Case Series of Jamestown Canyon Virus Infections with Neurologic Outcomes, Canada, 2011-2016.

Jamestown Canyon virus (JCV) is a mosquitoborne orthobunyavirus in the California serogroup that circulates throughout Canada and the United States. Most JCV exposures result in asymptomatic infection or a mild febrile illness, but JCV can also cause neurologic diseases, such as meningitis and encephalitis. We describe a case series of confirmed JCV-mediated neuroinvasive disease among persons from the provinces of British Columbia, Alberta, Quebec, and Nova Scotia, Canada, during 2011-2016. We highlight the case definitions, epidemiology, unique features and clinical manifestations, disease seasonality, and outcomes for those cases. Two of the patients (from Quebec and Nova Scotia) might have acquired JCV infections during travel to the northeastern region of the United States. This case series collectively demonstrates JCV's wide distribution and indicates the need for increased awareness of JCV as the underlying cause of meningitis/meningoencephalitis during mosquito season.

Widespread Exposure to Mosquitoborne California Serogroup Viruses in Caribou, Arctic Fox, Red Fox, and Polar Bears, Canada.

Northern Canada is warming at 3 times the global rate. Thus, changing diversity and distribution of vectors and pathogens is an increasing health concern. California serogroup (CSG) viruses are mosquitoborne arboviruses; wildlife reservoirs in northern ecosystems have not been identified. We detected CSG virus antibodies in 63% (95% CI 58%-67%) of caribou (n = 517), 4% (95% CI 2%-7%) of Arctic foxes (n = 297), 12% (95% CI 6%-21%) of red foxes (n = 77), and 28% (95% CI 24%-33%) of polar bears (n = 377). Sex, age, and summer temperatures were positively associated with polar bear exposure; location, year, and ecotype were associated with caribou exposure. Exposure was highest in boreal caribou and increased from baseline in polar bears after warmer summers. CSG virus exposure of wildlife is linked to climate change in northern Canada and sustained surveillance could be used to measure human health risks.

Role of Anopheles Mosquitoes in Cache Valley Virus Lineage Displacement, New York, USA.

Cache Valley virus (CVV) is a mosquitoborne virus that infects livestock and humans. We report results of surveillance for CVV in New York, USA, during 2000-2016; full-genome analysis of selected CVV isolates from sheep, horse, humans, and mosquitoes from New York and Canada; and phenotypic characterization of selected strains. We calculated infection rates by using the maximum-likelihood estimation method by year, region, month, and mosquito species. The highest maximum-likelihood estimations were for Anopheles spp. mosquitoes. Our phylogenetic analysis identified 2 lineages and found evidence of segment reassortment. Furthermore, our data suggest displacement of CVV lineage 1 by lineage 2 in New York and Canada. Finally, we showed increased vector competence of An. quadrimaculatus mosquitoes for lineage 2 strains of CVV compared with lineage 1 strains.

Hantavirus Cardiopulmonary Syndrome in Canada.

Hantavirus cardiopulmonary syndrome (HCPS) is a severe respiratory disease caused by Sin Nombre virus in North America (SNV). As of January 1, 2020, SNV has caused 143 laboratory-confirmed cases of HCPS in Canada. We review critical aspects of SNV virus epidemiology and the ecology, biology, and genetics of HCPS in Canada.

Taxonomy of the order Bunyavirales: update 2019.

In February 2019, following the annual taxon ratification vote, the order Bunyavirales was amended by creation of two new families, four new subfamilies, 11 new genera and 77 new species, merging of two species, and deletion of one species. This article presents the updated taxonomy of the order Bunyavirales now accepted by the International Committee on Taxonomy of Viruses (ICTV).

Seroprevalence of Cache Valley virus and related viruses in sheep and other livestock from Saskatchewan, Canada.

Cache Valley virus, an orthobunyavirus, is an important cause of ovine neonatal malformations. Information on the seroprevalence of this virus in Saskatchewan livestock populations is lacking. The objectives of this study were to determine the seroprevalence of Cache Valley virus and closely related viruses in sheep, cattle, goats, horses, and mule deer in Saskatchewan by performing a plaque-reduction neutralization test using Cache Valley virus. In total, sera from 130 sheep from 50 flocks were tested. Seroprevalence in sheep was 64.6% (84/130) and 94.0% (47/50) of flocks had 1 or more seropositive sheep. Antibodies to Cache Valley virus or closely related viruses were also detected in serum samples collected from cattle, goats, horses, and mule deer with seroprevalences of 20.0% (5/25), 33.3% (8/24), 69.0% (40/58), and 50.8% (33/65), respectively. These results suggest widespread exposure to Cache Valley virus or closely related viruses in domestic animals and mule deer in Saskatchewan.

Séroprevalence du virus de la Vallée Cache ou de virus connexes chez les moutons et d'autres animaux de cheptel en Saskatchewan, Canada. Le virus de la Vallée Cache, un orthobunyavirus, est une cause importante de malformations néonatales ovines. Il manque des renseignements sur la séroprévalence de ce virus dans les populations des cheptels de la Saskatchewan. Les objectifs de cette étude consistaient à déterminer la séroprévalence du virus de la Vallée Cache et des virus étroitement apparentés chez les moutons, les bovins, les chèvres, les chevaux et les cerfs mulets en Saskatchewan en réalisant un test de séro-neutralisation par réduction des plages en utilisant le virus de la Vallée Cache. Au total, le sérum provenant de 130 moutons dans 50 troupeaux a été testé. Chez les moutons, la séroprévalence était de 64,6 % (84/130) et 94,0 % (47/50) des troupeaux avaient un mouton ou plusieurs moutons séropositifs. Les anticorps pour le virus de la Vallée Cache ou les virus étroitement apparentés ont aussi été détectés dans les échantillons de sérum prélevés auprès des bovins, des chèvres, des chevaux et des cerfs mulets avec une séroprévalence de 20,0 % (5/25), de 33,3 % (8/24), de 69,0 % (40/58) et de 50,8 % (33/65), respectivement. Ces résultats suggèrent une vaste exposition au virus de la Vallée Cache ou à des virus étroitement apparentés chez les animaux domestiques et les cerfs mulets en Saskatchewan.(Traduit par Isabelle Vallières).

California Serogroup Virus Infection Associated with Encephalitis and Cognitive Decline, Canada, 2015.

California serogroup (CSG) viruses, such as Jamestown Canyon and snowshoe hare viruses, are mosquitoborne pathogens that cause febrile illness and neurologic disease. Human exposures have been described across Canada, but infections are likely underdiagnosed. We describe a case of neuroinvasive illness in a New Brunswick, Canada, patient infected with a CSG virus.

First Imported Case of Chikungunya Virus Infection in a Travelling Canadian Returning from the Caribbean.

This is the first Canadian case of Chikungunya virus (CHIKV) infection reported in a traveller returning from the Caribbean. Following multiple mosquito bites in Martinique Island in January 2014, the patient presented with high fever, headaches, arthralgia on both hands and feet, and a rash on the trunk upon his return to Canada. Initial serological testing for dengue virus infection was negative. Support therapy with nonsteroidal anti-inflammatory drugs was administered. The symptoms gradually improved 4 weeks after onset with residual arthralgia and morning joint stiffness. This clinical feature prompted the clinician to request CHIKV virus serology which was found to be positive for the presence of IgM and neutralizing antibodies. In 2014, over four hundred confirmed CHIKV infection cases were diagnosed in Canadian travellers returning from the Caribbean and Central America. Clinical suspicion of CHIKV or dengue virus infections should be considered in febrile patients with arthralgia returning from the recently CHIKV endemic countries of the Americas.

Zoonotic infections in communities of the James Bay Cree territory: An overview of seroprevalence.

The Cree communities of James Bay are at risk for contracting infectious diseases transmitted by wildlife. Data from serological testing for a range of zoonotic infections performed in the general population (six communities), or trappers and their spouses (one community), were abstracted from four population-based studies conducted in Cree territory (Quebec) between 2005 and 2009. Evidence of exposure to Trichinella species, Toxoplasma gondii, Toxocara canis, Echinococcus granulosus, Leptospira species, Coxiella burnetii and Francisella tularensis was verified in all communities, whereas antibodies against Sin Nombre virus and California serogroup viruses (Jamestown Canyon and snowshoe hare viruses) were evaluated in three and six communities, respectively. Seroprevalence varied widely among communities: snowshoe hare virus (1% to 42%), F tularensis (14% to 37%), Leptospira species (10% to 27%), Jamestown Canyon virus (9% to 24%), C burnetii (0% to 18%), T gondii (4% to 12%), T canis (0% to 10%), E granulosus (0% to 4%) and Trichinella species (0% to 1%). No subject had serological evidence of Sin Nombre virus exposure. These data suggest that large proportions of the Cree population have been exposed to at least one of the targeted zoonotic agents. The Cree population, particularly those most heavily exposed to fauna, as well as the medical staff living in these regions, should be aware of these diseases. Greater awareness would not only help to decrease exposures but would also increase the chance of appropriate diagnostic testing.

Les communautés cries de la Baie James sont vulnérables aux maladies infectieuses transmises par les animaux sauvages. Les données tirées des tests sérologiques sur une série de zoonoses effectués dans la population générale (six communautés) ou chez les trappeurs et leur conjointe (une communauté) ont été extraites de quatre études en population menées en territoire cri, au Québec, entre 2005 et 2009. Les manifestations d'exposition aux espèces de Trichinella, au Toxoplasma gondii, au Toxocara canis, à l'Echinococcus granulosus, aux espèces de Leptospira, au Coxiella burnetii et au Francisella tularensis ont été vérifiées dans toutes les communautés, tandis que les anticorps contre le virus Sin Nombre et les virus du sérogroupe Californie (virus Jamestown Canyon et snowshoe hare) ont été évalués dans trois et six communautés, respectivement. La séroprévalence variait considérablement selon les communautés, comme suit : virus snowshoe hare (1 % à 42 %), F tularensis (14 % à 37 %), espèces de Leptospira (10 % à 27 %), virus Jamestown Canyon (9 % à 24 %), C burnetii (0 % à 18 %), T gondii (4 % à 12 %), T canis (0 % à 10 %), E granulosus (0 % à 4 %) et espèces de Trichinella (0 % à 1 %). Aucun sujet n'avait de manifestation sérologique d'exposition au virus Sin Nombre. Ces données laissent supposer que de fortes proportions de la population crie ont été exposées à au moins l'un des agents zoonotiques ciblés. La population crie, notamment les peuples les plus exposés aux animaux sauvages, ainsi que le personnel médical qui habite dans ces régions, devrait connaître ces maladies. Une meilleure sensibilisation contribuerait non seulement à réduire les expositions, mais accroîtrait également la possibilité de tests diagnostiques pertinents.

Roles of host species, geographic separation, and isolation in the seroprevalence of Jamestown Canyon and snowshoe hare viruses in Newfoundland.

California serogroup viruses, including Jamestown Canyon virus (JCV) and snowshoe hare virus (SSHV), are mosquito-borne members of the Bunyaviridae family and are endemic across North America. These arboviruses are potential pathogens which occasionally cause neuroinvasive disease in humans and livestock. A neutralization assay was used to document JCV and SSHV seroprevalence using blood collected from a variety of domestic and wildlife host species. These species were sampled in an island setting, Newfoundland, which contains diverse ecoregions, ecological landscapes, and habitats. Seroprevalence rates for each virus differed significantly among host species and within certain species across different geographic areas. JCV was significantly associated with large mammals, and SSHV was significantly associated with snowshoe hares. Seroprevalence rates in the 5 species of animals tested for prior exposure to JCV ranged from 0% in snowshoe hares to 64% in horses. Seroprevalence rates for SSHV ranged from less than 1% in bovines to 55% in all snowshoe hares. The seroprevalence of SSHV differed significantly (P < 0.05) among hares occupying the discrete habitats of watersheds separated by 14 to 35 km. Cattle on farms in boreal forest landscapes displayed significantly higher JCV seroprevalence (P < 0.001) than those on farms located in seacoast landscapes. Lifelong geographic isolation of cattle to insular Newfoundland was associated with significantly lower JCV seroprevalence (P < 0.01) than that for cattle which had lived off-island.

Canadian blood suppliers: An expanding role in public health surveillance?

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic galvanized blood donor seroprevalence studies, which continue to inform public health policy. We propose that the two Canadian blood suppliers, Héma-Québec and Canadian Blood Services, expand their role in public health surveillance in the post-pandemic period. Together blood suppliers have near-national reach, collecting blood donations nearly every day in all larger cities and many smaller municipalities. Blood donors are a healthy subset of the general population. Demographic data, routine infectious disease testing and screening questionnaire data are collected for all donations. Close to one million blood samples per year could be made available for surveillance. With 90% repeat donors, longitudinal sampling is possible. Current blood donor surveillance includes monitoring infectious marker rates in low risk (e.g. HIV, hepatitis C virus) or asymptomatic (e.g. West Nile virus) populations, and ad hoc studies to monitor transfusion-transmissible infections. These include tick-borne infections such as Babesia microti and foodborne infections such as hepatitis E. Canadian Blood Services and Héma-Québec are actively seeking to engage with public health professionals to further develop a role in public health surveillance.

Evaluation of the performance of multiple immunoassay diagnostic platforms on the National Microbiology Laboratory SARS-CoV-2 National Serology Panel.

BACKGROUND: Serological assays designed to detect SARS-CoV-2 antibodies are being used in serological surveys and other specialized applications. As a result, and to ensure that the outcomes of serological testing meet high quality standards, evaluations are required to assess the performance of these assays and the proficiency of laboratories performing them. METHODS: A panel of 60 plasma/serum samples from blood donors who had reverse transcriptase-polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 infections and 21 SARS-CoV-2 negative samples were secured and distributed to interested laboratories within Canada (n = 30) and the United States (n = 1). Participating laboratories were asked to provide details on the diagnostic assays used, the platforms the assays were performed on, and the results obtained for each panel sample. Laboratories were blinded with respect to the expected outcomes. RESULTS: The performance of the different assays evaluated was excellent, with the high-throughput platforms of Roche, Ortho, and Siemens demonstrating 100% sensitivity. Most other high-throughput platforms had sensitivities of >93%, with the exception of the IgG assay using the Abbott ARCHITECT which had an average sensitivity of only 87%. The majority of the high-throughput platforms also demonstrated very good specificities (>97%). CONCLUSION: This proficiency study demonstrates that most of the SARS-CoV-2 serological assays utilized by provincial public health or hospital laboratories in Canada have acceptable sensitivity and excellent specificity.

HISTORIQUE: Les dosages sérologiques conçus pour dépister les anticorps anti-SRAS-CoV-2 sont utilisés dans les études sérologiques et d'autres applications spécialisées. Par conséquent, et pour s'assurer que leurs résultats respectent des normes de qualité, il faut procéder à des évaluations de leur performance et de la compétence des laboratoires à les effectuer. MÉTHODOLOGIE: Les chercheurs ont obtenu une batterie de 60 prélèvements de plasma et de sérum chez des donneurs dont l'amplification en chaîne par polymérase après transcription inverse (RT-PCR) avait confirmé des infections par le SRAS-CoV-2 et de 21 prélèvements dont les résultats étaient négatifs au SRAS-CoV-2 et les ont distribués aux laboratoires intéressés du Canada (n = 30) et des États-Unis (n = 1). Ils ont invité les laboratoires participants à fournir de l'information détaillée sur les dosages diagnostiques utilisés, les plateformes sur lesquelles les dosages étaient exécutés et les résultats obtenus pour chaque échantillon. Les chercheurs ont demandé aux laboratoires participants de fournir de l'information détaillée sur les dosages diagnostiques utilisés, les plateformes sur lesquelles les dosages ont été effectués, et les résultats obtenus à l'égard de chaque échantillon. Les laboratoires ont mené les études à l'insu des résultats escomptés. RÉSULTATS: Les divers dosages avaient une excellente exécution, les plateformes à haut débit de Roche, d'Ortho et de Siemens démontrant une sensibilité de 100 %. La plupart des autres plateformes à haut débit avaient des sensibilités de plus de 93 %, à l'exception des dosages des IgG faisant appel à l'analyseur ARCHITECT d'Abbott, dont la sensibilité moyenne était de seulement 87 %. La majorité des plateformes à haut débit avaient également une très bonne spécificité (plus de 97 %). CONCLUSION: La présente étude de compétence démontre que la plupart des dosages sérologiques du SRAS-CoV-2 évalués dans des laboratoires sanitaires provinciaux ou les laboratoires hospitaliers du Canada possèdent une sensibilité acceptable et une excellente spécificité.

Jamestown Canyon and snowshoe hare virus seroprevalence in New Brunswick.

Background: Jamestown Canyon virus (JCV) and snowshoe hare virus (SSHV) are wide-ranging mosquito-borne arboviruses in the California serogroup viruses (CSGV) that are known to circulate in New Brunswick. Despite potential for debilitating central nervous system manifestations, the prevalence of human exposure to these viruses in New Brunswick is unknown. The goal of this study was to quantify rates of human exposure in New Brunswick to these neglected arboviruses. Methods: A retrospective, anonymized provincial serosurvey was performed using a stratified random sample of residual sera submitted between May 2015 and August 2016. To determine the seroprevalence of JCV and SSHV, competitive enzyme-linked immunosorbent assay-positive samples were confirmed positive using plaque-reduction neutralization testing (PRNT). Results: A total of 452 serum samples were screened. The seroprevalence of antibodies against CSGV was estimated to be 31.6% (95% CI 27.4% to 36.1%) with 143 positive samples. PRNT results indicated that most single virus exposures were due to JCV (38 of 143; 26.6%) rather than SSHV (3 of 143; 2.1%). The species of CSGV, to which the remaining 102 seropositive people were exposed, could not be precisely determined. Conclusions: The prevalence of human exposure to CSGV is high but comparable to rates observed in other Atlantic Canadian jurisdictions. Studies such as this provide important baseline epidemiological data regarding the risk of exposure to these neglected arboviruses. SSHV and JCV should be considered in the differential diagnosis for undiagnosed febrile and neuroinvasive illness during mosquito season, particularly when testing for common aetiologies is negative or inconclusive.

Historique : Le virus de Jamestown Canyon (VJC) et le virus du lièvre d'Amérique (VLA) sont des arbovirus à grande portée transmis par des moustiques des virus du sérogroupe Californie (VSGC) qui circulent au Nouveau-Brunswick (NB). Malgré le risque de manifestations débilitantes du système nerveux central, on ne connaît pas la prévalence d'exposition humaine à ces virus au NB. La présente étude visait à quantifier le taux d'exposition humaine à ces arbovirus négligés au NB. Méthodologie : Les chercheurs ont réalisé une enquête sérologique rétrospective provinciale anonymisée au moyen d'un échantillon randomisé stratifié de sérum résiduel soumis entre mai 2015 et août 2016 au dépistage systématique. Ils ont stratifié le processus de sélection selon l'âge, le sexe et la zone de santé régionale afin de garantir un échantillonnage proportionné. Pour déterminer la séroprévalence du VJC et du VLA, ils ont confirmé la positivité des résultats d'échantillons positifs au test ELISA au moyen de tests de séroneutralisation par réduction des plaques (TSRP). Résultats : Au total, 452 échantillons de sérum ont fait l'objet d'un dépistage. Au NB, la séroprévalence des anticorps anti-VSGC était évaluée à 31,6 % (IC à 95 %, 27,4 % à 36,1 %), pour 143 échantillons positifs. Selon les résultats du TSRP, la plupart des expositions à un seul virus étaient causées par le VJC (38 cas sur 143, 26,6 %) plutôt qu'au VLA (trois cas sur 143, 2,1 %). Les espèces de VSGC, auxquelles les 102 autres personnes séropositives ont été exposées, n'ont pas pu être établies avec précision. Conclusions : La prévalence d'exposition humaine au VSGC est élevée, mais comparable aux taux observés dans d'autres régions des provinces de l'Atlantique. Des études comme celle-ci fournissent des données épidémiologiques de référence importantes à l'égard du risque d'exposition humaine à ces arbovirus négligés. Il faut tenir compte du VLA et du VJC dans le diagnostic différentiel de maladie fébrile et neuro-invasive pendant la saison des moustiques, notamment lorsque les tests pour dépister d'autres étiologies courantes sont négatifs ou non concluants.

Evaluation of a commercially-available surrogate virus neutralization test for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).

There remains an urgent need for assays to quantify humoral protective immunity to SARS-CoV-2 to understand the immune responses of COVID-19 patients, evaluate efficacy of vaccine candidates in clinical trials, and conduct large-scale epidemiological studies. The plaque-reduction neutralization test (PRNT) is the reference-standard for quantifying antibodies capable of neutralizing SARS-CoV-2. However, the PRNT is logistically demanding, time-consuming, and requires containment level-3 facilities to safely work with live virus. In contrast, a surrogate virus neutralization test (sVNT) manufactured by Genscript is a quick and simple assay that detects antibodies that inhibit the RBD-ACE2 interaction, crucial for virus entry into host cells. In this study, we evaluate the sensitivity, specificity, and cross-reactivity of the sVNT compared with the PRNT using both 50% and 90% SARS-CoV-2 neutralization as a reference-standard. We found that the sVNT provides a high-throughput screening tool prior to confirmatory PRNT testing for the evaluation of SARS-CoV-2 neutralizing antibodies.

Evaluation of a Commercial Culture-Free Neutralization Antibody Detection Kit for Severe Acute Respiratory Syndrome-Related Coronavirus-2 and Comparison With an Antireceptor-Binding Domain Enzyme-Linked Immunosorbent Assay.

BACKGROUND: Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) surrogate neutralization assays that obviate the need for viral culture offer substantial advantages regarding throughput and cost. The cPass SARS-CoV-2 Neutralization Antibody Detection Kit (GenScript) is the first such commercially available assay that detects antibodies that block receptor-binding domain (RBD)/angiotensin-converting enzyme (ACE)-2 interaction. We aimed to evaluate cPass to inform its use and assess its added value compared with anti-RBD enzyme-linked immunosorbent assays (ELISAs). METHODS: Serum reference panels comprising 205 specimens were used to compare cPass to plaque-reduction neutralization test (PRNT) and a pseudotyped lentiviral neutralization (PLV) assay for detection of neutralizing antibodies. We assessed the correlation of cPass with an ELISA detecting anti-RBD immunoglobulin (Ig)G, IgM, and IgA antibodies at a single timepoint and across intervals from onset of symptoms of SARS-CoV-2 infection. RESULTS: Compared with PRNT-50, cPass sensitivity ranged from 77% to 100% and specificity was 95% to 100%. Sensitivity was also high compared with the pseudotyped lentiviral neutralization assay (93%; 95% confidence interval [CI], 85-97), but specificity was lower (58%; 95% CI, 48-67). Highest agreement between cPass and ELISA was for anti-RBD IgG (r = 0.823). Against the pseudotyped lentiviral neutralization assay, anti-RBD IgG sensitivity (99%; 95% CI, 94-100) was very similar to that of cPass, but overall specificity was lower (37%; 95% CI, 28-47). Against PRNT-50, results of cPass and anti-RBD IgG were nearly identical. CONCLUSIONS: The added value of cPass compared with an IgG anti-RBD ELISA was modest.

A homogeneous split-luciferase assay for rapid and sensitive detection of anti-SARS CoV-2 antibodies.

Better diagnostic tools are needed to combat the ongoing COVID-19 pandemic. Here, to meet this urgent demand, we report a homogeneous immunoassay to detect IgG antibodies against SARS-CoV-2. This serological assay, called SATiN, is based on a tri-part Nanoluciferase (tNLuc) approach, in which the spike protein of SARS-CoV-2 and protein G, fused respectively to two different tNLuc tags, are used as antibody probes. Target engagement of the probes allows reconstitution of a functional luciferase in the presence of the third tNLuc component. The assay is performed directly in the liquid phase of patient sera and enables rapid, quantitative and low-cost detection. We show that SATiN has a similar sensitivity to ELISA, and its readouts are consistent with various neutralizing antibody assays. This proof-of-principle study suggests potential applications in diagnostics, as well as disease and vaccination management.

A simple protein-based surrogate neutralization assay for SARS-CoV-2.

Most of the patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mount a humoral immune response to the virus within a few weeks of infection, but the duration of this response and how it correlates with clinical outcomes has not been completely characterized. Of particular importance is the identification of immune correlates of infection that would support public health decision-making on treatment approaches, vaccination strategies, and convalescent plasma therapy. While ELISA-based assays to detect and quantitate antibodies to SARS-CoV-2 in patient samples have been developed, the detection of neutralizing antibodies typically requires more demanding cell-based viral assays. Here, we present a safe and efficient protein-based assay for the detection of serum and plasma antibodies that block the interaction of the SARS-CoV-2 spike protein receptor binding domain (RBD) with its receptor, angiotensin-converting enzyme 2 (ACE2). The assay serves as a surrogate neutralization assay and is performed on the same platform and in parallel with an ELISA for the detection of antibodies against the RBD, enabling a direct comparison. The results obtained with our assay correlate with those of 2 viral-based assays, a plaque reduction neutralization test (PRNT) that uses live SARS-CoV-2 virus and a spike pseudotyped viral vector-based assay.

West Nile Virus infection in a renal transplant recipient resulting in polioencephalomylelitis, quadriplegia, and global brain atrophy.

An immunosuppressed man developed rapidly progressive neurologic symptoms resulting in quadriplegia. On magnetic resonance imaging multiple areas of abnormal enhancement were observed in the brain, and spinal cord. Serologic evidence of West Nile Virus (WNV) was discovered in the cerebrospinal fluid. This report highlights the catastrophic complications of WNV in an immunocompromised host.

Establishment of a comprehensive and high throughput serological algorithm for Zika virus diagnostic testing.

The previous serological algorithm for Zika virus (ZIKV) comprised screening by anti-ZIKV IgM capture ELISA (MAC-ELISA) for samples collected within 3 months postexposure or onset (MPEO). Samples positive by MAC-ELISA and samples collected beyond 3 MPEO were tested by the confirmatory plaque reduction neutralization test (PRNT), which proved laborious and time-consuming during the 2015 outbreak. Thus, we evaluated several ZIKV ELISAs to establish an anti-IgM and anti-IgG combination for use as a screening tool for all samples prior to PRNT confirmation. The MAC-ELISA or InBios-M in combination with the Euroimmun-G demonstrated sensitivities of 99.1% and 97.2%, respectively, and nonflavivirus specificity of 96.0%. Their cross-reactivities were 71.4% and 50.0%, respectively, for sera positive for Dengue virus antibodies. Due to near-perfect interrater agreement with PRNT and excellent detection of samples collected beyond 3 MPEO, these combinations were recommended as a screening protocol in a new high-throughput algorithm with special considerations for ZIKV diagnostics.