibodies in the broiler chicks or genetic/strain susceptibility, or both. Head swelling was observed in one infected broiler chick at 15dpi and the virus was recovered by RT-PCR and isolation. In the IS/885-infected SPF chicks, cystic oviducts were found in two female chicks. IS/885 was isolated from the cystic fluid. Using ELISA, low to moderate levels of the antibodies to IBV was detected in the SPF compared to broiler infected chicks.
•Pathogenesis of IBV IS/885 was examined in one day old SPF and broiler chicks.•The virus caused respiratory distress, tracheal and kidney lesions in infected chicks.•Head swelling was observed in one infected broiler chick at 15dpi.•Cystic oviducts were found in two female SPF chicks.•IBV IS/885 examined in this study was pathogenic for both SPF and broiler chicks.
► Finch trichomonosis was diagnosed as an emerging infectious disease of British finches in 2005. ► Epidemic mortality due to this novel parasitic infection has occurred in subsequent years. ► ...Sequence and multilocus typing tools were used to compare parasite isolates from bird species. ► There was no evidence of heterogeneity amongst the parasites infecting British passerines. ► A clonal strain of Trichomonas gallinae is the causative agent of finch trichomonosis epidemic.
Trichomonas gallinae is a protozoan parasite that is well characterised as a cause of trichomonosis in columbid and raptor species world-wide. The parasite emerged as a novel infection of British passerines in 2005, leading to epidemic mortality associated with significant declines of breeding populations of greenfinches (Carduelis chloris) and chaffinches (Fringilla coelebs). We characterised the extent of T. gallinae genotypic heterogeneity within the affected wild British avifauna by analysing individual isolates from 17 of the species affected. To do so, we employed improved platform-based multilocus typing tools as well as the hydrogenosomal Fe-hydrogenase gene as a single marker locus for fine-typing. We found no evidence of heterogeneity amongst the parasites infecting British passerines, indicating that a clonal strain of T. gallinae is the causative agent of this emerging infectious disease.
Between 2006 and 2015, a high incidence of dilated cardiomyopathy (DCM) was diagnosed in a captive population of banded mongooses (Mungos mungo) at Chester Zoo, United Kingdom. The aim of this study ...was to characterize DCM in these mongooses in order to raise awareness of this condition and help inform management and clinical decisions. Prospective clinical assessments, including echocardiography, radiography, and cardiac biomarkers, were carried out in four mongooses remaining in the collection. Radiographs from 15 mature mongooses were reviewed and cardiac size and metrics assessed. Ten postmortem reports and the histologic sections from nine of these cases were reviewed for cardiac lesions. Echocardiographic findings were consistent with a diagnosis of preclinical DCM in one out of the four cases assessed, and it was considered equivocal in a second case. Taurine levels were within normal limits for domestic carnivores. Radiographs in seven mongooses showed right-sided or generalized cardiomegaly. The width of the heart in intercostal spaces and vertebral-tracheal angle on the lateral view were the most-discriminatory radiographic variables for diagnosis of cardiac disease. At necropsy, there was gross pathological evidence consistent with DCM in seven out of 10 mongooses examined. Histopathologically, mild multifocal fibrosis and rare intermyofiber edema were observed. This study provides preliminary evidence that DCM occurs in captive banded mongoose, but etiology and wider prevalence need to be determined.
Drowning is infrequently reported as a cause of death of wild birds and such incidents typically involve individual, rather than multiple, birds. Over a 21-year period (1993 to 2013 inclusive), we ...investigated 12 incidents of mortality of multiple (2 - 80+) Common starlings (Sturnus vulgaris) in Great Britain that appeared to be due to drowning. More than ten birds were affected in ten of these reported incidents. These incidents always occurred during the spring and early summer months and usually involved juvenile birds. In all cases, circumstantial evidence and post-mortem examinations indicated drowning to be the most likely cause of death with no underlying disease found. A behavioural explanation seems likely, possibly related to the gregarious nature of this species combined with juvenile inexperience in identifying water hazards. A review of data from the ringed bird recovery scheme across Great Britain (1909-2013 inclusive) of both starlings and Common blackbirds (Turdus merula), also a common garden visitor, identified additional suspected drowning incidents, which were significantly more common in the former species, supporting a species predisposition to drowning. For each species there was a marked seasonal peak from April to August. Drowning should be included as a differential diagnosis when investigating incidents of multiple starling mortality, especially of juveniles.
Rapid development in polymerase chain reaction (PCR) technology has revolutionised the speed and accuracy of many diagnostic assays. However, comparatively few wildlife epidemiological studies use ...quantitative PCR (qPCR) for pathogen detection, even fewer employ an internal control, to ensure confidence in negative results, and PCR’s ability to multiplex and therefore detect several targets in a single reaction is underutilised. Here, we describe the development of two multiplex qPCR assays for the red and grey squirrel that detect the pathogens squirrelpox virus (SQPV) and adenovirus in squirrels (SADV), both of which cause mortality in the red squirrel. Both assays use a section of the squirrel phosphoglycerate kinase gene as an endogenous internal control that identifies and compensates for both, inadequate sampling or PCR inhibition. Tests on infected squirrel tissue demonstrate that simple swab samples (particularly from distal antebrachial skin) are sufficient to detect and identify the relative quantity of SQPV DNA in both squirrel species, while rectal swabs and blood cell pellets can be used to reliably indicate SADV infection. These assays are sensitive and specific with an endogenous internal control providing confidence in negative results and allowing comparison across laboratories. Using such assays should prove advantageous in wildlife studies with limited resources while allowing the maximum data yield.
Display omitted
► First reported cases of renal trematodosis in endangered red bird-of-paradise and Socorro doves. ► Paratanasia bragai identified morphologically and molecularly in several ...previously unreported columbiformes. ► New diagnostics developed from this work will be of direct benefit to the conservation of avian species.
Trematode infections affect a diverse range of avian species and the organs that are parasitised are also very varied. The family Eucotylidae contains seven genera of renal flukes that parasitise various birds. In birds, mild to severe lesions have been reported for species of the genus Paratanaisia, which was originally described from columbiform and galliform specimens collected in South America and has been identified in a number of wild avian species.
This paper investigates eight cases of renal trematode infection at Chester Zoo in the UK due to Paratanaisia bragai in five previously unreported species: red bird-of-paradise, Socorro dove, Mindanao bleeding heart dove, laughing dove and emerald dove. Pathological changes, which varied between species, are discussed. A known intermediate snail host Allopeas clavulinum was present in the enclosures but there was no direct evidence of trematode infection. The size of the snails, possible low prevalence and the difficulty of visualising sporocysts contributed to this. Thus the development and application of further molecular diagnostic markers that can be applied to snail tissues is warranted. Parasite identification was confirmed utilizing DNA amplification from formalin-fixed paraffin-embedded tissues using PCR and trematode specific primers. Sequencing full ssrDNA and D1-D3 lsrDNA confirmed the identity in all cases as P. bragai. However, the short 310bp fragment used provides insufficient variation or sequence length for wider application. The epidemiology, pathology and consequences for the management of these endangered species are discussed. Preliminary work on developing an effective ante mortem diagnostic PCR test kit is also highlighted.
The transmission dynamics of the cowpox virus infection have been quantified in two mixed populations of bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus), through analyses of ...detailed time-series of the numbers of susceptible, infectious and newly infected individuals. The cowpox virus is a zoonosis which circulates in these rodent hosts and has been shown to have an adverse effect on reproductive output. The transmission dynamics within species is best described as frequency dependent rather than density dependent, contrary to the 'mass action' assumption of most previous studies, both theoretical and empirical. Estimation of a transmission coefficient for each species in each population also allows annual and seasonal variations in transmission dynamics to be investigated through an analysis of regression residuals. Transmission between host species is found to be negligible despite their close co-habitation. The consequences of this for the combining ability of hosts as zoonotic reservoirs, and for apparent competition between hosts, are discussed.
Gross lesions on the mucosa of the oesophagus and crop varied from small, focal, yellow nodules, 2 to 4 mm in diameter, to a more diffuse yellow-orange thickening of the mucosa, to more severe masses ...of yellow, orange or white debris overlying areas of deep ulceration and causing partial or complete obstruction of the upper digestive tract ( Fig 1 ).
Suttonella ornithocola, first isolated from the lungs of British tit species in 1996, was found to be a novel bacterium belonging to the family
Cardiobacteriaceae. Comprehensive surveillance of ...garden bird mortality across Great Britain between April 2005 and April 2009 involved post mortem and microbiological examination of 82 tits (Paridae; multiple species) and six long-tailed tits (Aegithalidae;
Aegithalos caudatus).
S. ornithocola was isolated from six birds submitted from six incidents of morbidity and mortality involving Paridae and Aegithalidae species with a wide geographical distribution. The mortality incidents occurred sporadically at low incidence throughout the study period, which suggested that the infection is endemic in native bird populations, with a seasonal peak during early spring. Histopathological examination showed multiple foci of acute pulmonary necrosis associated with Gram-negative cocco-bacillary bacteria. These findings supported the hypothesis that
S. ornithocola is a primary pathogen of tits in Great Britain.
Finch trichomonosis emerged in Great Britain in 2005 and led to epidemic mortality and a significant population decline of greenfinches,
Carduelis chloris
and chaffinches,
Fringilla coelebs
, in the ...central and western counties of England and Wales in the autumn of 2006. In this article, we show continued epidemic spread of the disease with a pronounced shift in geographical distribution towards eastern England in 2007. This was followed by international spread to southern Fennoscandia where cases were confirmed at multiple sites in the summer of 2008. Sequence data of the ITS1/5.8S/ITS2 ribosomal region and part of the small subunit (SSU) rRNA gene showed no variation between the British and Fennoscandian parasite strains of
Trichomonas gallinae
. Epidemiological and historical ring return data support bird migration as a plausible mechanism for the observed pattern of disease spread, and suggest the chaffinch as the most likely primary vector. This finding is novel since, although intuitive, confirmed disease spread by migratory birds is very rare and, when it has been recognised, this has generally been for diseases caused by viral pathogens. We believe this to be the first documented case of the spread of a protozoal emerging infectious disease by migrating birds.
PDF
