Virus Transmission Research Articles

Transient Dynamics of a Porous Sphere in a Linear Fluid

This article describes the unsteady translational motion of a porous sphere with slip-surface in a quiescent viscous fluid. Apart from its radius a and density ρs , the particle is characterized by its permeability parameter γ , slip-length l and effective viscosity-ratio ϵ for interior flow. The Reynolds number for the system is assumed to be small leading to negligible convective contribution, though the transient inertia for both the liquid and the solid is comparable to viscous forces. The resulting linearized but unsteady flow-equations for both inside and outside the porous domain are solved in time-invariant frequency domain by satisfying appropriate boundary conditions. The analysis ultimately renders frequency-dependent hydrodynamic friction for the suspended body. The frictional coefficient is computed under both low and high frequency limit for different values of γ, l and ϵ so that the findings can be compared to known results with impermeable surface. Moreover, the parametric exploration shows that the sphere acts like a no-slip body even with non-zero l if aγ ≫ 1/√ϵ . Scaling arguments from a novel boundary layer theory for flow inside porous media near interfaces explain this rather unexpected observation. Also, computed fluid resistance is incorporated in equation of motion for the particle to determine its time-dependent velocity response to a force impulse. This transient response shows wide variability with ρs, γ, l and ϵ insinuating the significance of the presented study. Consequently, the paper concludes that slip and permeability should be viewed as crucial features of submicron particles if unexpected variability is to be explained in nano-scale phenomena like nano-fluidic heat conduction or viral transmission. Thus, the theory and findings in this paper will be immensely useful in modeling of nano-particle dynamics.

Representative honey bee viruses do not replicate in the small hive beetle, Aethina tumida Murray

The small hive beetle (SHB), Aethina tumida Murray, is an invasive pest of the honey bee and causes significant damage through the consumption of colony resources and brood. Two assumptions related to honey bee virus transmission have been made about SHB: first, that SHB vectors honey bee viruses and second, that these viruses replicate in SHB based on the detection of both positive and negative strand viral genomic RNA within SHB. To clarify the role of SHB in virus transmission, we sought to address whether selected honey bee viruses replicate in SHB. Sequences derived from five honey bee viruses were identified in the transcriptomes of field-caught SHB from the U.S., but not in those of lab-reared SHB, suggesting that these viruses do not replicate in SHB. To elucidate whether the representative viruses, Israeli acute paralysis virus (IAPV; Dicistroviridae) and Deformed wing virus (DWV; Iflaviridae) replicate in SHB, we tested for replication in vitro in an SHB-derived cell line (BCIRL-AtumEN-1129-D6). Following treatment of the cell line with viral particles or viral RNA, the number of virus genomes was monitored by reverse transcription quantitative PCR (RT-qPCR). In contrast to the positive control, IAPV and DWV RNA levels steadily decreased over a period of 8 days. Collectively, these results from bioinformatic observations and in vitro experiments indicate that IAPV and DWV do not replicate in SHB. These results are consistent with the host specificity of most insect viruses within a single insect order and indicate that while SHB may serve as a mechanical vector of honey bee viruses within and between hives, this insect does not serve as a biological vector for these honey bee viruses.

Patterns of the within-host evolution of human norovirus in immunocompromised individuals and implications for treatment

Currently, there is no licensed treatment for chronic norovirus infections, but the use of intra-duodenally-delivered immunoglobulins is promising; nevertheless, varying results have limited their wide use. Little is known about the relationship between norovirus genetic diversity and treatment efficacy. We analyzed the norovirus within-host diversity and evolution in a cohort of 20 immunocompromised individuals using next-generation sequencing (NGS) and clone-based sequencing of the capsid (VP1) gene. Representative VP1s were expressed and their glycan receptor binding affinity and antigenicity were evaluated. The P2 domain, within the VP1, accumulated up to 30-fold more non-synonymous mutations than other genomic regions. Intra-host virus populations in these patients tended to evolve into divergent lineages that were often antigenically distinct. Several of these viruses were widely resistant to binding-blocking antibodies in immunoglobulin preparations. Notably, for one patient, a single amino-acid substitution in the P2 domain resulted in an immune-escape phenotype, and it was likely the main contributor to treatment failure. Furthermore, we found evidence for transmission of late-stage viruses between two immunocompromised individuals. The findings demonstrated that within-host noroviruses in chronic infections tend to evolve into antigenically distinct subpopulations. This antigenic evolution was likely caused by the remaining low immunity levels exerted by immunocompromised individuals, possibly undermining antiviral treatment. Our observations provide insights into norovirus (within-host) evolution and treatment. Erasmus MC grant mRACE, the European Union's Horizon 2020 research and innovation program under grant agreement No. 874735 (VEO), and the NWO STEVIN award (Koopmans).

Mass gathering events and COVID-19; lessons learnt from the 2020 European football championship.

Evidence about the impact of mass gatherings during the coronavirus disease 2019 (COVID-19) pandemic on the number of disease cases and on the health-care systems of host countries is limited. Additionally, there have been few publications on the lessons identified from the adaptation of mass gatherings held during the pandemic, including the implementation of comprehensive public health and social measures aimed at reducing viral transmission. This article describes preparations made for the 2020 Union of European Football Associations (UEFA) European Football Championship (UEFA Euro 2020) by the World Health Organization's (WHO) Regional Office for Europe, UEFA and other stakeholders after the championship had been rescheduled because of the COVID-19 pandemic. Technical guidance on preparations for the football tournament and risk assessment tools were provided by WHO. A task force established by the WHO Regional Office for Europe conducted traditional and event-based disease surveillance before and during UEFA Euro 2020, monitored public health and social measures in the 11 host countries, and developed a risk communication and community engagement strategy that involved multimedia campaigns targeting news and social media, fans, athletes, event organizers and other stakeholders. The lessons and good practices identified during UEFA Euro 2020 are described to help guide preparations for future mass gatherings in health emergencies. Sharing data and recommendations on best practice from previous mass gatherings with the organizers and countries involved in planning for a major event is particularly important.

The comparative study between treatment with Cryoprecipitate and recombinant Factor VIII in Hemophilia in children

Introduction: Hemophilia A is a genetic disorder caused by a deficiency or absence of coagulation Factor VIII, leading to impaired blood clotting and prolonged bleeding, especially into joints and muscles. Without appropriate treatment, recurrent bleeding can result in chronic joint damage and disability. Traditionally, Cryoprecipitate, a blood product containing concentrated clotting factors, has been used to manage bleeding episodes in patients with Hemophilia A. However, with advancements in biotechnology, recombinant Factor VIII, a synthetic product, has become an alternative. Recombinant Factor VIII eliminates the risks associated with blood-derived products, such as viral transmission, and offers more consistent dosing and availability. Despite these advantages, recombinant therapies are significantly more expensive. This study seeks to compare the clinical efficacy, safety of Cryoprecipitate versus recombinant Factor VIII in pediatric patients with Hemophilia A, providing critical insights for optimal management strategies. Purpose: The purpose of this study is to compare the clinical outcomes, safety of Cryoprecipitate versus recombinant Factor VIII in the management of children diagnosed with Hemophilia A. Materials and methods: This retrospective study included 32 pediatric patients diagnosed with Hemophilia A, treated either with Cryoprecipitate or recombinant Factor VIII. Clinical data were collected on bleeding frequency, Factor VIII recovery. Statistical analyses were conducted to determine significant differences between the two groups. Results: The study demonstrated that treatment with recombinant Factor VIII resulted in significantly improved clinical outcomes compared to Cryoprecipitate. In the group treated with recombinant Factor VIII, patients required scheduled hospitalizations for routine follow-up and management, with no reports of acute bleeding episodes during these admissions. This contrasts sharply with the Cryoprecipitate group, where all hospitalizations were precipitated by acute bleeding events, necessitating urgent intervention. Conclusions: Recombinant Factor VIII demonstrates superior efficacy in managing Hemophilia A in children compared to Cryoprecipitate. Recombinant therapy provides better clinical outcomes, justifying its use in modern treatment protocols.

Backyard flock sampling and artificial intelligence: A dual strategy for early detection of Avian Influenza and Newcastle Disease

Avian Influenza (AI) and Newcastle Disease (ND) are significant avian diseases that pose substantial threats to the commercial poultry industry due to their high contagion rates and potential for severe outcomes. Recent shifts in the epidemiology and ecology of both viruses have led to devastating impacts on wild bird and poultry populations, as well as farms and communities worldwide. These challenges underscore the necessity for One Health approaches to pandemic prevention and preparedness, emphasizing the need for multisectoral collaboration among animal, environmental, and public health sectors. To mitigate future pandemic risks, it is essential to control the transmission of AI and ND viruses among domestic and wild animals as well as humans. This involves addressing the upstream drivers of outbreaks, ensuring rapid response mechanisms, and conducting thorough risk assessments for zoonotic diseases. Effective implementation and maintenance of prevention programs, surveillance, and outbreak responses require strong political commitment and sustainable funding. A robust combination of active and passive surveillance strategies should be applied to monitor and control them. In addition, the integration of modern technologies, such as artificial intelligence and big data analytics, can enhance both active and passive surveillance efforts by improving the accuracy and speed of data collection, analysis, and reporting. The use of backyard flocks as an early warning system for avian diseases represents a proactive approach to understanding and managing the risks associated with AI and ND through targeted surveillance and timely interventions. In response to these challenges, the EpirORNIS Project aimed to leverage these sentinel backyard flocks for early detection of AI and ND, thereby enhancing surveillance and control strategies.

Monitoring of mosquito breeding sites in the municipality of Cascais, Portugal

Abstract Culex pipiens is the primary West Nile Virus vector in Portugal. Additionally, in 2017, Aedes albopictus, vector of various arboviruses, was detected in Northern Portugal. To mitigate viral transmission risks, effective surveillance is crucial, including monitoring egg, larva, and pupa stages. Located on the west of Lisbon, Cascais implemented a surveillance based on monitoring invasive species at Points of Entry and, complementarily, on detecting and intervening in breeding sites. Active searches for new breeding sites and monitoring those that were already identified are conducted weekly during the peak mosquito season (May to October) and biweekly during the colder season (November to April), following the methodology outlined below: • Upon detection, samples of immature stages are collected for submission to the National Institute of Health (INSA); • Corrective measures are requested to the managing entities of the locations where the sites are found; • Date of action, location, collection point, date of report, and status (pending or intervened) are recorded on a database; • Locations with pending status undergo continuous monitoring. In 2023, 16 artificial breeding sites were identified. These findings resulted from 23 actions conducted across 8 locations. 35 samples of immatures were collected, followed by their submission and notification to the respective managing entities. Recurrent detections were noted in 9 breeding sites. The managing entities implemented measures at 13 of the identified sites, leaving 3 with pending intervention. The identification of breeding sites demands continuous monitoring efforts and requires an effective coordination between the Public Health services and the management entities. Based on the achieved outcomes, it is evident that the implementation of corrective measures has been successful, making a significant contribution to reducing mosquito density. Key messages • Effective surveillance and intervention strategies are crucial in mitigating West Nile Virus and arbovirus transmission risks in Portugal. • Continuous monitoring and coordination between public health services and management entities are key for maintaining effective vector control measures.

SARS-CoV-2 variants induce increased inflammatory gene expression but reduced interferon responses and heme synthesis as compared with wild type strains

SARS-CoV-2 variants of concern (VOC) have been associated with increased viral transmission and disease severity. We investigated the mechanisms of pathogenesis caused by variants using a host blood transcriptome profiling approach. We analysed transcriptional signatures of COVID-19 patients comparing those infected with wildtype (wt), alpha, delta or omicron strains seeking insights into infection in Asymptomatic cases.Comparison of transcriptional profiles of Symptomatic and Asymptomatic COVID-19 cases showed increased differentially regulated gene (DEGs) of inflammatory, apoptosis and blood coagulation pathways, with decreased T cell and Interferon stimulated genes (ISG) activation. Between SARS-CoV-2 strains, an increasing number of DEGs occurred in comparisons between wt and alpha (196), delta (1425) or, omicron (2313) infections. COVID-19 cases with alpha or, delta variants demonstrated suppression transcripts of innate immune pathways. EGR1 and CXCL8 were highly upregulated in those infected with VOC; heme biosynthetic pathway genes (ALAS2, HBB, HBG1, HBD9) and ISGs were downregulated. Delta and omicron infections upregulated ribosomal pathways, reflecting increased viral RNA translation. Asymptomatic COVID-19 cases infected with delta infections showed increased cytokines and ISGs expression. Overall, increased inflammation, with reduced host heme synthesis was associated with infections caused by VOC infections, with raised type I interferon in cases with less severe disease.

Characterization of the viral genome of Omicron variants of SARS-CoV-2 circulating in Tripura, a remote frontier state in Northeastern India.

From 2020, with advent of COVID-19 pandemic, Tripura has experienced SARS-CoV-2 viral evolution in accordance with other parts of India. Since January 2022, the Omicron variant of SARS-CoV-2 virus became the predominant lineage circulating in India and neighboring countries. This study characterizes the viral genome of the omicron variant circulating in the state since its inception to June, 2023. The current study was performed on nasopharyngeal and oropharyngeal samples received from the various departments of AGMC, as well as eight district hospitals from Tripura. The positive samples with a cycle threshold value of 25 or less for the E and/or N gene were considered for whole genome sequencing using Illumina Miseq NGS platform. Majority of the sequences belonged to Clade 21L, with BA.5.2 being the major sub variant detected during the study period. Majority of the mutations were detected in the Spike protein region, including L24-, P25-, P26-, V213G, G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, S477N, T478K, Q498R, Y505H, Q954H and N969K. All the sequences uniquely showed the mutations A27S and G142D in N terminal domain in Spike protein, not being reported from other Indian sequences like BA.5 variants. T9I, A63T and P13L were major substitutions in E, M and N protein regions respectively. Escape of mutants from vaccine induced immunity was mostly observed in BA.2 sub variants, majority endowed with the triplet mutation of K417N + E484K + N501Y. The current study indicates that Omicron variants circulating in the state of Tripura is comparable to other regions of India and the neighbouring country of Bangladesh. Genetic mutations increasing viral transmissibility have been identified in the circulating viral genomes.

Effect of climate change on West Nile virus transmission in Italy: a systematic review

Abstract Background West Nile Virus (WNV) is a pathogen transmitted by mosquitoes of the Culex genus, affecting both humans and animals such as horses and birds. The prevalence of WNV infection has increased dramatically in recent years in Europe, especially in Italy, and has been related to climate and environmental changes linked to global warming. Our review aims to assess the relation between the spread of WNV in Italy and the different climate change-related factors. Methods We conducted a literature search in the PubMed, Web of Science, Embase and Scopus databases, actualised as of 20 February 2024, using as search terms WNV, its vectors and climate change, and limiting our analysis to studies conducted in to avoid an overly heterogeneous setting. We registered the review in PROSPERO (CRD42023430636). Results Of the 252 unique records retrieved, we eventually included 25 articles after full-text screening. These studies were published between 2011 and 2023 and evaluated the distribution of WNV or its vectors according to various climatic and environmental factors. Despite rather heterogeneous results, we found a consistently positive association with temperature, especially spring temperature, agricultural land use, demography, and soil moisture, and a negative one with evapotranspiration and wind, while the relationship with other environmental variables and water cycle-related factors was weak, null or conflicting. Conclusions Despite some inconsistencies in the results, likely related to differences in study methodologies as well as complex environmental interactions, we found unequivocal evidence that climate change-related factors, such as the lengthening of the warm season, extensive farming, and invasive human activities towards natural environments, favour WNV spread in Italy. Consequently, actions against global warming and preservation of natural environments may counteract the WNV epidemic. Key messages • WNV epidemic seems to be linked to specific climate change-related factors, such as the lengthening of the warm season, extensive farming, and invasive human activities towards natural environments. • Actions against global warming and preservation of natural environments may counteract WNV spread.

Obesity's Unexpected Influence: Reduced Alphavirus Transmission and Altered Immune Activation in the Vector.

Chikungunya virus (CHIKV) and Mayaro virus (MAYV) are emerging/re-emerging alphaviruses transmitted by Aedes spp. mosquitoes and responsible for recent disease outbreaks in the Americas. The capacity of these viruses to cause epidemics is frequently associated with increased mosquito transmission, which in turn is governed by virus-host-vector interactions. Although many studies have explored virus-vector interactions, significant gaps remain in understanding how vertebrate host factors influence alphavirus transmission by mosquitoes. We previously showed that obesity, a ubiquitous vertebrate host biological factor, reduces alphavirus transmission potential in mosquitoes. We hypothesized that alphavirus-infected obese bloodmeals altered immune genes and/or pathways in mosquitoes, thereby inhibiting virus transmission. To test this, we conducted RNA sequencing (RNA-seq) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) on midgut RNA from mosquitoes fed on alphavirus-infected lean and obese mice. This approach aimed to identify potential antiviral or proviral genes and pathways altered in mosquitoes after consuming infected obese bloodmeals. We found upregulation of the Toll pathway and downregulation of several metabolic and other genes in mosquitoes fed on alphavirus-infected obese bloodmeals. Through gene knockdown studies, we demonstrated the antiviral role of Toll pathway and proviral roles of AAEL009965 and fatty acid synthase (FASN) in the transmission of alphaviruses by mosquitoes. Therefore, this study utilized obesity to identify factors influencing alphavirus transmission by mosquitoes and this research approach may pave the way for designing broadly effective antiviral measures to combat mosquito-borne viruses, such as releasing transgenic mosquitoes deficient in the identified genes.

Healthcare access for people with disabilities: a scoping review of COVID-19 policies in Europe

Abstract Introduction The COVID-19 pandemic raised healthcare inequalities, affecting the most vulnerable groups. There is limited evidence of whether the COVID-19 measures and the health system’s preparedness for outbreaks among European countries were sufficient to cover the health access needs of PWDs. Aim To provide a structured overview of the COVID-19 measures and policies addressing access to primary and specialist health services for PWDs during the COVID-19 pandemic in the European Members States (MS) and the United Kingdom (UK), using ten dimensions of healthcare access by Levesque et al. (2013) and the PoliMap taxonomy. Methods This study followed the PRISMA guidelines for Scoping Reviews. A search strategy was employed on PubMed, Embase, Scopus, and Web of Science databases from January 2020 to January 2023. Studies published in peer-reviewed journals in English, Portuguese, and Spanish were included, informing a COVID-19 measure or policy and assessing or providing a rationale with access to primary or special healthcare services. Results The final search strategy yielded 2.076 results, 188 studies were reviewed for full-text analysis, and 74 were included in the final analysis. One hundred twenty-one policies or measures addressing primary or specialist care access were identified. Only thirteen target PWDs, focussing on intellectual or mental disability and addressing mental healthcare services. Results revealed that COVID-19 measures for PWDs were oriented to increase health system response capacity and reduce virus transmission, describing a predominantly negative effect on healthcare access for PWDs. Conclusions The needs of PWDs in access to primary and specialist care were not fully covered by the policies and measures placed during the COVID-19 pandemic among the MS and the UK. One-size approaches focussing on the attendance of COVID-19 infection with stigmatizing measures overlook the specific health necessities of this population. Key messages • Adopting disabled-inclusive measures in the daily healthcare provision and engaging PWDs in the policy cycle is paramount to preparing for the next outbreak and public health crises. • Additional research focusing on primary and specialized healthcare access during outbreaks for PWDs, especially with sensory and physical disabilities, is crucial to furthering health equity.

Statistical analysis of seroprevalence and risk factors of hepatitis C in Nowshera District, Pakistan

Hepatitis C virus (HCV) transmission remains a significant public health concern. It is well documented globally, however, Nowshera district, Pakistan, is lacking such profile. This study aims to explore the relationship between HCV infection and several risk factors, including socio-demographic, clinical and personal life-style factors. This study using a cross-sectional design, examined 606 randomly selected individuals visiting the Pathology department at Qazi Hussain Medical Complex and District Headquarter (DHQ) Hospital Nowshera between May 1, 2022 and Jun 30, 2023. This research investigation employed a methodical approach involving formal interviews in conjunction with structured questionnaires to gather comprehensive information related to socio-demographic characteristics, clinical history, and personal hygiene practices. We collected 10 ml of blood samples and tested the separated serum to identify markers using the Immuno-Chromatographic Test (ICT) and the Enzyme-Linked Immunosorbent Assay (ELISA). IBM SPSS Statistics version 27 was used for data analysis. To measure the association between dependent variable and independent variables, a chi-square and risk analysis was carried out; multiple logistic regression was employed for modeling the risk factors associated with independent variable. A statistical significance level was established at a P-value of less than 0.05. In present study, which included 606 participants, 12% were found to be infected with HCV. Importantly it revealed that facial shave at barber (adjusted odds ratio, aOR = 40.65, p = 0.000) represents the most prevalent mode of HCV transmission. Additionally, a strong association was observed between HCV infection and history of past surgery (RR = 2.98, p = 0.001), HCV infected family member (aOR = 4.28, p = 0.001), workplace injuries (aOR = 6.68, p = 0.000), history of hospital admission (RR = 2.09), practicing ear and nose piercing (aOR = 5.01, p = 0.001), dental treatment (RR = 2.31) and the frequency of injections (aOR = 8.607, p = 0.000). These findings underscore the pressing need for targeted interventions. This study highlights the paramount importance of understanding the modes of HCV transmission and their associated risk factors. The results emphasize the need for educational initiatives, both within the healthcare sector and among the general public, to combat HCV transmission effectively. By implementing sterilization procedures and increasing awareness, we can make significant strides in reducing the burden of HCV infection. Moreover, proactive measures within families can help contain the spread of the virus, ultimately contributing to improved public health.

Green Advances in Wet Finishing Methods and Nanoparticles for Daily Textiles.

This work presented an overview of greener technologies for realizing everyday fabrics with enhanced antibacterial activity, flame retardancy, water repellency, and UV protection. Traditional methods for improving these qualities in textiles involved dangerous chemicals, energy and water-intensive procedures, harmful emissions. New strategies are presented in response to the current emphasis on process and product sustainability. Nanoparticles (NPs) are suggested as a potential alternative for hazardous components in textile finishing. NPs are found to efficiently decrease virus transmission, limit combustion events, protect against UV radiation, and prevent water from entering, through a variety of mechanisms. Some attempts are made to increase NPs efficiency and promote long-term adherence to textile surfaces. Traditional wet finishing methods are implemented through a combination of advanced green technologies (plasma pre-treatment, ultrasound irradiations, sol-gel, and layer-by-layer self-assembly methods). The fibrous surface is activated by adding functional groups that facilitate NPs grafting on the textile substrate by basic interactions (chemical, physical, or electrostatic), also indirectly via crosslinkers, ligands, or coupling agents. Finally, other green options explore the use of NPs synthesized from bio-based materials or hybrid combinations, as well as inorganic NPs from green synthesis to realize ecofriendly finishing able to provide durable and protective fabrics.

Stress Can Induce Bovine Alpha-Herpesvirus 1 (BoHV-1) Reactivation from Latency

Bovine alpha-herpesvirus 1 (BoHV-1) is a significant problem for the cattle industry, in part because the virus establishes latency, and stressful stimuli increase the incidence of reactivation from latency. Sensory neurons in trigeminal ganglia and unknown cells in pharyngeal tonsils are importantsites for latency. Reactivation from latency can lead to reproductive problems in pregnant cows, virus transmission to young calves, suppression of immune responses, and bacterial pneumonia. BoHV-1 is also a significant cofactor in bovine respiratory disease (BRD). Stress, as mimicked by the synthetic corticosteroid dexamethasone, reproducibly initiates reactivation from latency. Stress-mediated activation of the glucocorticoid receptor (GR) stimulates viral replication and transactivation of viral promoters that drive the expression of infected cell protein 0 (bICP0) and bICP4. Notably, GR and Krüppel-like factor 15 (KLF15) form a feed-forward transcription loop that cooperatively transactivates immediate early transcription unit 1 (IEtu1 promoter). Two pioneer transcription factors, GR and KLF4, cooperatively transactivate the bICP0 early promoter. Pioneer transcription factors bind silent viral heterochromatin, remodel chromatin, and activate gene expression. Thus, wepredict that these novel transcription factors mediate early stages of BoHV-1 reactivation from latency.

Australian vertebrate hosts of Japanese encephalitis virus: a review of the evidence.

Japanese encephalitis virus (JEV) transmission in temperate Australia has underscored a critical need to characterise transmission pathways and identify probable hosts of the virus. This systematic review consolidates existing research on the vertebrate hosts of JEV that are known to exist in Australia. Specifically, we aim to identify probable species involved in JEV transmission, their potential role as hosts and identify critical knowledge gaps. Data were extracted from studies involving experimental infection, seroprevalence and virus isolation and were available for 22 vertebrate species known to reside in Australia. A host competence score was calculated to assess the ability of each species to generate and sustain a viraemia. Based on the host competence score and ecology of each species, we find that ardeid birds, feral pigs and flying foxes have potential as maintenance hosts for JEV in the Australian context. We also note that domestic pigs are frequently infected during outbreaks, but their role as amplification hosts in Australia is unclear. Evidence to confirm these roles is sparse, emphasising the need for further targeted research. This review provides a foundation for future investigations into JEV transmission in Australia, advocating for enhanced surveillance and standardised research methodologies to better understand and mitigate the virus's impact.

The Health and Economic Benefits of United States Investments in Measles and Rubella Control and Elimination

Background: Prior to measles vaccine introduction in 1963, measles virus caused hundreds of thousands of annual reported cases, which led to substantial US morbidity, mortality, and costs. Similarly, congenital rubella syndrome (CRS) led to highly visible and tragic lifelong disability for thousands of Americans, before rubella vaccine introduction in 1969. The US certified national virus transmission elimination of indigenous measles in 2000 and rubella in 2004. Methods: Applying an existing integrated transmission and economic model, this analysis characterizes the net benefits of US investments in measles (1963–2030) and rubella (1969–2030) immunization assuming continued high routine immunization coverage. Due to importation risks, the US maintains two doses of both vaccines in its routine immunization schedule. Results: This analysis estimates total US costs of 8.1 billion (economics reported in 2023 US dollars) for measles immunization for 1963–2023 and 14.1 billion for rubella immunization for 1969–2023. The analysis estimates an additional approximately 1.2 billion for measles immunization and 1.5 billion for rubella immunization expected for 2024–2030. Historical and future US investments prevented an estimated approximately 237 million measles infections, 228,000 measles deaths, 193 million rubella infections, and 166,000 CRS cases. These investments imply net benefits (from avoided treatment costs minus immunization costs) of approximately 310 billion for measles and 430 billion for rubella and CRS, even without incorporating avoided productivity losses and intangible costs. Conclusions: US investments in measles and rubella immunization continue to provide enormous savings of human and financial costs and to prevent substantial mortality and morbidity.

Emergence of ECSA-IOL E1-K211E/E2-V264A Lineage of Chikungunya virus during Malaysian 2021 outbreak

BackgroundChikungunya cases was reported to be on the rise in Malaysia from 2019 to 2021. Although potential endemicity was described previously, genotype shift during 2008 outbreak originating from the 2004 Indian Ocean Islands outbreak presents the probability of current CHIKV spread from neighboring countries. This is due to the prevalence of the new IOL sub-lineage which consists of E1-226A wildtype or reverted strains that are circulating in the Indian subcontinent before spreading to neighboring Thailand during 2018–2019 outbreak.MethodIn this study, samples received mostly from the Tangkak, Johor were analyzed. A total 56 CHIKV positive serum samples received in 2021 by Institute of Medical Research Malaysia (IMR), were collected based on sample selection criteria. Selected samples were subjected to total RNA extraction, whole-genome sequencing as well as bioinformatic analysis such as phylogenetic, variant and mutation analysis.ResultsBased on the genomic and phylogenetic analysis, the CHIKV samples from 2021 outbreak were of ECSA-IOL genotype. Genome similarity analysis also revealed that these CHIKVs were highly similar to 2018–2019 outbreak strain from Thailand. In comparison to the 2008 outbreak CHIKV isolate, the current CHIKVs lacked the E1-A226V mutation and harbored the new E1-K211E/E2-V264A sub-linage mutation. Since the E1-K211E/E2-V264A mutation facilitates adaptation to Ae. aegypti as opposed to the E1-A226V mutation which improves adaptation to Ae. albopictus, the emergence 2021 CHIKV outbreak in Malaysia can be postulated due to vector shift. Interestingly, a novel nsP3-T441A/V mutation detected in this study, may also play a role in virus transmission, pathogenicity, fitness and vector adaptation.ConclusionIn summary, the current CHIKV outbreak are strains originated from the Indian subcontinent through Thailand which may have capitalized on vector shifting by adapting to Ae. aegypti. The presence of novel nsP3-T441A/V mutation may also contribute to the spread of this virus across peninsular Malaysia.

Indirect and direct effects of nighttime light on COVID-19 mortality using satellite image mapping approach

The COVID-19 pandemic has highlighted the importance of understanding environmental factors in disease transmission. This study aims to explore the spatial association between nighttime light (NTL) from satellite imagery and COVID-19 mortality. It particularly examines how NTL serves as a pragmatic proxy to estimate human interaction in illuminated nocturnal area, thereby impacting viral transmission dynamics to neighboring areas, which is defined as spillover effect. Analyzing 43,199 COVID-19 deaths from national mortality data during January 2020 and October 2022, satellite-derived NTL data, and various environmental and socio-demographic covariates, we employed the Spatial Durbin Error Model to estimate the direct and indirect effect of NTL on COVID-19 mortality. Higher NTL was initially directly linked to increased COVID-19 mortality but this association diminished over time. The spillover effect also changed: during the early 3rd wave (December 2020 – February 2021), a unit (nanoWatts/sr/cm2) increase in NTL led to a 7.9% increase in neighboring area mortality (p = 0.013). In contrast, in the later 7th wave (July – September 2022), dominated by Omicron, a unit increase in NTL resulted in an 8.9% decrease in mortality in neighboring areas (p = 0.029). The shift from a positive to a negative spillover effect indicates a change in infection dynamics during the pandemic. The study provided a novel approach to assess nighttime human activity and its influence on disease transmission, offering insights for public health strategies utilizing satellite imagery, particularly when direct data collection is impractical while the collection from space is readily available.

Transcriptional Modulation of Plant Defense Genes by a Bipartite Begomovirus Promotes the Performance of Its Whitefly Vector

The majority of plant viruses rely on insect vectors for inter-plant transmission. Amid virus transmission, vector-borne viruses such as begomoviruses may significantly modulate host plants in various ways and, in turn, plant palatability to insect vectors. While many case studies on monopartite begomoviruses are available, bipartite begomoviruses are understudied. More importantly, detailed elucidation of the molecular mechanisms involved is limited. Here, we report the mechanisms by which an emerging bipartite begomovirus, the Sri Lankan cassava mosaic virus (SLCMV), modulates plant defenses against whitefly. SLCMV infection of tobacco (Nicotiana tabacum) plants significantly downregulated defenses against whitefly, as whitefly survival and fecundity increased significantly on virus-infected plants when compared to the controls. We then profiled SLCMV-induced transcriptomic changes in plants and identified a repertoire of differentially expressed genes (DEGs). GO enrichment analysis of DEGs demonstrated that the term defense response was significantly enriched. Functional analysis of DEGs associated with defense response revealed that four downregulated DEGs, including putative late blight resistance protein homolog R1B-17 (R1B-17), polygalacturonase inhibitor-like (PGI), serine/threonine protein kinase CDL1-like (CDL1), and Systemin B, directly contributed to plant defenses against whitefly. Taken together, our findings elucidate the role of novel plant factors involved in the modulation of plant defenses against whitefly by a bipartite begomovirus and shed new light on insect vector–virus–host plant tripartite interactions.