The diagnosis and prevalence of persistent infection with bovine viral diarrhoea virus in feedlot cattle

Bovine viral diarrhoea virus infection is an important viral infection affecting the cattle industry today. The prevalence of this infection in South African feedlots is unknown. Ear notch biopsies were collected from animals entering feedlots which appeared unthrifty, chronic poor doers, and animals entering the hospital pen with respiratory disease for the first time. One thousand and seventy four (1074) samples were collected from the first two categories and 616 samples from animals entering the hospital pen. Samples were processed with routine immunoperoxidase protocol. Serum samples were also collected when possible. The first aim of this study was to determine the prevalence with the use of immunoperoxidase staining on ear notch biopsies. Overall 49 animals tested positive, 43 from the 1074 group and 6 from the 616 group. The prevalence of persistently infected cattle entering the feedlots was determined as 2.9%, which is higher than the rule of thumb that 0.5% of infected animals enter feedlots. Four percent were positive in the group of 1074 animals and one percent in those entering the hospital pen for the first time. It was proposed by the author that persistently infected animals are at a greater risk to develop respiratory disease in the feedlot, but this was not supported by the data collected. There was thus no clear increase in respiratory disease in persistently infected animals. The reliability of the immunoperoxidase stain as a diagnostic method to identify persistently infected animals was also evaluated. This diagnostic method proved to be reliable, but the pathologist needs to be aware of non-specific staining. During the course of the research it became apparent that in some cases mast cells in the dermis stain positive with both DAB and NovaRED stains. Positive staining in keratinocytes and hair follicle epithelium was not present and these cases were proven as negative for persistent infection. The specific cause of positive staining of mast cell granules remains unclear. Only ten positive cases had serum samples on which ELISA tests for antigen and antibody were performed. All tests correlated well with the immunoperoxidase method except in four cases, where the animals were incorrectly diagnosed as positive due to the non-specific staining as described above. Immunoperoxidase staining on ear notch biopsies is thus a reliable diagnostic method to identify persistently infected animals with BVDV, but the pathologist must be aware of non-specific positive staining.Bees virus diarree infeksie is ‘n belangrike virale infeksie wat die bees industrie van vandag beinvloed. Die prevalensie van die infeksie in Suid Afrikaanse voerkrale is onbekend. Oorknip biopsies is geneem van verdagte diere met aankoms by die voerkraal, chroniese swak beeste en diere wat vir die eerste keer in die hospitaal kraal weens respiratoriese siekte opgeneem is. Een duised vier en sewentig (1074) monsters is van die eerste twee kategoriee geneem en 616 monsters van diere wat in die hospitaal kraal opgeneem is. Monsters is op roetiene wyse vir immunoperoksidase kleuring geprosesseer. Serum monsters is waar moontlik ook versamel. Die eerste doel van die studie was om die prevalensie van permanente besmette draers te bepaal met behulp van immunoperoksidase kleuring op oorknip biopsies. Nege-en-veertig diere in totaal het positief getoets, 43 vanuit die eerste groep en 6 vanuit die tweede groep. Die prevalensie van permanente besmette draers wat in voerkrale opgeneem word is was 2.9% wat hoër is as die verwagte 0.5% wat deur die literatuur aangedui word. Vier persent was positief in die 1074 groep en 1% in die groep wat vir die eerste keer in die hospitaal kraal opgeneem is. Dit is deur die navorser voorgestel dat permanente besmette draers ‘n groter risiko het om met respiratoriese siektes in die hospitaal kraal opgeneem te word, maar dit is nie deur die data bevestig nie. Daar was dus geen verhoging in die teenwoordigheid van respiratoriese siektes in geaffekteerde diere nie. Die betroubaarheid van immunoperoksidase kleuring om permanente besmette diere met BVD te identifiseer is ook geevalueer. Die metode is betroubaar gevind, maar die patoloog moet bewus wees van nie-spesifieke kleuring. Gedurende die navorsing het dit aan die lig gekom dat mastselle in die dermis positief kleur met DAB en NovaRED kleuring. Positiewe kleuring was nie in die epidermis of haarfollikel epiteel teenwoordig nie en die die gevalle was negatief vir permanente besmetting. Die spesifieke rede vir positiewe kleuring in mastselle is steeds onduidelik. Slegs 10 positiewe gevalle het serum monsters gehad vir ELISA teenliggaam en antigeen toetse. Die resultate het goed gekorrelleer met die immunoperoksidase kleuring, behalwe in 4 gevalle waar gevalle verkeerd as positief gediagnoseer is as gevolg van nie-spesifieke positiewe kleuring soos beskryf. Immunoperoksidase kleuring is dus ‘n sensitiewe metode om permanente besmette draers met BVDV te identifiseer, mits die patoloog bewus is van nie-spesifieke kleuring wat mag voorkom.Dissertation (MMedVet)--University of Pretoria, 2010.Paraclinical Sciencesunrestricte

Acute Hepatic Necrosis Caused by Salmonella enterica Serotype I 4,5,12:-:1,2 in a Dog.

Acute hepatic necrosis was diagnosed in a dog. Gram staining and fluorescence in situ hybridization identified Salmonella enterica in the liver, subsequently confirmed as S. enterica serotype I 4,5,12:-:1,2. This is the first report of acute hepatic necrosis with liver failure caused by Salmonella in a dog.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1128/JCM.01256-1

Diagnosis and prevalence of persistent infection with bovine viral diarrhoea virus in South African feedlot cattle

Bovine viral diarrhoea virus (BVDV) infection is an important viral infection affecting the cattle industry today. The prevalence of this infection in South African feedlots is unknown. Ear notch biopsies were collected from chronic poor doers and animals that appeared unthrifty upon entering feedlots, as well as animals entering the hospital pen with respiratory disease for the first time. A total of 1690 samples were collected: 1074 from the former category and 616 from the latter. A routine immunohistochemistry staining protocol showed that 49 animals tested positive, of which 43 (4%) came from the feedlot entry group and six (1%) from the hospitalised group. The prevalence of persistently infected cattle from this selected, nonrandom sample entering six large South African feedlots was found to be 2.9%, which is higher than the international rule of thumb that 0.5% of all cattle entering feedlots are persistently infected. There was no clear correlation between persistent infection and respiratory disease. Serum samples were also collected when possible and 10 positive cases were found. Results from enzyme-linked immunosorbent assays for antigen and antibody performed on these sera correlated well with those from the immunohistochemistry staining method in six cases, but in four cases the animals tested falsely positive owing to nonspecific staining. Immunohistochemistry staining on ear notch biopsies is thus a reliable diagnostic method to identify persistently infected animals with BVDV, but the pathologist should be aware of nonspecific positive staining.http://www.ojvr.orgmn201

Computed Tomography Findings of Pigmented Villonodular Synovitis in a Dog

AbstractPigmented villonodular synovitis (PVNS) is a rare benign and usually monoarticular neoplastic lesion arising from the synovium, bursae and tendon sheaths in humans, horses and dogs. Categorization for PVNS in humans includes localized and diffuse forms of PVNS and tenosynovial giant cell tumour (TGCT), although histologically they are the same. The localized form is characterized by discrete nodular lesions, the diffuse form is often intra-articular, infiltrative, affecting the entire synovium with more aggressive behaviour and TGCT occurs along tendon sheaths. Computed tomography (CT) of PVNS is well described in humans but not documented in the veterinary literature. Pigmented villonodular synovitis is not a straightforward diagnosis and CT is useful to further characterize radiographic findings. A representative open surgical biopsy of the synovium is essential to obtaining the diagnosis and ruling out malignancy. Currently, there are no guidelines for the diagnosis of PVNS in dogs or long-term follow-up of these cases. This case report describes the presentation, diagnostic findings, treatment and long-term outcome of a 4-year-old male Labrador Retriever with confirmed PVNS. Clinical outcome was considered fair with the dog's lameness and symptoms remaining stable with medical management 3 years following the initial diagnosis.</jats:p

Cognitive and psychiatric symptom trajectories 2–3 years after hospital admission for COVID-19: a longitudinal, prospective cohort study in the UK

Background: COVID-19 is known to be associated with increased risks of cognitive and psychiatric outcomes after the acute phase of disease. We aimed to assess whether these symptoms can emerge or persist more than 1 year after hospitalisation for COVID-19, to identify which early aspects of COVID-19 illness predict longer-term symptoms, and to establish how these symptoms relate to occupational functioning. Methods: The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study of adults (aged ≥18 years) who were hospitalised with a clinical diagnosis of COVID-19 at participating National Health Service hospitals across the UK. In the C-Fog study, a subset of PHOSP-COVID participants who consented to be recontacted for other research were invited to complete a computerised cognitive assessment and clinical scales between 2 years and 3 years after hospital admission. Participants completed eight cognitive tasks, covering eight cognitive domains, from the Cognitron battery, in addition to the 9-item Patient Health Questionnaire for depression, the Generalised Anxiety Disorder 7-item scale, the Functional Assessment of Chronic Illness Therapy Fatigue Scale, and the 20-item Cognitive Change Index (CCI-20) questionnaire to assess subjective cognitive decline. We evaluated how the absolute risks of symptoms evolved between follow-ups at 6 months, 12 months, and 2–3 years, and whether symptoms at 2–3 years were predicted by earlier aspects of COVID-19 illness. Participants completed an occupation change questionnaire to establish whether their occupation or working status had changed and, if so, why. We assessed which symptoms at 2–3 years were associated with occupation change. People with lived experience were involved in the study. Findings: 2469 PHOSP-COVID participants were invited to participate in the C-Fog study, and 475 participants (191 [40·2%] females and 284 [59·8%] males; mean age 58·26 [SD 11·13] years) who were discharged from one of 83 hospitals provided data at the 2–3-year follow-up. Participants had worse cognitive scores than would be expected on the basis of their sociodemographic characteristics across all cognitive domains tested (average score 0·71 SD below the mean [IQR 0·16–1·04]; p<0·0001). Most participants reported at least mild depression (263 [74·5%] of 353), anxiety (189 [53·5%] of 353), fatigue (220 [62·3%] of 353), or subjective cognitive decline (184 [52·1%] of 353), and more than a fifth reported severe depression (79 [22·4%] of 353), fatigue (87 [24·6%] of 353), or subjective cognitive decline (88 [24·9%] of 353). Depression, anxiety, and fatigue were worse at 2–3 years than at 6 months or 12 months, with evidence of both worsening of existing symptoms and emergence of new symptoms. Symptoms at 2–3 years were not predicted by the severity of acute COVID-19 illness, but were strongly predicted by the degree of recovery at 6 months (explaining 35·0–48·8% of the variance in anxiety, depression, fatigue, and subjective cognitive decline); by a biocognitive profile linking acutely raised D-dimer relative to C-reactive protein with subjective cognitive deficits at 6 months (explaining 7·0–17·2% of the variance in anxiety, depression, fatigue, and subjective cognitive decline); and by anxiety, depression, fatigue, and subjective cognitive deficit at 6 months. Objective cognitive deficits at 2–3 years were not predicted by any of the factors tested, except for cognitive deficits at 6 months, explaining 10·6% of their variance. 95 of 353 participants (26·9% [95% CI 22·6–31·8]) reported occupational change, with poor health being the most common reason for this change. Occupation change was strongly and specifically associated with objective cognitive deficits (odds ratio [OR] 1·51 [95% CI 1·04–2·22] for every SD decrease in overall cognitive score) and subjective cognitive decline (OR 1·54 [1·21–1·98] for every point increase in CCI-20). Interpretation: Psychiatric and cognitive symptoms appear to increase over the first 2–3 years post-hospitalisation due to both worsening of symptoms already present at 6 months and emergence of new symptoms. New symptoms occur mostly in people with other symptoms already present at 6 months. Early identification and management of symptoms might therefore be an effective strategy to prevent later onset of a complex syndrome. Occupation change is common and associated mainly with objective and subjective cognitive deficits. Interventions to promote cognitive recovery or to prevent cognitive decline are therefore needed to limit the functional and economic impacts of COVID-19. Funding: National Institute for Health and Care Research Oxford Health Biomedical Research Centre, Wolfson Foundation, MQ Mental Health Research, MRC-UK Research and Innovation, and National Institute for Health and Care Research.</p