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ABSTRACT Laboratory diagnosis of orthohantavirus infection is primarily based on serology. However, for a confirmed serological diagnosis, evaluation of a follow-up serum sample is essential, which is time consuming and causes delay. Real-time reverse transcription polymerase chain reaction (RT-PCR) tests, if positive, provide an immediate and definitive diagnosis, and accurately identify the causative agent, where the discriminative nature of serology is suboptimal. We re-evaluated sera from orthohantavirus-suspected clinical cases in the Dutch regions of Twente and Achterhoek from July 2014 to April 2016 for the presence of Puumala orthohantavirus (PUUV), Tula orthohantavirus (TULV), and Seoul orthohantavirus (SEOV) RNA. PUUV RNA was detected in 11% of the total number (n = 85) of sera tested, in 50% of sera positive for anti-PUUV/TULV IgM (n = 16), and in 1.4% of sera negative or indeterminate for anti-PUUV/TULV IgM (n = 69). No evidence was found for the presence of TULV or SEOV viral RNA. Based on these findings, we propose two algorithms to implement real-time RT-PCR testing in routine orthohantavirus diagnostics, which optimally provide clinicians with early confirmed diagnoses and could prevent possible further invasive testing and treatment.IMPORTANCEThe addition of a real-time reverse transcription polymerase chain reaction test to routine orthohantavirus diagnostics may better aid clinical decision making than the use of standard serology tests alone. Awareness by clinicians and clinical microbiologists of this advantage may ultimately lead to a reduction in over-hospitalization and unnecessary invasive diagnostic procedures.

We detected a highly divergent SARS-CoV-2 Alpha variant in an immunocompromised person several months after the latest detection of the Alpha variant in the Netherlands. The patient was infected for 42 weeks despite several treatment regimens and disappearance of most clinical symptoms. We identified several potential immune escape mutations in the spike protein.

Abstract Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when

Rapid detection of infection is essential for stopping the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The Roche SD Biosensor rapid antigen test for SARS-CoV-2 was evaluated in a nonhospitalized symptomatic population. We rapid-tested a sample onsite and compared results with those from reverse transcription PCR and virus culture. We analyzed date of onset and symptoms using data from a clinical questionnaire. Overall test sensitivity was 84.9% (95% CI 79.1–89.4) and specificity was 99.5% (95% CI 98.7–99.8). Sensitivity increased to 95.8% (95% CI 90.5–98.2) for persons who sought care within 7 days of symptom onset. Test band intensity and time to result correlated strongly with viral load; thus, strong positive results could be read before the recommended time. Approximately 98% of all viable specimens with cycle threshold

There are currently no drugs available to treat SARS-CoV-2 infection. A promising alternative treatment for COVID-19 patients is convalescent plasma. Here, Gharbharan et al. collect covalescent plasma and report no overall clinical benefit for 86 patients hospitalized for COVID-19 and treated with 300 mL convalescent plasma.

Duration of infectious SARS-CoV-2 shedding is an important measure for improved disease control. Here, the authors use virus cultures of respiratory tract samples from COVID-19 patients and observe a median shedding duration of 8 days and a drop below 5% after 15,2 days post onset of symptoms.

Identifying the origin of the rabies virus (RABV) infection may have significant implications for control measures. Here, we identified the source of a RABV infection of two Nepalese migrants in Qatar by comparing their RABV genomes with RABV genomes isolated from the brains of a RABV infected camel and fox from Qatar.

During a meeting in Munich, Germany, a presymptomatic attendee with severe acute respiratory syndrome coronavirus 2 infected at least 11 of 13 other participants. Although 5 participants had no or mild symptoms, 6 had typical coronavirus disease, without dyspnea. Our findings suggest hand shaking and face-to-face contact as possible modes of transmission.

BackgroundPerformance of the SD Biosensor saliva antigen rapid test was evaluated at a large designated testing site in non-hospitalized patients, with or without symptoms.MethodAll eligible people over 18 years of age presenting for a booked appointment at the designated SARS-CoV-2 testing site were approached for inclusion and enrolled following verbal informed consent. One nasopharyngeal swab was taken to carry out the default antigen rapid test from which the results were reported back to the patient and one saliva sample was self-taken according to verbal instruction on site. This was used for the saliva antigen rapid test, the RT-PCR and for virus culture. Sensitivity of the saliva antigen rapid test was analyzed in two ways: i, compared to saliva RT-PCR; and ii, compared to virus culture of the saliva samples. Study participants were also asked to fill in a short questionnaire stating age, sex, date of symptom onset. Recommended time of ≥30mins since last meal, drink or cigarette if applicable was also recorded. The study was carried out in February-March 2021 for 4 weeks.ResultsWe could include 789 people with complete records and results. Compared to saliva RT-PCR, overall sensitivity and specificity of the saliva antigen rapid test was 66.1% and 99.6% which increased to 88.6% with Ct ≤30 cutoff. Analysis by days post onset did not result in higher sensitivities because the large majority of people were in the very early phase of disease ie ConclusionOverall, the potential benefits of saliva antigen rapid test, could outweigh the lower sensitivity compared to nasopharyngeal antigen rapid test in a comprehensive testing strategy, especially for home/self-testing and in vulnerable populations like elderly, disabled or children where in intrusive testing is either not possible or causes unnecessary stress.

ABSTRACT Since its emergence in the United States in 2014, enterovirus D68 (EV-D68) has been and is associated with severe respiratory diseases and acute flaccid myelitis. Even though EV-D68 has been shown to replicate in different neuronal cells in vitro, it is currently poorly understood which viral factors contribute to the ability to replicate efficiently in cells of the central nervous system and whether this feature is a clade-specific feature. Here, we determined the replication kinetics of clinical EV-D68 isolates from (sub)clades A, B1, B2, B3, and D1 in human neuroblastoma cells (SK-N-SH). Subsequently, we compared sequences to identify viral factors associated with increased viral replication. All clinical isolates replicated in SK-N-SH cells, although there was a large difference in efficiency. Efficient replication of clinical isolates was associated with an amino acid substitution at position 271 of VP1 (E271K), which was acquired during virus propagation in vitro. Recognition of heparan sulfate in addition to sialic acids was associated with increased attachment, infection, and replication. Removal of heparan sulfate resulted in a decrease in attachment, internalization, and replication of viruses with E271K. Taken together, our study suggests that the replication kinetics of EV-D68 isolates in SK-N-SH cells is not a clade-specific feature. However, recognition of heparan sulfate as an additional receptor had a large effect on phenotypic characteristics in vitro. These observations emphasize the need to compare sequences from virus stocks with clinical isolates in order to retrieve phenotypic characteristics from original virus isolates. IMPORTANCE Enterovirus D68 (EV-D68) causes mild to severe respiratory disease and is associated with acute flaccid myelitis since 2014. Currently, the understanding of the ability of EV-D68 to replicate in the central nervous system (CNS), and whether it is associated with a specific clade of EV-D68 viruses or specific viral factors, is lacking. Comparing different EV-D68 clades did not reveal clade-specific phenotypic characteristics. However, we did show that viruses which acquired a cell culture-adapted amino acid substitution in VP1 (E271K) recognized heparan sulfate as an additional receptor. Recognition of heparan sulfate resulted in an increase in attachment, infection, and replication in neuroblastoma cells compared with viruses without this specific amino acid substitution. The ability of EV-D68 viruses to acquire cell culture-adaptive substitutions which have a large effect in experimental settings emphasizes the need to sequence virus stocks.

We evaluated the benefit of whole blood versus plasma to detect acute Zika virus infections. Comparison of Zika virus quantitative reverse transcription PCR results in single timepoint whole blood–plasma pairs from 227 patients with suspected Zika virus infection resulted in confirmation of 8 additional patients with Zika virus infection.

Inducible Bronchus Associated Lymphoid Tissue (iBALT) is a long lasting tertiary lymphoid tissue that can be induced following influenza A virus (IAV) infection. Previous studies have shown that iBALT structures containing germinal center (GC) B cells protect against repeated infection by contributing locally to the cellular and humoral immune response. If we are to exploit this in vaccination strategies, we need a better understanding on how iBALT structures are induced. One hypothesis is that the strength of the initial innate response dictates induction of iBALT. In the present study, we investigated the role of IL-1 and IL-1R signalling on iBALT formation.Mice lacking the IL-1R, had a delayed viral clearance and thus a prolonged exposure to viral replication, leading to increased disease severity compared to wild type mice. Contradictorily, iBALT formation following clearance of the virus was heavily compromised in Il1r1-/- mice. Quantification of gene induction after IAV infection demonstrated induction of IL-1α and to a much lesser extent of IL-1β. Administration of recombinant IL-1α to the lungs of wild type mice early and late after IAV infection, led to more pronounced iBALT formation and an increased amount of GC B cells in the lungs. Bone marrow chimeric mice identified the stromal compartment as the crucial IL-1 responsive cell for iBALT induction. Mechanistically, Q-PCR analysis of lung homogenates revealed a strongly diminished production of CXCL13, a B cell attracting chemokine, in Il1r-/- mice during the early innate phase of IAV infection. These experiments demonstrate that appropriate innate IL 1α - IL 1R signalling is necessary for IAV clearance and at the same time instructs the formation of organized tertiary lymphoid tissues through induction of CXCL13 early after infection. These findings are discussed in the light of recent insights on the pathogenesis of TLO formation in the lung in various diseases where the IL-1 axis is hyperactive such as rheumatoid arthritis and COPD.