Metapneumovirus: determinants of host range and replication

The general composition of the metapneumovirus genome is similar to that of pneumoviruses but differs in the number of genes and their order in the genome (Figure 2) (237). Metapneumoviruses do not encode the nonstructural proteins NS1 and NS2, and the small hydrophobic (SH) and attachment (G) protein genes follow the fusion (F), M2.1 and M2.2 protein genes, whereas for pneumoviruses this is the other way around. In evolutionary terms, this difference is very striking since recombination for members of the subfamily Pneumovirinae has been observed in a laboratory setting only (218). The 3’ and 5’ ends of the genome consist of short extragenic regions, referred to as the leader and trailer regions, and approximately the terminal 12 nt of the leader and the terminal 12 nt of the trailer are complementary, most likely due to the fact that each contains the basic elements of the viral promoter (21, 57, 163). The 3’ end of the viral RNA (vRNA) directs both replication and transcription, while the 5’ end of the genome contains signals that direct the replication of the antigenome. Each gene is preceded by a gene start (GS) signal at which the synthesis of mRNA initiates. Subsequently, each gene terminates with a semiconserved gene end (GE) signal that directs polyadenylation and termination of the completed mRNA. The genomes of metapneumoviruses consist of non-segmented negative stranded RNA and are smaller (~13.000 kb) than those of pneumoviruses (~15.000 kb) (70). For members of the subfamily Paramyxovirinae, the nucleotide length of each genome is a multiplicity of six (“rule of six”), reflecting a requirement of the nucleocapsid for RNA binding (e.g., binding units of six nucleotides) (34). This rule does not apply for the subfamily Pneumovirinae (201), although the reasons underlying this discrepancy have not been determined

Effect of oral infection with Kashmir bee virus and Israeli acute paralysis virus on bumblebee (Bombus terrestris) reproductive success

Israeli acute paralysis virus (IAPV) together with Acute bee paralysis virus (ABPV) and Kashmir bee virus (KBV) constitute a complex of closely related dicistroviruses. They are infamous for their high mortality after injection in honeybees. These viruses have also been reported in non-Apis hymenopteran pollinators such as bumblebees, which got infected with IAPV when placed in the same greenhouse with IAPV infected honeybee hives. Here we orally infected Bombus terrestris workers with different doses of either IAPV or KBV viral particles. The success of the infection was established by analysis of the bumblebees after the impact studies: 50 days after infection. Doses of 0.5 x 10(7) and 1 x 10(7) virus particles per bee were infectious over this period, for IAPV and KBV respectively, while a dose of 0.5 x 10(6) IAPV particles per bee was not infectious. The impact of virus infection was studied in micro-colonies consisting of 5 bumblebees, one of which becomes a pseudo-queen which proceeds to lay unfertilized (drone) eggs. The impact parameters studied were: the establishment of a laying pseudo-queen, the timing of egg-laying, the number of drones produced, the weight of these drones and worker mortality. In this setup KBV infection resulted in a significant slower colony startup and offspring production, while only the latter can be reported for IAPV. Neither virus increased worker mortality, at the oral doses used. We recommend further studies on how these viruses transmit between different pollinator species. It is also vital to understand how viral prevalence can affect wild bee populations because disturbance of the natural host-virus association may deteriorate the already critically endangered status of many bumblebee species

Does the outcome of diagnostic ultrasound influence the treatment modalities and recovery in patients with shoulder pain in physiotherapy practice? Results from a prospective cohort study

© 2019 Elsevier Ltd Study design: Prospective cohort study including patients with shoulder pain in primary care physiotherapy. Background: There is an increased tendency to use diagnostic ultrasound to aid the diagnostic strategy and target treatment. It is a relatively cheap and accessible imaging technique but the implications for practice and patients are unknown. Objectives: To study the influence of diagnostic ultrasound (DUS) on diagnostic work-up, treatment modalities and recovery. Methods: Participants (n = 389) with a new episode of shoulder pain were assessed at baseline and followed for 6, 12 and 26 weeks. Diagnostic work-up, including the use of DUS, and treatment strategies were reported by the therapists at 3, 6 and 12 weeks. Results: Most patients (41%) were diagnosed with subacromial impingement/pain syndrome after physical examination or DUS. DUS was used in 31% of the participants. Tendinopathy was the most found abnormality in this sub-population. Patients who underwent DUS were more frequently treated using exercise therapy. Patients that not had DUS were more likely to receive massage therapy, trigger point therapy or mobilisation techniques. Logistic regression analyses did not show a significant association between DUS and recovery after 26 weeks (0.88, 95%CI:0.50–1.57). Correcting for the therapist as a confounder using a multilevel binary logistic regression did not show a significant cluster effect. Conclusion: Diagnostic US as a work-up component does not seem to influence diagnosis or recovery but does influence the choice of treatment modality. Conclusions are limited to observational data. High quality randomized trials should study the effect of DUS on recovery

Capturing norovirus transmission

Human norovirus is a leading cause of gastroenteritis and is efficiently transmitted between humans and around the globe. The burden of norovirus infections in the global community and in health-care settings warrant the availability of outbreak prevention strategies and control measures that are tailored to the pathogen, outbreak setting and population at risk. A better understanding of viral and host determinants of transmission would aid in developing and fine-tuning such efforts. Here, we describe mechanisms of transmission, available model systems for studying norovirus transmission and their strengths and weaknesses as well as future research strategies

Cold case: The disappearance of Egypt bee virus, a fourth distinct master strain of deformed wing virus linked to honeybee mortality in 1970’s Egypt

In 1977, a sample of diseased adult honeybees (Apis mellifera) from Egypt was found to contain large amounts of a previously unknown virus, Egypt bee virus, which was subsequently shown to be serologically related to deformed wing virus (DWV). By sequencing the original isolate, we demonstrate that Egypt bee virus is in fact a fourth unique, major variant of DWV (DWV-D): more closely related to DWV-C than to either DWV-A or DWV-B. DWV-A and DWV-B are the most common DWV variants worldwide due to their close relationship and transmission by Varroa destructor. However, we could not find any trace of DWV-D in several hundred RNA sequencing libraries from a worldwide selection of honeybee, varroa and bumblebee samples. This means that DWV-D has either become extinct, been replaced by other DWV variants better adapted to varroa-mediated transmission, or persists only in a narrow geographic or host range, isolated from common bee and beekeeping trade routes

Molecular epidemiology of seal parvovirus, 1988-2014

A novel parvovirus was discovered recently in the brain of a harbor seal (Phoca vitulina) with chronic meningo-encephalitis. Phylogenetic analysis of this virus indicated that it belongs to the genus Er

Lumbar spine segmentation in MR images: a dataset and a public benchmark

This paper presents a large publicly available multi-center lumbar spine magnetic resonance imaging (MRI) dataset with reference segmentations of vertebrae, intervertebral discs (IVDs), and spinal canal. The dataset includes 447 sagittal T1 and T2 MRI series from 218 patients with a history of low back pain. It was collected from four different hospitals and was divided into a training (179 patients) and validation (39 patients) set. An iterative data annotation approach was used by training a segmentation algorithm on a small part of the dataset, enabling semi-automatic segmentation of the remaining images. The algorithm provided an initial segmentation, which was subsequently reviewed, manually corrected, and added to the training data. We provide reference performance values for this baseline algorithm and nnU-Net, which performed comparably. We set up a continuous segmentation challenge to allow for a fair comparison of different segmentation algorithms. This study may encourage wider collaboration in the field of spine segmentation, and improve the diagnostic value of lumbar spine MRI

Population-based screening in a municipality after a primary school outbreak of the SARSCoV-2 Alpha variant, the Netherlands, December 2020–February 2021

An outbreak of SARS-CoV-2 Alpha variant (Pango lineage B.1.1.7) was detected at a primary school (School X) in Lansingerland, the Netherlands, in December 2020. The outbreak was studied retrospectively, and population-based screening was used to assess the extent of virus circulation and decelerate transmission. Cases were SARS-CoV-2 laboratory confirmed and were residents of Lansingerland (November 16(th) 2020 until February 22(th) 2021), or had an epidemiological link with School X or neighbouring schools. The SARS-CoV-2 variant was determined using variant PCR or whole genome sequencing. A questionnaire primarily assessed clinical symptoms. A total of 77 Alpha variant cases were found with an epidemiological link to School X, 16 Alpha variant cases linked to the neighbouring schools, and 146 Alpha variant cases among residents of Lansingerland without a link to the schools. The mean number of self-reported symptoms was not significantly different among Alpha variant infected individuals compared to non-Alpha infected individuals. The secondary attack rate (SAR) among Alpha variant exposed individuals in households was 52% higher compared to non-Alpha variant exposed individuals (p = 0.010), with the mean household age, and mean number of children and adults per household as confounders. Sequence analysis of 60 Alpha variant sequences obtained from cases confirmed virus transmission between School X and neighbouring schools, and showed that multiple introductions of the Alpha variant had already taken place in Lansingerland at the time of the study. The alpha variant caused a large outbreak at both locations of School X, and subsequently spread to neighbouring schools, and households. Population-based screening (together with other public health measures) nearly stopped transmission of the outbreak strain, but did not prevent variant replacement in the Lansingerland municipality

Real-time reverse transcriptase PCR assay for detection of human metapneumoviruses from all known genetic lineages

The discovery of human metapneumovirus and its implications for respiratory tract disease have emphasized the need for a sensitive, specific, and rapid assay to detect this virus in a clinical setting. It recently became clear that human metapneumovirus can be grouped into at least four genetic lineages. Previously described assays for the detection of human metapneumovirus were developed by using limited sequence information and failed to detect viruses from all four genetic lineages with comparable sensitivities. Here we describe the development and evaluation of a real-time reverse transcriptase PCR assay that detects human metapneumovirus from the four known genetic lineages with equal specificities and sensitivities

Virus Prevalence in Egg Samples Collected from Naturally Selected and Traditionally Managed Honey Bee Colonies across Europe

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the 'suppressed in ovo virus infection' trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time