Healthy donors exposed to Japanese encephalitis (JE) virus show a CD8+ T cell response that cross reacts with other flaviviruses. Patients that recovered from JE show a CD4+ T cell response that targets structural proteins of JE virus.
We have carried out an antigenic analysis and nucleotide sequence comparison of the envelope glycoprotein of recognized louping ill virus strains isolated from Scotland with that of a Norwegian virus known to cause encephalomyelitis in sheep. Monoclonal antibodies with defined specificity for the louping ill virus envelope glycoprotein failed to distinguish between the Norwegian virus and prototype louping ill virus in indirect immunofluorescence, haemagglutination inhibition and neutralization tests. Nucleotide sequencing of the envelope glycoprotein and alignment of the deduced amino acid sequence with other known sequences revealed that the Norwegian virus closely resembles (> 95 % identity for nucleotide and > 98% identity for amino acid sequences) louping ill virus. Maximum variation in identities among four strains of louping ill virus were 4-4 % and 1.8 % respectively for nucleotide and amino acid alignments. We conclude that sheep encephalomyelitis in Norway is caused by louping ill virus. These results imply that other viruses present in Europe and known to cause encephalitis/encephalomyelitis of sheep could be caused by louping ill virus.Louping ill (LI) virus is a tick-borne member of the genus Flavivirus in the family Flaviviridae and is closely related antigenically to other members of the tick-borne encephalitis (TBE) flavivirus serocomplex (Porterfield, 1980;Westaway et al., 1985;Francki et al., 1991). There are currently about 68 antigenically distinct, but very closely related viruses in the genus, many of which cause serious human and animal diseases. Flaviviruses contain a positive-stranded RNA genome approximately 10.5 kb in length and with a similar organization. Complete or partial nucleotide sequences of many flaviviruses have been determined (Rice et al
Objective: To perform a systematic review and meta-analysis to compare the diagnostic accuracy of CT and initial reverse transcriptase polymerase chain reaction (RT-PCR) for detecting COVID-19 infection. Methods: We searched three databases, PubMed, EMBASE, and EMCARE, to identify studies reporting diagnostic accuracy of both CT and RT-PCR in detecting COVID-19 infection between December 2019 and May 2020. For accurate comparison, only those studies that had patients undergoing both CT and RT-PCR were included. Pooled diagnostic accuracy of both the tests was calculated by using a bivariate random effects model. Results: Based on inclusion criteria, only 11 studies consisting of 1834 patients were included in the final analysis that reported diagnostic accuracy of both CT and RT-PCR, in the same set of patients. Sensitivity estimates for CT scan ranged from 0.69 to 1.00 and for RT-PCR varied ranging from 0.47 to 1.00. The pooled estimates of sensitivity for CT and RT-PCR were 0.91 [95% CI (0.84–0.97)] and 0.84 [95% CI (0.71–0.94)], respectively. On subgroup analysis, pooled sensitivity of CT and RT-PCR was 0.95 [95% CI (0.88–0.98)] and 0.91 [95% CI (0.80–0.96), p = o.ooo1]. The pooled specificity of CT and RT-PCR was 0.31 [95% CI (0.035–0.84)] and 1.00 [95% CI (0.96–1.00)]. Conclusion: CT is more sensitive than RT-PCR in detecting COVID-19 infection, but has a very low specificity. Advances in knowledge: Since the results of a CT scan are available quickly, it can be used as an adjunctive initial diagnostic test for patients with a history of positive contact or epidemiological history.
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