Transmission Of Viral Diseases Research Articles

The Use of Environmental DNA as Preliminary Description of Invertebrate Diversity in Three Sicilian Lakes

Freshwater ecosystems are among the most severely affected environments by species loss caused by climate change and intense anthropogenic pressure. To preserve biodiversity, biomonitoring plays a key role by providing reliable data on biological diversity and ecological status. Environmental DNA (eDNA) metabarcoding has emerged as a powerful and non-invasive alternative to traditional morphology-based sampling and identification methods. This study represents the first application of eDNA analysis to assess the invertebrate communities in three Sicilian Lakes: Poma, Piana degli Albanesi and Scanzano. Water samples were collected at two points in each lake and after filtration with nitrocellulose membranes, eDNA was extracted and metabarcoding analysis was performed. A total of 27 species were identified, belonging to Phyla of Annelida, Arthropoda and Rotifera. Notably, the analysis revealed the presence of alien species (Daphnia parvula and Acanthocyclops americanus), a dangerous species associated with the transmission of viral diseases (Culex pipiens), and potential new records for Sicily (Stylaria lacustris, Platypalpus exilis, Pammene aurana, Limnephilus rhombicus). These results provide a preliminary snapshot of invertebrate biodiversity at these sites, demonstrating how eDNA has the potential to complement, but not replace, traditional methods, contributing to the assessment of ecosystem status.

SARS-CoV-2 transmission dynamics in Mozambique and Zimbabwe during the first 3 years of the pandemic.

The 2019 emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread created a public health emergency of international concern. However, the impact of the pandemic in Sub-Saharan Africa, as documented in cases, hospitalizations and deaths, appears far lower than in the Americas, Europe and Asia. Characterization of the transmission dynamics is critical for understanding how SARS-CoV-2 spreads and the true scale of the pandemic. Here, to better understand SARS-CoV-2 transmission dynamics in two southern African countries, Mozambique and Zimbabwe, we developed a dynamic model-Bayesian inference system to estimate key epidemiological parameters, namely the transmission and ascertainment rates. Total infection burdens (reported and unreported) during the first 3 years of the pandemic were reconstructed using a model-inference approach. Transmission rates rose with each successive wave, which aligns with observations in other continents. Ascertainment rates were found to be low and consistent with other African countries. Overall, the estimated disease burden was higher than the documented cases, indicating a need for improved reporting and surveillance. These findings aid understanding of COVID-19 disease and respiratory virus transmission dynamics in two African countries little investigated to date and can help guide future public health planning and control strategies.

Genomic Evolution and Phylodynamics of the Species Orthomarburgvirus marburgense (Marburg and Ravn Viruses) to Understand Viral Adaptation and Marburg Virus Disease's Transmission Dynamics.

In this review, we investigated the genetic diversity and evolutionary dynamics of the Orthomarburgvirus marburgense species that includes both Marburg virus (MARV) and Ravn virus (RAVV). Using sequence data from natural reservoir hosts and human cases reported during outbreaks, we conducted comprehensive analyses to explore the genetic variability, constructing haplotype networks at both the genome and gene levels to elucidate the viral dynamics and evolutionary pathways. Our results revealed distinct evolutionary trajectories for MARV and RAVV, with MARV exhibiting higher adaptability across different ecological regions. MARV showed substantial genetic diversity and evidence of varied evolutionary pressures, suggesting an ability to adapt to diverse environments. In contrast, RAVV demonstrated limited genetic diversity, with no detected recombination events, suggesting evolutionary stability. These differences indicate that, while MARV continues to diversify and adapt across regions, RAVV may be constrained in its evolutionary potential, possibly reflecting differing roles within the viral ecology of the Orthomarburgvirus marburgense species. Our analysis explains the evolutionary mechanisms of these viruses, highlighting that MARV is going through evolutionary adaptation for human-to-human transmission, alarmingly underscoring the global concern about MARV causing the next pandemic. However, further transdisciplinary One Health research is warranted to answer some remaining questions including the host range and genetic susceptibility of domestic and wildlife species as well as the role of the biodiversity network in the disease's ecological dynamics.

Interplay between a polerovirus and a closterovirus decreases aphid transmission of the polerovirus.

Multi-infection of plants by viruses is very common and can change drastically infection parameters such as virus accumulation, distribution, and vector transmission. Sugar beet is an important crop that is frequently co-infected by the polerovirus beet chlorosis virus (BChV) and the closterovirus beet yellows virus (BYV), both vectored by the green peach aphid (Myzus persicae). These phloem-limited viruses are acquired while aphids ingest phloem sap from infected plants. Here we found that co-infection decreased transmission of BChV by ~50% but had no impact on BYV transmission. The drastic reduction of BChV transmission was due to neither lower accumulation of BChV in co-infected plants nor reduced phloem sap ingestion by aphids from these plants. Using the signal amplification by exchange reaction fluorescent in situ hybridization technique on plants, we observed that 40% of the infected phloem cells were co-infected and that co-infection caused redistribution of BYV in these cells. The BYV accumulation pattern changed from distinct intracellular spherical inclusions in mono-infected cells to a diffuse form in co-infected cells. There, BYV co-localized with BChV throughout the cytoplasm, indicative of virus-virus interactions. We propose that BYV-BChV interactions could restrict BChV access to the sieve tubes and reduce its accessibility for aphids and present a model of how co-infection could alter BChV intracellular movement and/or phloem loading and reduce BChV transmission.IMPORTANCEMixed viral infections in plants are understudied yet can have significant influences on disease dynamics and virus transmission. We investigated how co-infection with two unrelated viruses, BChV and BYV, affects aphid transmission of the viruses in sugar beet plants. We show that co-infection reduced BChV transmission by about 50% without affecting BYV transmission, despite similar virus accumulation rates in co-infected and mono-infected plants. Follow-up experiments examined the localization and intracellular distribution of the viruses, leading to the discovery that co-infection caused a redistribution of BYV in the phloem vessels and altered its repartition pattern within plant cells, suggesting virus-virus interactions. In conclusion, the interplay between BChV and BYV affects the transmission of BChV but not BYV, possibly through direct or indirect virus-virus interactions at the cellular level. Understanding these interactions could be crucial for managing virus propagation in crops and preventing yield losses.

Impact of universal masking in reducing the risk of nosocomial respiratory viruses among people with cancer.

Universal masking within healthcare settings was adopted to combat the spread of coronavirus disease 2019 (COVID-19). In addition to mitigating the risk for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, it also had an added benefit of preventing the nosocomial transmission of other respiratory viral diseases. This study examines the impact of the masking intervention on nosocomial respiratory viral infections (RVI) in vulnerable sub-populations of people with cancer at a tertiary care hospital. Interrupted time series analysis. We reviewed non-SARS-CoV-2 nosocomial RVI between January 1, 2017 and December 31, 2023 and compared its quarterly trends before (January 2017 to March 2020) and after (April 2020 to December 2023) the universal masking intervention was implemented. Prior to the masking policy, there was no significant change in the quarterly rate of non-SARS-CoV-2 nosocomial RVI (baseline trend: P = 0.662). Crude infection rates decreased from 5.6% preintervention to 4.3% after the masking policy was implemented (P < 0.001). Quarterly trends continued to steadily decline post-intervention (β = -0.10, SE = 0.04, P < 0.007). Our results suggest that universal face masking is associated with reduced non-SARS-CoV-2 nosocomial RVI, providing further evidence to support the continued use of face masks in healthcare settings to protect the health of immunocompromised patients.

Modelling COVID-19 mutant dynamics: understanding the interplay between viral evolution and disease transmission dynamics

Understanding virus mutations is critical for shaping public health interventions. These mutations lead to complex multi-strain dynamics often under-represented in models. Aiming to understand the factors influencing variants’ fitness and evolution, we explore several scenarios of virus spreading to gain qualitative insight into the factors dictating which variants ultimately predominate at the population level. To this end, we propose a two-strain stochastic model that accounts for asymptomatic transmission, mutations and the possibility of disease import. We find that variants with milder symptoms are likely to spread faster than those with severe symptoms. This is because severe variants can prompt affected individuals to seek medical help earlier, potentially leading to quicker identification and isolation of cases. However, milder or asymptomatic cases may spread more widely, making it harder to control the spread. Therefore, increased transmissibility of milder variants can still result in higher hospitalizations and fatalities due to widespread infection. The proposed model highlights the interplay between viral evolution and transmission dynamics. Offering a nuanced view of factors influencing variant spread, the model provides a foundation for further investigation into mitigating strategies and public health interventions.

Influence of internal heating and natural convection on airborne transmission of viral diseases

Influence of internal heating and natural convection on airborne transmission of viral diseases

Factors Contributing to Emergence of infectious viral diseases in India: Issues and Challenges after COVID-19 Pandemic

Emerging and re-emerging viral infections are major cause of morbidity and mortality in humans and animals. India had experienced numerous infectious disease outbreaks and epidemics in past years. However, tremendous strides have been achieved in the past in the fight against serious epidemic diseases. It has been found that a wide range of complex factors, such as pathogen evolution, human invasion, commerce in wild animals, microbial adaptation, changes in the environment and dynamic interactions between humans and animals influence the emergence and transmission of infectious viral diseases. As the COVID-19 pandemic demonstrated, India's secondary and tertiary health-care system is quite advanced. The study of infectious diseases, in particular their pathogenesis, genetic profile and diagnosis has fundamentally changed with the advent of genome sequencing and nucleic acid detection technology. Additionally, advance therapy and vaccination led to best possible patient management and care. Further scientific investigations and research are needed to discover neglected diseases that have the potential to cause epidemics as well as to develop updated vaccines, modern treatment strategy and diagnostics at molecular level. This evaluation will aid for policymakers, academics and researchers to redesign the course of action to combat the deadly emerging pathogenic viruses and also preserve the ecosystem.

Evaluation of coating materials on the characterization of size and viability of virus-laden particles collected with an Andersen cascade impactor

Airborne pathogens are typically associated with particles, and the transport behavior of these particles is largely driven by their size. To better understand airborne transmission of viral diseases and develop effective control measures, proper size characterization of virus-laden particles is essential. The Andersen cascade impactor (ACI) is an 8-stage air sampler that separates aerosol particles into 9 aerodynamic size fractions. During sampling with an ACI under certain conditions, particles may bounce upon impact with the collection plates of the ACI, leading to eventual deposition on a stage further downstream than their target stage. Coating collection plates with adhesive materials may help decrease particle bounce; however, it may also affect the viability of collected pathogens. In this study, we evaluated different materials for their ability to minimize particle bounce while conserving virus viability during the collection of viral aerosol particles with an ACI. We evaluated nine materials - Tween® 80, silicone oil, Span® 85, Brij® 35, glycerol, mineral oil, gelatin, bovine serum albumin, and virus growth media - on their effect to inactivate H1N1 influenza virus and bovine coronavirus, a surrogate of SARS-CoV-2. Plates coated with gelatin, silicone oil, and mineral oil resulted in the least reduction of viability for both viruses. These materials were then used to sample viral aerosol particles in a wind tunnel. Results of physical particle collection, viral load and viral viability from the various ACI stages revealed no significant differences in aerodynamic size distribution between coated and uncoated plates, and the size distribution was similar to that reported by an optical particle sizer. Overall, our results did not support the need to coat ACI collection plates when characterizing viral aerosol particles under the conditions of this study. However, we did identify potential coating materials which could conserve virus viability maximally, if particle bounce is of concern.

Mixed viral infections in vegetable crops: biochemical and molecular aspects

Mixed viral infections refer to the coinfection of two or more viruses in the plant, which regularly lead to exacerbated symptoms on leaves and fruits. The dynamics of coinfections may follow either a synergistic, antagonistic, or neutral interaction that impacts the severity of the symptoms and infection. Mixed viral infections occur due to the convergence of fundamental characteristics reviewed in this manuscript. The virus‒host plant interrelationship influences the establishment and spread patterns of mixed viral infections. Attention should be drawn to potential changes in the dynamics of transmission and prevalence of plant viral diseases due to the effect of anthropogenic and natural alterations to complex agroecological systems or their components, including hosts, reservoirs, vectors, ecological niches, and the emergence of new virus strains.

Diversity of symbiotic bacteria in the reproductive tracts and midgut of Culex pipiens

Background: Culex pipiens is considered a vector for the transmission of infectious, viral, and parasitic diseases. To control this mosquito vector, investigating symbiotic bacteria colonized inside the mosquitoes’ organs to impede the transmission of pathogens has been of recent interest to researchers. Methods: This revision was intended to provide a comprehensive overview of the diversity of endosymbiont bacteria residing in different tissues of Cx. pipiens globally by using reports in Google Scholar, PubMed, and Science Direct until May 2024. Result: The results showed that more than 50 bacterial genera have been reported in Culex tissues, in which the bacterial diversity was higher in the midgut than eggs or the whole body in Cx. pipiens. More than 65% of samples were insect-reared mosquitoes than wild types. Various methods based on culture-dependent and culture-independent approaches followed by molecular techniques such as 16SrRNA Illumina sequencing, Next Generation Sequencing (NGS), RNA shotgun metagenomic sequencing (RNA-seq), RTPCR, and MALDI-TOF MS have been used for the recognition of bacteria at genera or species levels. The most favorable gene for molecular analysis via PCR is 16SrRNA; however, the wsp gene was another candidate used for identification of the bacterial community. Conclusion: These results provide a library of defined bacteria associated with Cx. pipiens. The characterization of tissue-specific and host-specific bacterial communities sheds light on further studies pursuing the functional role of endosymbiont organisms in control strategies and vector biology.

The effect of human heterogeneity on the transmission of viral respiratory diseases under air pollution

The impact of air pollutants on the human respiratory system has received more and more attention. However, due to the differences in human characteristics and the strength of protective measures, different people have different symptoms in air pollution and viral infection environments. In this paper, an SI1I2P dynamic model of respiratory diseases infected by virus under air pollution is established by introducing air pollutant concentration compartment. Qualitative research shows that there are seven equilibria in the system, the daily average emission and clearance rate of pollutants are the key parameters affecting the existence and stability of equilibria. In this paper, by using Sotomayor’s theorem and center manifold theory, it is proved that the system undergoes saddle–node bifurcation or Bogdanov–Takens bifurcation of co-dimension 3 at the boundary equilibrium, and exhibits saddle–node bifurcation at the endemic equilibrium. Numerical simulation results show that wearing masks in haze weather can not only reduce the number of allergic patients, but also reduce the number of viral patients. In addition, reducing the daily average emission of air pollution and increasing its clearance rate can also reduce the number of allergic patients. It is worth mentioning that this measure is more effective in controlling viral respiratory diseases.

Carbon‐Based Nanomaterials for Antiviral Applications

AbstractIn the antimicrobial resistance era, carbon‐based nanomaterials (CBNs) such as fullerenes, carbon dots, graphene, and their derivatives are promising therapeutic tools in combating viral diseases. This review shows that these materials have broad‐spectrum antiviral activity against 33 viruses belonging to different Baltimore groups. CBNs also exhibit antimicrobial activity against bacteria and fungi and possess a low risk of selecting for resistance, since their primary mode of antimicrobial action involves physically damaging the microbes. CBNs also offer additional promising properties, including enhanced antiviral effectiveness under diverse types of irradiation and facilitating antiviral immune responses. Their potential as antiviral agents is still in its infancy and future research should focus on their toxicity, antiviral mechanisms, pharmacokinetics, and bioavailability. They are also potential antiviral materials for preventing the transmission of viral diseases for use in face masks, shields, hospital and airport surfaces, and elevators, among others. It is anticipated that CBNs will play an increasingly significant role in the fight against viruses and infectious diseases.

Within-Host Viral Growth and Immune Response Rates Predict Foot-and-Mouth Disease Virus Transmission Dynamics for African Buffalo.

AbstractInfectious disease dynamics operate across biological scales: pathogens replicate within hosts but transmit among populations. Functional changes in the pathogen-host interaction thus generate cascading effects across organizational scales. We investigated within-host dynamics and among-host transmission of three strains (SAT-1, -2, -3) of foot-and-mouth disease viruses (FMDVs) in their wildlife host, African buffalo. We combined data on viral dynamics and host immune responses with mathematical models to ask the following questions: How do viral and immune dynamics vary among strains? Which viral and immune parameters determine viral fitness within hosts? And how do within-host dynamics relate to virus transmission? Our data reveal contrasting within-host dynamics among viral strains, with SAT-2 eliciting more rapid and effective immune responses than SAT-1 and SAT-3. Within-host viral fitness was overwhelmingly determined by variation among hosts in immune response activation rates but not by variation among individual hosts in viral growth rate. Our analyses investigating across-scale linkages indicate that viral replication rate in the host correlates with transmission rates among buffalo and that adaptive immune activation rate determines the infectious period. These parameters define the virus's relative basic reproductive number (ℛ0), suggesting that viral invasion potential may be predictable from within-host dynamics.

A multi-species, multi-pathogen avian viral disease outbreak event: Investigating potential for virus transmission at the wild bird – poultry interface

ABSTRACT A free-range organic broiler (Gallus gallus domesticus) premises in Staffordshire was infected by high pathogenicity avian influenza virus (HPAIV) H5N8 during the 2020–2021 epizootic in the United Kingdom (UK). Following initial confirmation of the infection in poultry, multiple wild bird species were seen scavenging on chicken carcasses. Detected dead wild birds were subsequently demonstrated to have been infected and succumbed to HPAIV H5N8. Initially, scavenging species, magpie (Pica pica) and raven (Corvus corax) were found dead on the premises but over the following days, buzzards (Buteo buteo) were also found dead within the local area with positive detection of HPAIV in submitted carcasses. The subacute nature of microscopic lesions within a buzzard was consistent with the timeframe of infection. Finally, a considerable number of free-living pheasants (Phasianus colchicus) were also found dead in the surrounding area, with carcasses having higher viral antigen loads compared to infected chickens. Limited virus dissemination was observed in the carcasses of the magpie, raven, and buzzard. Further, an avirulent avian paramyxovirus type 1 (APMV-1) was detected within poultry samples as well as in the viscera of a magpie infected with HPAIV. Immunohistochemistry did not reveal colocalization of avian paramyxovirus antigens with lesions, supporting an avirulent APMV-1 infection. Overall, this case highlights scenarios in which bi-directional transmission of avian viral diseases between commercial and wild bird species may occur. It also underlines the importance of bio separation and reduced access when infection pressure from HPAIV is high.

Larval mosquito predation: evaluation of the effectiveness of five aquatic arthropod species against larvae of Culex pipiens Linnaeus, 1758 (Diptera: Culicidae)

ABSTRACT Mosquitoes are insects of medical interest. They contribute to the transmission and spread of many viral and parasitic diseases. Various methods have been used to control mosquitoes such as conventional insecticides, which are widely used throughout the world and have a negative impact on the environment and targeted species. Predatory insects are significant for the biocontrol of various pests, including the important potential against the larval instars of mosquitoes. In this study, we tested the efficacy of five species Piona uncata Koenike, 1888; Notonecta glauca Linnaeus, 1758; Corixa punctata Illiger, 1807, Ilyocoris cimicoide Linnaeus, 1758; and Sympetrum striolatum Charpentier, 1840 against the fourth instars larvae of Culex pipiens Linnaeus, 1758, according to two exposure phases (Light phase, Twilight phase). The predation assays show a significant effect of tested species against mosquito larvae with the following decreasing order of efficacy: S. striolatum> N. gluca> P. uncata> I. cimicoides> C. pinctata. The early larval instars are the most favourable trophic choice of the five predatory species. On the other hand, we noticed a difference in the predation rate for each species during the two experimental periods. The light phase exhibits the highest predatory efficacy than the twilight phase.

Subclinical infection caused by a recombinant vaccine-like strain poses high risks of lumpy skin disease virus transmission.

Lumpy skin disease (LSD) is a transboundary viral infection, affecting cattle with characteristic manifestations involving multiple body systems. A distinctive characteristic of lumpy skin disease is the subclinical disease manifestation wherein animals have viremia and shed the virus through nasal and ocular discharges, while exhibiting no nodules but enlarged lymph nodes that are easily oversighted by inexperienced vets. Further research on the role of subclinically ill animals in the transmission of LSD virus (LSDV) can contribute to the development of more effective tools to control the disease worldwide. Thus, this study aims to determine the potential role of subclinical infection in virus transmission in a non-vector-borne manner. To achieve this, we inoculated animals with the recombinant vaccine-like strain (RVLS) Udmurtiya/2019 to cause clinical and subclinical LSDV infection. After the disease manifestation, we relocated the subclinically ill animals to a new clean facility followed by the introduction of another five animals to determine the role of RVLS-induced subclinical infection in the virus transmission via direct/indirect contact. After the introduction of the naïve animals to the relocated subclinically ill ones in a shared airspace, two introduced animals contracted the virus (clinically and subclinically), showing symptoms of fever, viremia, and seroconversion in one animal, while three other introduced animals remained healthy and PCR-negative until the end of the study. In general, the findings of this study suggest the importance of considering LSDV subclinical infection as a high-risk condition in disease management and outbreak investigations.

Virus detection light diffraction fingerprints for biological applications.

The transmission of viral diseases is highly unstable and highly contagious. As the carrier of virus transmission, cell is an important factor to explore the mechanism of virus transmission and disease. However, there is still a lack of effective means to continuously monitor the process of viral infection in cells, and there is no rapid, high-throughput method to assess the status of viral infection. On the basis of the virus light diffraction fingerprint of cells, we applied the gray co-occurrence matrix, set the two parameters effectively to distinguish the virus status and infection time of cells, and visualized the virus infection process of cells in high throughput. We provide an efficient and nondestructive testing method for the selection of excellent livestock and poultry breeds at the cellular level. Meanwhile, our work provides detection methods for the recessive transmission of human-to-human, animal-to-animal, and zoonotic diseases and to inhibit and block their further development.

Inhibition of PEDV viral entry upon blocking N-glycan elaboration

Porcine Epidemic Diarrhea Virus (PEDV) poses a significant threat to the global swine industry, demanding a thorough understanding of its cellular invasion mechanism for effective interventions. This study meticulously investigates the impact of O- and N-linked glycans on PEDV proteins and host cell interaction, shedding light on their influence on the virus's invasion process.Utilizing CRISPR-Cas9 technology to inhibit cell surface O- and N-linked glycan synthesis demonstrated no discernible impact on virus infection. However, progeny PEDV strains lacking these glycans exhibited a minor effect of O-linked glycans on virus infection. Conversely, a notable 40% reduction in infectivity was observed when the virus surface lacked N-linked glycans, emphasizing their pivotal role in facilitating virus recognition and binding to host cells.Additionally, inhibition studies utilizing kifunensine, a natural glycosidase I inhibitor, reaffirmed the significant role of N-linked glycans in virus infection. Inhibiting N-linked glycan synthesis with kifunensine substantially decreased virus entry into cells and potentially influenced spike protein expression.Assessment of the stability and recovery potential of N-linked glycan-deficient strains underscored the critical importance of N-glycans at various stages of the virus lifecycle. In vivo experiments infecting piglets with N-glycan-deficient strains exhibited milder clinical symptoms, reduced virus excretion, and less severe pathological lesions compared to conventional strains.These findings offer promising translational applications, proposing N-glycosylation inhibitors as potential therapeutic interventions against PEDV. The utilization of these inhibitors might mitigate virus invasion and disease transmission, providing avenues for effective antiviral strategies and vaccine development. Nonetheless, further research is warranted to elucidate the precise mechanisms of N-linked glycans in PEDV infection for comprehensive clinical applications.

Tips and tools to obtain and assess mosquito viromes.

Due to their vectorial capacity, mosquitoes (Diptera: Culicidae) receive special attention from health authorities and entomologists. These cosmopolitan insects are responsible for the transmission of many viral diseases, such as dengue and yellow fever, causing huge impacts on human health and justifying the intensification of research focused on mosquito-borne diseases. In this context, the study of the virome of mosquitoes can contribute to anticipate the emergence and/or the reemergence of infectious diseases. The assessment of mosquito viromes also contributes to the surveillance of a wide variety of viruses found in these insects, allowing the early detection of pathogens with public health importance. However, the study of mosquito viromes can be challenging due to the number and complexities of steps involved in this type of research. Therefore, this article aims to describe, in a straightforward and simplified way, the steps necessary for obtention and assessment of mosquito viromes. In brief, this article explores: the capture and preservation of specimens; sampling strategies; treatment of samples before DNA/RNA extraction; extraction methodologies; enrichment and purification processes; sequencing choices; and bioinformatics analysis.