Wastewater sequencing uncovers early, cryptic SARS-CoV-2 variant transmission

As SARS-CoV-2 becomes an endemic pathogen, detecting emerging variants early is critical for public health interventions. Inferring lineage prevalence by clinical testing is infeasible at scale, especially in areas with limited resources, participation, or testing/sequencing capacity, which can also introduce biases. SARS-CoV-2 RNA concentration in wastewater successfully tracks regional infection dynamics and provides less biased abundance estimates than clinical testing. Tracking virus genomic sequences in wastewater would improve community prevalence estimates and detect emerging variants. However, two factors limit wastewater-based genomic surveillance: low-quality sequence data and inability to estimate relative lineage abundance in mixed samples. Here, we resolve these critical issues to perform a high-resolution, 295-day wastewater and clinical sequencing effort, in the controlled environment of a large university campus and the broader context of the surrounding county. We develop and deploy improved virus concentration protocols and deconvolution software that fully resolve multiple virus strains from wastewater. We detect emerging variants of concern up to 14 days earlier in wastewater samples, and identify multiple instances of virus spread not captured by clinical genomic surveillance. Our study provides a scalable solution for wastewater genomic surveillance that allows early detection of SARS-CoV-2 variants and identification of cryptic transmission.

Transgenic Elite Lines of Carioca Seeded Common Bean (Phaseolus Vulgaris L.) With Multiple Resistance to Viruses Reduce Cowpea Mild Mottle Virus Transmission

The most important viruses infecting common bean (Phaseolus vulgaris L.) in Brazil are BCMV, BGMV and CPMMV, the last two transmitted by the whitefly Bemisia tabaci, occurring simultaneously and causing severe yield losses. Genetically modified progenies of common bean, from carioca market class and multiple virus resistance (BCMV, BGMV and CPMMV), have been developed using conventional breeding and molecular tools. Agronomic performance and virus disease severity (VS) evaluated in two field trials, selected 39 elite progenies out of 477. Molecular analyses identified the presence of BCMV and BGMV resistance alleles in plants. CPMMV resistance was measured on mechanically inoculated plants using a VS scoring scale. Among the lowest VS average scores, five progenies showed resistance to BCMV, BGMV and CPMMV, and upright plant architecture, resistance to plant lodging and carioca market class grains, presenting potential to be developed into a new transgenic cultivar, with multiple virus resistance. Additionally, the resistant progenies may also contribute to reduce virus spread in the field, as they were a less efficient inoculum source of CPMMV in insect transmission assays.

The mucosal barrier and anti-viral immune responses can eliminate portions of the viral population during transmission and early viral growth

Little is known about how specific individual viral lineages replicating systemically during acute Human Immunodeficiency Virus or Simian Immunodeficiency Virus (HIV/SIV) infection persist into chronic infection. In this study, we use molecularly barcoded SIV (SIVmac239M) to track distinct viral lineages for 12 weeks after intravenous (IV) or intrarectal (IR) challenge in macaques. Two Mafa-A1*063+ cynomolgus macaques (Macaca fascicularis, CM) were challenged IV, and two Mamu-A1*001+ rhesus macaques (Macaca mulatta, RM) were challenged IR with 200,000 Infectious Units (IU) of SIVmac239M. We sequenced the molecular barcode of SIVmac239M from all animals over the 12 weeks of the study to characterize the diversity and persistence of virus lineages. During the first three weeks post-infection, we found ~70–560 times more unique viral lineages circulating in the animals challenged IV compared to those challenged IR, which is consistent with the hypothesis that the challenge route is the primary driver restricting the transmission of individual viral lineages. We also characterized the sequences of T cell epitopes targeted during acute SIV infection, and found that the emergence of escape variants in acutely targeted epitopes can occur on multiple virus templates simultaneously, but that elimination of some of these templates is likely a consequence of additional host factors. These data imply that virus lineages present during acute infection can still be eliminated from the systemic virus population even after initial selection.

Extended Characterisation of Five Archival Tick-borne Viruses Provides Insights for Virus Discovery in Australian Ticks

BackgroundA subset of Australians who have been bitten by ticks experience a complex of chronic and debilitating symptoms which cannot be attributed to the known pathogenic species of bacteria present in Australia. As a result, there has been a renewed effort to identify and characterise viruses in Australian terrestrial ticks. Recent transcriptome sequencing of Ixodes and Amblyomma ticks have revealed the presence of multiple virus sequences. However, without virus isolates our ability to understand the host-range and pathogenesis of newly identified viruses is limited. We have established a successful method for high-throughput virus discovery and isolation in mosquitoes using antibodies to double-stranded RNA. In this study we sought to characterise five archival tick-borne viruses in order to adapt our virus discovery protocol for Australian ticks.MethodsWe performed virus characterisation using a combination of bioinformatic sequence analysis and in vitro techniques including replication kinetics, antigenic profiling, virus purification and mass spectrometry. ResultsOur sequence analysis of three archival viruses revealed marked genetic stability in isolates collected from the same location approximately 30 years apart. We demonstrate that the Ixodes scapularis-derived ISE6 cell line supports replication of Australian members of the Flaviviridae, Nairoviridae, Phenuiviridae and Reoviridae families, including a virus isolated from the soft tick Ornithodoros capensis. While antibodies against double-stranded RNA could be used to detect replication of a tick-borne reovirus and mosquito-borne flavivirus, the tick-borne flaviviruses Gadgets Gully virus and Saumarez Reef virus could not be detected using this method. Finally, four novel virus-like sequences were identified in transcriptome sequencing of the Australian native tick Ixodes holocyclus.ConclusionsGenetic and antigenic characterisation of archival viruses in this study confirm that three viruses described in 2002 represent contemporary isolates of virus species first identified 30 years prior. Our findings with antibodies to double-stranded RNA highlight an unusual characteristic shared by two Australian tick-borne flaviviruses. Overall, this work provides a valuable resource for isolation of Australian tick-borne viruses using existing cell lines.

Neutralization of Dengue Virus Serotypes by Sera from Dengue-Infected Individuals Is Preferentially Directed to Heterologous Serotypes and Not against the Autologous Serotype Present in Acute Infection

Sequential infections of humans by the four different dengue serotypes (DENV-1–4) lead to neutralizing antibodies with group, cross, and type specificity. Virus neutralization of serotypes showed monotypic but mostly multitypic neutralization profiles due to multiple virus exposures. We have studied neutralization to heterologous, reference DENV serotypes using paired sera collected between days 6 and 37 after onset of fever. The DENV-primed neutralization profile of the first serum sample, which was monitored by a foci reduction neutralization test (FRNT), was boosted but the neutralization profile stayed unchanged in the second serum sample. In 45 of 47 paired serum samples, the predominant neutralization was directed against DENV serotypes distinct from the infecting serotype. Homologous neutralization studies using sera and viruses from the same area, 33 secondary sera from DENV-1 infected Cambodian patients and eight virus isolates from Cambodia, showed that the FRNT assay accurately predicted the lack of a predominant antibody response against the infecting DENV-1 serotype in contrast to FRNT results using the WHO set of DENV viruses. This report provides evidence that DENV-primed multitypic neutralizing antibody profiles were mainly boosted and stayed unchanged after secondary infection and that DENV neutralization was predominantly directed to heterologous DENV but not against the infecting homologous serotype.

Genetic and Antigenic Characterization of an Influenza A(H3N2) Outbreak in Cambodia and the Greater Mekong Subregion during the COVID-19 Pandemic, 2020

Introduction of non-pharmaceutical interventions to control COVID-19 in early 2020 coincided with a global decrease in active influenza circulation. However, between July and November 2020, an influenza A(H3N2) epidemic occurred in Cambodia and in other neighboring countries in the Greater Mekong Subregion in Southeast Asia. We characterized the genetic and antigenic evolution of A(H3N2) in Cambodia and found that the 2020 epidemic comprised genetically and antigenically similar viruses of Clade3C2a1b/131K/94N, but they were distinct from the WHO recommended influenza A(H3N2) vaccine virus components for 2020-2021 Northern Hemisphere season. Phylogenetic analysis revealed multiple virus migration events between Cambodia and bordering countries, with Laos PDR and Vietnam also reporting similar A(H3N2) epidemics immediately following the Cambodia outbreak: however, there was limited circulation of these viruses elsewhere globally. In February 2021, a virus from the Cambodian outbreak was recommended by WHO as the prototype virus for inclusion in the 2021-2022 Northern Hemisphere influenza vaccine. Importance The 2019 coronavirus disease (COVID-19) pandemic has significantly altered the circulation patterns of respiratory diseases worldwide and disrupted continued surveillance in many countries. Introduction of control measures in early 2020 against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection has resulted in a remarkable reduction in the circulation of many respiratory diseases. Influenza activity has remained at historically low levels globally since March 2020, even when increased influenza testing was performed in some countries. Maintenance of the influenza surveillance system in Cambodia in 2020 allowed for the detection and response to an influenza A(H3N2) outbreak in late 2020, resulting in the inclusion of this virus in the 2021-2022 Northern Hemisphere influenza vaccine.

Advanced Digital Health Care Information Sharing for Covid19- Version 2.0

The covid-19 virus has been linked to an acute outbreak of the disease that has passed for years. Clear explanations of these should be provided by trained professionals and those with healthcare experience who have the energy to work on intensive care. The World Health Organization (WHO) has taken various steps to address this. These can be audited by NETCCN (National Emergency Telecritical Care Network) using digital technology. This section explains a lot. It is proposed by the National Emergency Telecritical Care Network (NETCCN). This digital health information will be solved as an updated version 2.0, which will greatly improve future emergencies. The proposed method of digital predication support for Artificial Intelligent (AI). Use these to learn historical information about the virus. This technology can detect telemetry, complex maintenance robotics and monitoring intelligence. These can be developed to integrate multiple virus-related information. All of these will be coordinated by health professionals. Frequently testing should be done to ensure continued readiness to protect against emergency disasters.

Epidemic Modeling of Multiple Virus Strains: A Case Study of SARS-CoV-2 B.1.1.7 In Moscow

During a long-running pandemic a pathogen can mutate, producing new strains with different epidemiological parameters. Existing approaches to epidemic modeling only consider one virus strain. We have developed a modified Susceptible-Exposed-Infected-Recovered model to simulate multiple virus strains within the same population. As a case study, we investigate the potential effects of SARS-CoV-2 strain B.1.1.7 on the city of Moscow. Our analysis indicates a high risk of a new wave of infections in September-October 2021 with up to 35 000 daily infections at peak. We open-source our code and data.

Scalable, Micro-Neutralization Assay for Assessment of SARS-CoV-2 (COVID-19) Virus-Neutralizing Antibodies in Human Clinical Samples

As the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic expanded, it was clear that effective testing for the presence of neutralizing antibodies in the blood of convalescent patients would be critical for development of plasma-based therapeutic approaches. To address the need for a high-quality neutralization assay against SARS-CoV-2, a previously established fluorescence reduction neutralization assay (FRNA) against Middle East respiratory syndrome coronavirus (MERS-CoV) was modified and optimized. The SARS-CoV-2 FRNA provides a quantitative assessment of a large number of infected cells through use of a high-content imaging system. Because of this approach, and the fact that it does not involve subjective interpretation, this assay is more efficient and more accurate than other neutralization assays. In addition, the ability to set robust acceptance criteria for individual plates and specific test wells provided further rigor to this assay. Such agile adaptability avails use with multiple virus variants. By February 2021, the SARS-CoV-2 FRNA had been used to screen over 5000 samples, including acute and convalescent plasma or serum samples and therapeutic antibody treatments, for SARS-CoV-2 neutralizing titers.

The Mucosal Barrier and Anti-Viral Immune Responses can Eliminate Portions of the Viral Population during Transmission and Early Viral Growth

Little is known about how individual virus lineages replicating during acute Human Immunodeficiency Virus or Simian Immunodeficiency Virus (HIV/SIV) infection persist into chronic infection. In this study, we use molecularly barcoded SIV (SIVmac239M) to track distinct viral lineages for 12 weeks after intravenous and intrarectal challenge in macaques. Two Mafa-A1*063+ cynomolgus macaques (Macaca fascicularis) were challenged intravenously (IV), and two Mamu-A1*001+ rhesus macaques (Macaca mulatta) were challenged intrarectally (IR) with 200,000 Infectious Units (IU) of SIVmac239M. We deep sequenced the molecular barcode from all animals over 12 weeks to characterize the diversity and persistence of virus lineages, as well as the sequences of T cell epitopes during acute SIV infection. During the first three weeks post-infection, we found ~175-950 times more unique virus lineages circulating in the animals challenged intravenously than those challenged intrarectally, suggesting that challenge route is the primary driver restricting the transmission of individual viral lineages. Additionally, the emergence of escape variants can occur on multiple virus templates simultaneously, but elimination of some templates is likely a consequence of additional host factors. These data imply that virus lineages present during acute infection can be eliminated from the virus population even after initial T cell selection.