Organ distribution of Schmallenberg virus RNA in malformed newborns

A novel orthobunyavirus was first detected in German dairy cows in autumn 2011 and was subsequently found in the brains of malformed lambs, kids and calves in the Netherlands, Germany, Belgium, France, Italy, Great Britain, Luxembourg and Spain. For rapid detection of this novel virus, named Schmallenberg virus, a real time quantitative reverse transcription PCR (RT-qPCR) was developed at the Friedrich-Loeffler-Institut and provided to the federal veterinary state laboratories in Germany. For diagnostic purposes, the organ distribution of this new virus was analyzed in several organs and body fluids of 15 lambs and two calves showing typical malformations. Spleen, cerebrum, meconium, spinal cord, rib cartilage, umbilical cord, placental fluid out of the stomach as well as external placental fluid scraped from the coat of the foetuses were collected during necropsy. All animals were tested RT-qPCR positive in the external placental fluid, and all but one were also RT-qPCR positive in the cerebrum, the umbilical and the spinal cord. Our results suggest that both the external placental fluid and the umbilical cord could be suitable sample materials for the confirmation of an infection with Schmallenberg virus in malformed newborns, at least in lambs. This is of special interest since those samples can be collected very easily on the farm without the need of a necropsy.

[Consensus recommendations of the German Radiology Society (DRG), the German Cardiac Society (DGK) and the German Society for Pediatric Cardiology (DGPK) on the use of cardiac imaging with computed tomography and magnetic resonance imaging]

Cardiac magnetic resonance imaging (MRI) and computed tomography (CT) have been developed rapidly in the last decade. Technical improvements and broad availability of modern CT and MRI scanners have led to an increasing and regular use of both diagnostic methods in clinical routine. Therefore, this German consensus document has been developed in collaboration by the German Cardiac Society, German Radiology Society, and the German Society for Pediatric Cardiology. It is not oriented on modalities and methods, but rather on disease entities. This consensus document deals with coronary artery disease, cardiomyopathies, arrhythmias, valvular diseases, pericardial diseases and structural changes, as well as with congenital heart defects. For different clinical scenarios both imaging modalities CT and MRI are compared and evaluated in the specific context.

Clinical course and pathology in rats (Rattus norvegicus) after experimental cowpox virus infection by percutaneous and intranasal application

Recently, several cases of human cowpox virus (CPXV) infections were reported in France and Germany, which had been acquired through close contact with infected pet rats. The animals exhibited respiratory signs or skin lesions and died shortly after purchase. After natural infection of white rats with CPXV in the USSR in 1978, a peracute pulmonary form, a milder dermal form, and a mixed form exhibiting features of both have been described. To the best of the authors' knowledge, 3 experimental cowpox virus infection studies using rats have been performed to date; however, neither results of histomorphological examinations nor immunohistochemical analyses have yet been reported in rats after experimental infections. To investigate the impact of the infection route on the clinical course, the development of lesions, and tropism, rats were infected intradermally, intranasally, or by a combination of both routes. The authors found a correlation between clinical manifestation, pathology, and infection routes. Intradermal and contact exposure yielded a mild dermal form, characterized by the development of vesiculopustular dermatitis. In contrast, intranasally infected animals died peracutely, showing severe dyspnea. Occasionally, a combination of the dermal and the respiratory form occurred after intranasal infection. Immunohistochemically, CPXV antigen was detected in the epithelial and mesenchymal cells of the upper respiratory tract and affected skin lesions and rarely in mesenchymal cells of lymph nodes. This is the first histomorphological and immunohistochemical analysis of CPXV in rats after experimental infection.

Disease severity declines over time after a wild boar population has been affected by classical swine fever--legend or actual epidemiological process?

Classical swine fever (CSF) is a severe multi-systemic disease that can affect both domestic pigs and wild boar. Past outbreaks in European wild boar involved high-virulent CSF virus (CSFV) strains and were mostly self-limiting. In these cases, morbidity and mortality rates were high in the affected regions. In contrast, endemic infections have been observed in several European wild boar populations in recent decades. Morbidity and mortality rates were much lower despite the fact that outbreaks were still detected via diseased or fallen animals. The virus strains involved were mostly classified as genotype 2.3 strains of moderate virulence causing age-dependent disease outcomes. The mechanisms leading to the establishment and perpetuation of endemicity are still not fully understood, but the factor "moderate virulence" seems to be of considerable importance. In this study, we aim to clarify whether the perception of declined 'CSF severity' could hypothetically reflect the adaptation of an initially high-virulent virus or whether this might be better explained as a misinterpretation of observations. A mechanistic eco-epidemiological model was employed to follow up a highly virulent strain of CSFV introduced into large connected wild boar populations. In the model, the virulence of the CSF virus is represented by case mortality and life expectancy after lethal infection. Allowing for small stochastic variation, these two characteristics of the virus are passed on with every new simulated infection that occurs. Model analysis revealed a decrease from high to moderate case mortality within a few years of simulated perpetuation of the virus. The resulting mortality corresponded to the level where the population average of the infectious period and the basic reproduction number of the disease were maximal. This shift in virulence was sufficient to prolong virus circulation considerably beyond the epidemic phase of the simulated outbreaks. Alternative mechanistic explanations for the decrease in disease severity in a CSF-affected wild boar population were evaluated in the light of the simulation experiments and the available epidemiological or virological evidence. In conclusion, the current virus isolates of subgroup 2.3 might be the ideally adapted variants of the CSF virus for long-term perpetuation in wildlife and indeed may have evolved (once) during past outbreaks in large populations. A repeated perception of a declining severity of disease pattern during the course of a CSF outbreak, however, favours the explanation based on monitoring and detection biases rather than repeated observation of selection against highly virulent virus during the time of virus perpetuation.

MRI of the lung (2/3). Why … when … how?

BACKGROUND

Among the modalities for lung imaging, proton magnetic resonance imaging (MRI) has been the latest to be introduced into clinical practice. Its value to replace X-ray and computed tomography (CT) when radiation exposure or iodinated contrast material is contra-indicated is well acknowledged: i.e. for paediatric patients and pregnant women or for scientific use. One of the reasons why MRI of the lung is still rarely used, except in a few centres, is the lack of consistent protocols customised to clinical needs.

METHODS

This article makes non-vendor-specific protocol suggestions for general use with state-of-the-art MRI scanners, based on the available literature and a consensus discussion within a panel of experts experienced in lung MRI.

RESULTS

Various sequences have been successfully tested within scientific or clinical environments. MRI of the lung with appropriate combinations of these sequences comprises morphological and functional imaging aspects in a single examination. It serves in difficult clinical problems encountered in daily routine, such as assessment of the mediastinum and chest wall, and even might challenge molecular imaging techniques in the near future.

CONCLUSION

This article helps new users to implement appropriate protocols on their own MRI platforms. Main Messages • MRI of the lung can be readily performed on state-of-the-art 1.5-T MRI scanners. • Protocol suggestions based on the available literature facilitate its use for routine • MRI offers solutions for complicated thoracic masses with atelectasis and chest wall invasion. • MRI is an option for paediatrics and science when CT is contra-indicated.

Fatalities in wild goats in Kurdistan associated with Peste des Petits Ruminants virus

Between August 2010 and February 2011, over 750 deaths were recorded among wild goats (Capra aegagrus, the endangered progenitor of the domestic goat) in Kurdistan. Based on the clinical signs and post-mortem findings, the involvement of peste des petits ruminants virus (PPRV) was suspected. This was confirmed by laboratory analysis, and the virus was found to be closely related to a Turkish strain isolated in 2000. During the outbreak in wild goats, no disease in domestic animals was reported. Domestic ruminants in the region are routinely vaccinated with an attenuated vaccine based on the 'Nigeria/75/1' strain of PPRV. This is the first report of active PPRV infection in Kurdistan and most likely the immunity afforded by vaccination prevented spillover infections. It is therefore recommended to continue with the campaign. Conversely, there is no justification for the use of force to keep the endangered wild goats away from domestic flocks.

Right ventricular involvement in patients with Fabry's disease and the effect of enzyme replacement therapy

PURPOSE

According to echocardiography reports, Fabry cardiomyopathy not only affects the left ventricle (LV) but also the right ventricle (RV). Until now no MRI studies about the effect of enzyme replacement therapy (ERT) on the RV are available. We evaluated the effect of ERT on the RV.

MATERIALS AND METHODS

In this prospective trial 14 patients with genetically proven Fabry's disease were examined using a 1.5 T MR scanner before ERT and after 13 ± 1 months of ERT. All patients underwent cardiac MR imaging and the RV/LV cardiac morphology and function were analyzed.

RESULTS

At baseline examination the values were as follows: RV mass 31 ± 6 g/m (2), end-diastolic volume (EDV) 88 ± 13 ml/m (2), end-systolic volume (ESV) 39 ± 9 ml/m (2), stroke volume (SV) 49 ± 7 ml/m (2) and ejection fraction (EF) 56 ± 5 %. The RV mass and EDV decreased significantly after 13 ± 1 months on ERT (mass 27 ± 7 g/m (2), p < 0.05, EDV 76 ± 24 ml/m (2), p < 0.05), with no significant change of ESV (33 ± 13 ml/m (2)), SV (43 ± 12 ml/m (2)) and EF (57 ± 7 %). The LV mass (102 ± 26 g/m (2) vs. 94 ± 27 g/m (2), p < 0.05), EDV (76 ± 13 ml/m (2) vs. 66 ± 22 ml/m (2), p < 0.05) and ESV (29 ± 9 ml/m (2) vs. 23 ± 9 ml/m (2), p < 0.05) decreased significantly while the EF (64 ± 7 % vs. 66 ± 5 %; p < 0.05) increased significantly.

CONCLUSION

Besides the known beneficial effect on the LV, ERT improves RV mass and EDV.

Quantitative myocardial perfusion imaging with a MR cold pressor test

The response of myocardial blood flow to sympathetic stimulation with cold is modulated by endothelium-related factors. As endothelial dysfunction is an early step in patients with coronary artery disease, the aim of this study was to establish a cold pressor test (CPT) setting for quantitative analysis of myocardial perfusion in a MR scanner. First pass perfusion studies were performed in 10 healthy volunteers using a 1.5 T MR scanner with a multislice steady state free precession perfusion trueFISP sequence in prebolus technique (1 cc/4 cc gadobenate dimeglumine). MR-CPT was established using an over head ice-water bath of the left hand. First pass perfusion imaging was started after 1 min to assure an adequate stimulus followed by a second series after 15 min to evaluate the rest perfusion. After motion correction images were segmented with an adapted, automated tool, myocardial contours were determined. Perfusion was quantitatively evaluated after contamination and baseline correction by deconvolution with the arterial input function using an exponential function model as residuum. All data could be evaluated. Mean myocardial perfusion rose from 0.61 ± 0.22 cc/g/min at rest to 1.15 ± 0.34 cc/g/min under CPT. MR myocardial perfusion values show a comparable increase under CPT as published positron emission tomography data. Consequently, CPT for the presence of endothelial dysfunction is feasible in the MR environment.