Effect of autolysis on the specificity of bovine spongiform encephalopathy rapid tests

<p>Abstract</p> <p>Background</p> <p>Routine rapid testing for Bovine Spongiform Encephalopathy (BSE) has highlighted some problems with BSE rapid test performance, the most significant being the number of initially reactive samples and the false positive results on autolyzed tissue. This point is important for BSE active surveillance in risk populations, because tissue autolysis is often unavoidable in routine cases. A robust test suitable for use on field material is therefore needed. To date, very limited information regarding the effect of autolysis on the robustness of rapid tests has been documented; therefore, the National Reference Centre for Animal Encephalopathies (CEA) rapid test laboratory selected 450 autolyzed and negative brain stem samples from fallen stock bovines older than 24 months to assess the specificity of four tests approved for BSE active surveillance: Biorad TeSeE, Enfer TSE version 2.0, Prionics^®Check LIA, and IDEXX Herd Check BSE Antigen Kit EIA. The samples were graded according to the degree of autolysis and then dissected into five portions, four of which randomly assigned to processing by rapid tests and one to be available for confirmatory Western blot analysis.</p> <p>Findings</p> <p>The specificity of the four systems was 100% for all three grades of autolysis, while the percentage of initially reactive results was 0.00 (95%CI 0.00-0.82), 0.22 (95%CI 0.006-1.23), 0.44 (95%CI 0.05-1.60), and 0.89 (95%CI 0.24-2.26) for the Biorad TeSeE, the Prionics^®Check LIA, the IDEXX Herd Check BSE and the Enfer TSE tests, respectively. No association with the degree of autolysis could be drawn.</p> <p>Conclusions</p> <p>The present study demonstrates that the four rapid tests can be considered well-running diagnostic tools regardless of tissue quality; nevertheless, the number of initial reactive samples reported for some systems must not be underestimated in routine testing.</p> <p>Furthermore the compliance with the reported performance can be guaranteed only when an ongoing high careful batch quality control system is in place.</p

Are rapid tests and confirmatory western blot used for cattle and small ruminants TSEs reliable tools for the diagnosis of Chronic Wasting Disease in Europe?

The first case of CWD in Europe was detected in a Norwegian reindeer in 2016, followed later by two CWD cases in Norwegian moose. To prevent the potential spread of CWD to the EU, the European Commission (Regulation EU 2017_1972) implemented a CWD surveillance programme in cervids in the six countries having reindeer and or moose (Estonia, Finland, Latvia, Lithuania, Poland, and Sweden). Each country had to test a minimum of 3000 cervids for CWD using diagnostic rapid tests approved by the EC Regulation. Experimental transmission studies in rodents have demonstrated that the CWD strains found in Norwegian reindeer are different from those found in moose and that these European strains are all different from the North American ones. Data on the performances of authorised rapid tests are limited for CWD (from North America) and are currently minimal for CWD from Europe, due to the paucity of positive material. The aim of this study was to evaluate the diagnostic performances of three of the so-called “rapid” tests, commercially available and approved for TSE diagnosis in cattle and small ruminants, to detect the CWD strains circulating in Europe. The performances of these three tests were also compared to two different confirmatory western blot methods. Using parallel testing on the same panel of available samples, we evaluated here the analytical sensitivity of these methods for TSE diagnosis of CWD in Norwegian cervids tissues. Our results show that all the methods applied were able to detect the CWD positive samples even if differences in analytical sensitivity were clearly observed. Although this study could not assess the test accuracy, due to the small number of samples available, it is conceivable that the rapid and confirmatory diagnostic systems applied for CWD surveillance in Northern Europe are reliable tools

Cardiovascular disease as part of Long COVID: A systematic review

Aims: Long COVID syndrome has had a major impact on million patients’ lives worldwide. The cardiovascular system is an important aspect of this multifaceted disease that may manifest in many ways. We have hereby performed a narrative review in order to identify the extent of the cardiovascular manifestations of the Long COVID syndrome. Methods and results: An in-depth systematic search of the literature has been conducted for this narrative review. The systematic search of PubMed and Cochrane databases yielded 3993 articles, of which 629 underwent full-text screening. A total of 78 studies were included in the final qualitative synthesis and data evaluation. The pathophysiology of the cardiovascular sequelae of Long COVID syndrome and the cardiac manifestations and complications of Long COVID syndrome are critically evaluated. In addition, potential cardiovascular risk factors are assessed, and preventive methods and treatment options are examined in this review. Conclusion: This systematic review poignantly summarizes the evidence from the available literature regarding the cardiovascular manifestations of Long COVID syndrome and reviews potential mechanistic pathways, diagnostic approaches, preventive measures, and treatment options

Rapid tests might overlook bovine spongiform encephalopathy infection in goats

International audienc

Transmissible Spongiform Encephalopathies rapid post mortem tests in goats: Strategies to improve the efficiency of the active surveillance statutory programme

International audienc