Emerging and Reemerging Infectious Diseases: Global Overview

Leptospira spp. and Rickettsia spp. as pathogens with zoonotic potential causing acute undifferentiated febrile illness in a central-eastern region of Peru

OBJETIVE

this study was to determine the relationship between acute febrile illness and bacterial pathogens with zoonotic potential that cause emerging and re-emerging diseases in a central-eastern region of Peru.

RESULTS

Out of the 279 samples analyzed, 23 (8.2%) tested positive for infection by Rickettsia spp., while a total of 15 (5.4%) tested positive for Leptospira spp. Women had a higher frequency of infection by Rickettsia spp., with 13 cases (53.3%), while men had a higher frequency of infection by Leptospira spp., with 10 cases (66.7%). The most frequently reported general symptom was headache, with 100.0% (n = 23) of patients with Rickettsia (+) and 86.7% (n = 13) of patients with Leptospira (+) experiencing it. Arthralgia was the second most frequent symptom, reported by 95.6% (n = 22) and 60% (n = 9) of patients with Rickettsia (+) and Leptospira (+), respectively. Myalgia was reported by 91.3% (n = 21) and 66.7% (n = 10) of patients with Rickettsia (+) and Leptospira (+), respectively. Retroocular pain, low back pain, and skin rash were also present, but less frequently. Among the positives, no manifestation of bleeding was recorded, although only one positive case for Leptospira spp. presented a decrease in the number of platelets.

Novel technologies are turning a dream into reality: conditionally replicating viruses as vaccines

Conditionally replicating viruses (CRVs) are a type of virus with one or more essential gene functions that are impaired resulting in the disruption of viral genome replication, protein synthesis, or virus particle assembly. CRVs can replicate only if the deficient essential genes are supplied. CRVs are widely used in biomedical research, particularly as vaccines. Traditionally, CRVs are generated by creating complementary cell lines that provide the impaired genes. With the development of biotechnology, novel techniques have been invented to generate CRVs, such as targeted protein degradation (TPD) technologies and premature termination codon (PTC) read-through technologies. The advantages and disadvantages of these novel technologies are discussed. Finally, we provide perspectives on what challenges need to be overcome for CRVs to reach the market.

Phenotypic and molecular characterization and complete genome sequence of a Corynebacterium diphtheriae strain isolated from cutaneous infection in an immunized individual

Diphtheria is an infectious disease potentially fatal that constitutes a threat to global health security, with possible local and systemic manifestations that result mainly from the production of diphtheria toxin (DT). In the present work, we report a case of infection by Corynebacterium diphtheriae in a cutaneous lesion of a fully immunized individual and provided an analysis of the complete genome of the isolate. The clinical isolate was first identified by MALDI-TOF Mass Spectrometry. The commercial strip system and mPCR performed phenotypic and genotypic characterization, respectively. The antimicrobial susceptibility profile was determined by the disk diffusion method. Additionally, genomic DNA was sequenced and analyzed for species confirmation and sequence type (ST) determination. Detection of resistance and virulence genes was performed by comparisons against ResFinder and VFDB databases. The isolate was identified as a nontoxigenic C. diphtheriae biovar Gravis strain. Its genome presented a size of 2.46 Mbp and a G + C content of 53.5%. Ribosomal Multilocus Sequence Typing (rMLST) allowed the confirmation of species as C. diphtheriae with 100% identity. DDH in silico corroborated this identification. Moreover, MLST analyses revealed that the isolate belongs to ST-536. No resistance genes were predicted or mutations detected in antimicrobial-related genes. On the other hand, virulence genes, mostly involved in iron uptake and adherence, were found. Presently, we provided sufficient clinical data regarding the C. diphtheriae cutaneous infection in addition to the phenotypic and genomic data of the isolate. Our results indicate a possible circulation of ST-536 in Brazil, causing cutaneous infection. Considering that cases of C. diphtheriae infections, as well as diphtheria outbreaks, have still been reported in several regions of the world, studies focusing on taxonomic analyzes and predictions of resistance genes may help to improve the diagnosis and to monitor the propagation of resistant clones. In addition, they can contribute to understanding the association between variation in genetic factors and resistance to antimicrobials.

Virus-specific and shared gene expression signatures in immune cells after vaccination in response to influenza and vaccinia stimulation

Background

In the vaccine era, individuals receive multiple vaccines in their lifetime. Host gene expression in response to antigenic stimulation is usually virus-specific; however, identifying shared pathways of host response across a wide spectrum of vaccine pathogens can shed light on the molecular mechanisms/components which can be targeted for the development of broad/universal therapeutics and vaccines.

Method

We isolated PBMCs, monocytes, B cells, and CD8+ T cells from the peripheral blood of healthy donors, who received both seasonal influenza vaccine (within <1 year) and smallpox vaccine (within 1 - 4 years). Each of the purified cell populations was stimulated with either influenza virus or vaccinia virus. Differentially expressed genes (DEGs) relative to unstimulated controls were identified for each in vitro viral infection, as well as for both viral infections (shared DEGs). Pathway enrichment analysis was performed to associate identified DEGs with KEGG/biological pathways.

Results

We identified 2,906, 3,888, 681, and 446 DEGs in PBMCs, monocytes, B cells, and CD8+ T cells, respectively, in response to influenza stimulation. Meanwhile, 97, 120, 20, and 10 DEGs were identified as gene signatures in PBMCs, monocytes, B cells, and CD8+ T cells, respectively, upon vaccinia stimulation. The majority of DEGs identified in PBMCs were also found in monocytes after either viral stimulation. Of the virus-specific DEGs, 55, 63, and 9 DEGs occurred in common in PBMCs, monocytes, and B cells, respectively, while no DEGs were shared in infected CD8+ T cells after influenza and vaccinia. Gene set enrichment analysis demonstrated that these shared DEGs were over-represented in innate signaling pathways, including cytokine-cytokine receptor interaction, viral protein interaction with cytokine and cytokine receptor, Toll-like receptor signaling, RIG-I-like receptor signaling pathways, cytosolic DNA-sensing pathways, and natural killer cell mediated cytotoxicity.

Conclusion

Our results provide insights into virus-host interactions in different immune cells, as well as host defense mechanisms against viral stimulation. Our data also highlights the role of monocytes as a major cell population driving gene expression in ex vivo PBMCs in response to viral stimulation. The immune response signaling pathways identified in this study may provide specific targets for the development of novel virus-specific therapeutics and improved vaccines for vaccinia and influenza. Although influenza and vaccinia viruses have been selected in this study as pathogen models, this approach could be applicable to other pathogens.

Leveraging Responsible, Explainable, and Local Artificial Intelligence Solutions for Clinical Public Health in the Global South

In the present paper, we will explore how artificial intelligence (AI) and big data analytics (BDA) can help address clinical public and global health needs in the Global South, leveraging and capitalizing on our experience with the "Africa-Canada Artificial Intelligence and Data Innovation Consortium" (ACADIC) Project in the Global South, and focusing on the ethical and regulatory challenges we had to face. "Clinical public health" can be defined as an interdisciplinary field, at the intersection of clinical medicine and public health, whilst "clinical global health" is the practice of clinical public health with a special focus on health issue management in resource-limited settings and contexts, including the Global South. As such, clinical public and global health represent vital approaches, instrumental in (i) applying a community/population perspective to clinical practice as well as a clinical lens to community/population health, (ii) identifying health needs both at the individual and community/population levels, (iii) systematically addressing the determinants of health, including the social and structural ones, (iv) reaching the goals of population's health and well-being, especially of socially vulnerable, underserved communities, (v) better coordinating and integrating the delivery of healthcare provisions, (vi) strengthening health promotion, health protection, and health equity, and (vii) closing gender inequality and other (ethnic and socio-economic) disparities and gaps. Clinical public and global health are called to respond to the more pressing healthcare needs and challenges of our contemporary society, for which AI and BDA can help unlock new options and perspectives. In the aftermath of the still ongoing COVID-19 pandemic, the future trend of AI and BDA in the healthcare field will be devoted to building a more healthy, resilient society, able to face several challenges arising from globally networked hyper-risks, including ageing, multimorbidity, chronic disease accumulation, and climate change.

Characterization of anti-erythrocyte and anti-platelet antibodies in hemolytic anemia and thrombocytopenia induced by Plasmodium spp. and Babesiaspp. infection in mice

Introduction

Malaria and Babesiosis are acute zoonotic disease that caused by infection with the parasite in the phylum Apicomplexa. Severe anemia and thrombocytopenia are the most common hematological complication of malaria and babesiosis. However, the mechanisms involved have not been elucidated, and only a few researches focus on the possible role of anti-erythrocyte and anti-platelet antibodies.

Methods

In this study, the Plasmodium yoelii, P. chabaudi, Babesia microti and B. rodhaini infected SCID and ICR mice. The parasitemia, survival rate, platelet count, anti-platelet antibodies, and the level of IFN-γ and interleukin (IL) -10 was tested after infection. Furthermore, the P. yoelii, P. chabaudi, B. rodhaini and B. microti infected ICR mice were treated with artesunate and diminaze, the development of the anti-erythrocyte and anti-platelet antibodies in chronic stage were examined. At last, the murine red blood cell and platelet membrane proteins probed with auto-antibodies induced by P. yoelii, P. chabaudi, B. rodhaini, and B. microti infection were characterized by proteomic analysis.

Results and discussion

The high anti-platelet and anti-erythrocyte antibodies were detected in ICR mice after P. yoelii, P. chabaudi, B. rodhaini, and B. microti infection. Actin of murine erythrocyte and platelet is a common auto-antigen in Plasmodium and Babesia spp. infected mice. Our findings indicate that anti-erythrocyte and anti-platelet autoantibodies contribute to thrombocytopenia and anemia associated with Plasmodium spp. and Babesia spp. infection. This study will help to understand the mechanisms of malaria and babesiosis-related thrombocytopenia and hemolytic anemia.

Evidence of Antimicrobial Resistance in Bats and Its Planetary Health Impact for Surveillance of Zoonotic Spillover Events: A Scoping Review

As a result of the COVID-19 pandemic, as well as other outbreaks, such as SARS and Ebola, bats are recognized as a critical species for mediating zoonotic infectious disease spillover events. While there is a growing concern of increased antimicrobial resistance (AMR) globally during this pandemic, knowledge of AMR circulating between bats and humans is limited. In this paper, we have reviewed the evidence of AMR in bats and discussed the planetary health aspect of AMR to elucidate how this is associated with the emergence, spread, and persistence of AMR at the human-animal interface. The presence of clinically significant resistant bacteria in bats and wildlife has important implications for zoonotic pandemic surveillance, disease transmission, and treatment modalities. We searched MEDLINE through PubMed and Google Scholar to retrieve relevant studies (n = 38) that provided data on resistant bacteria in bats prior to 30 September 2022. There is substantial variability in the results from studies measuring the prevalence of AMR based on geographic location, bat types, and time. We found all major groups of Gram-positive and Gram-negative bacteria in bats, which are resistant to commonly used antibiotics. The most alarming issue is that recent studies have increasingly identified clinically significant multi-drug resistant bacteria such as Methicillin Resistant Staphylococcus aureus (MRSA), ESBL producing, and Colistin resistant Enterobacterales in samples from bats. This evidence of superbugs abundant in both humans and wild mammals, such as bats, could facilitate a greater understanding of which specific pathways of exposure should be targeted. We believe that these data will also facilitate future pandemic preparedness as well as global AMR containment during pandemic events and beyond.

CRISPR-Cas in Diagnostics and Therapy of Infectious Diseases

Infectious diseases are a major threat to the global health. The rise in antimicrobial-resistant organisms, incurable chronic infections, and an increasing demand for rapid accurate diagnostics have prompted researchers to experiment with new approaches. Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) is a naturally occurring adaptive immune system in bacteria that has been developed as a tool for performing genomic alterations in any genome of interest, including humans and microbes. Accordingly, several studies have been conducted to investigate how the technology can be utilized in infectious diseases to improve diagnostics, disrupt antimicrobial resistance, and cure chronic infections. This review provides an overview of the CRISPR-Cas system and how it has been applied in studies on infectious diseases. The review also investigates the current challenges of the technology and the improvements that are needed for the platform to be adopted for clinical use in patients.

Providing On-Site Laboratory and Biosafety Just-In-Time Training Inside a Box-Based Laboratory during the West Africa Ebola Outbreak: Supporting Better Preparedness for Future Health Emergencies

The Biological Light Fieldable Laboratory for Emergencies (B-LiFE) is a box-based modular laboratory with the capacity to quickly deploy on-site in cases of uncontrolled spread of infectious disease. During the 2014-2015 West Africa Ebola outbreak, this tent laboratory provided diagnostic support to the N'Zerekore Ebola Treatment Center (ETC), Guinea, for three months. One of the objectives of B-LiFE deployment was to contribute, as much as possible, to national capacity building by training local scientists. Two Guinean biologists were selected according to their basic biological knowledge and laboratory skills among 50 candidate trainees, and were integrated into the team through "just-in-time training" (JiTT), which helped the biologists acquire knowledge and laboratory skills beyond their expertise. The JiTT program was conducted according to standard laboratory procedures, in line with international biosafety guidelines adapted to field conditions. Supervised acquisition of field-laboratory practices mainly focused on biochemical testing and Ebola viral load quantification using routine PCR-based detection, including the Biofire FilmArray^® system (BFA), a novel, as yet non-validated, automated assay for diagnostic testing of Ebola virus disease at the time of B-LiFE deployment. During the JiTT, the two biologists were closely involved in all laboratory activities, including BFA validation and biosafety procedures. Meanwhile, this successful JiTT enhanced the B-LiFE in-field operational capacity and contributed to national capacity building. A post-training evaluation and contacts were organised to assess the evolution and technical skills gained by the two researchers during the B-LiFE mission. At the end of the B-LiFE mission, both biologists were enrolled in follow-on programmes to curb the epidemic spreading in Africa. These results demonstrate that during infectious disease outbreaks or major crises, the JiTT approach can rapidly expand access to critical diagnostic testing and train local staff to do so.

Systematic review on ensuring the global food security and covid-19 pandemic resilient food systems: towards accomplishing sustainable development goals targets

Covid-19, one of the most critical and widespread global pandemics, has resulted in extraordinary risk corollaries engulfing millions of people's lives and has caused an unprecedented economic downturn while amplifying food insecurity. A systematic review of 132 scientific communications was performed over a 15-year period, using articles from the ScienceDirect and Web of Science databases (2006-2021). In addition, 24 policy briefs, country papers, and publications from the UN, WHO, FAO, and OECD were cited. The aim of this paper is to provide a comprehensive review of existing literature on the adverse effects of the Covid-19 pandemic on agricultural food systems, as well as potential strategies for building robust, resilient, and sustainable food systems to ensure global food security, safety, and endeavors regarding future global emergencies, as well as new research policies while achieving SDG targets. This would fill a research gap while also having long-term implications for health, agricultural, and food resilience policy development in a rapidly changing world. Covid-19 demonstrates how human, animal, and environmental health are all interconnected, emphasizing the need for one health legislation and a paradigm shift in planetary health. Furthermore, it identifies potential mechanisms for rebuilding better systems by shifting priorities toward policy coherence, innovative food system governance, re-engineering market access, and nexus thinking in the food system approach. According to our findings, the COVID-19 posed unavoidable impediments to achieving SDG targets for food security and household poverty.

Graphical abstract

‘Live with the Virus’ Narrative and Pandemic Amnesia in the Governance of COVID-19

Political leaders have commonly used the phrase ‘learn to live with the virus’ to explain to citizens how they should respond to the COVID-19 pandemic. I consider how the ‘live with the virus’ narrative perpetrates pandemic amnesia by refusing what is known about pandemic-related inequities and the strategies that can be used to overcome these effects. Advice to ‘live with the virus’ helps to further austerity public policy and therefore individualises the social and health burdens of post pandemic life. ‘Live with the virus’ asks citizens to look only to their own futures, which are political strategies that might work for privileged individuals who have the capacity to protect their health, but less well for those with limited personal resources. I draw on Esposito’s framing of affirmative biopolitics and scholarship on how excluded communities have built for themselves health-sustaining commons in responses to pandemic threats to health. I argue that creating opportunities for a ‘COVID-19 commons’ that can enlarge capacity for citizenly deliberation on how they have been governed and other pandemic related matters is vital for the development of more ethical and equitable post-pandemic politics.

Development of a Monoclonal Antibody to a Vibriophage as a Proxy for Vibrio cholerae Detection

Cholera is an acute watery, diarrheal disease that causes high rates of morbidity and mortality without treatment. Early detection of the etiologic agent of toxigenic Vibrio cholerae is important to mobilize treatment and mitigate outbreaks. Monoclonal antibody (mAb) based rapid diagnostic tests (RDTs) enable early detection in settings without laboratory capacity. However, the odds of an RDT testing positive are reduced by nearly 90% when the common virulent bacteriophage ICP1 is present. We hypothesize that adding a mAb for the common, and specific, virulent bacteriophage ICP1 as a proxy for V. cholerae to an RDT will increase diagnostic sensitivity when virulent ICP1 phage is present. In this study, we used an in-silico approach to identify immunogenic ICP1 protein targets that were conserved across disparate time periods and locations. Specificity of targets to cholera patients with known ICP1 was determined, and specific targets were used to produce mAbs in a murine model. Candidate mAbs to the head protein demonstrated specificity to ICP1 by Enzyme linked immunosorbent assay (ELISA) and an ICP1 phage neutralization assay. The limit of detection of the final mAb candidate for ICP1 phage particles spiked into cholera stool matrix was 8 × 10⁵ PFU by Western blotting analysis. This mAb will be incorporated into a RDT prototype for evaluation in a future diagnostic study to test the guiding hypothesis behind this study.

Viral haemorrhagic fevers and malaria co-infections among febrile patients seeking health care in Tanzania

Background

In recent years there have been reports of viral haemorrhagic fever (VHF) epidemics in sub-Saharan Africa where malaria is endemic. VHF and malaria have overlapping clinical presentations making differential diagnosis a challenge. The objective of this study was to determine the prevalence of selected zoonotic VHFs and malaria co-infections among febrile patients seeking health care in Tanzania.

Methods

This facility-based cross-sectional study was carried out between June and November 2018 in Buhigwe, Kalambo, Kyela, Kilindi, Kinondoni, Kondoa, Mvomero, and Ukerewe districts in Tanzania. The study involved febrile patients seeking health care from primary healthcare facilities. Blood samples were collected and tested for infections due to malaria, Crimean-Congo haemorrhagic fever (CCHF), Ebola virus disease (EVD), Marburg virus disease (MVD), Rift Valley fever (RVF) and yellow fever (YF). Malaria infections were tested using rapid diagnostics tests while exposure to VHFs was determined by screening for immunoglobulin M antibodies using commercial enzyme-linked immunosorbent assays. The Chi-square test was used to compare the proportions.

Results

A total of 308 participants (mean age = 35 ± 19 years) were involved in the study. Of these, 54 (17.5%) had malaria infection and 15 (4.8%) were positive for IgM antibodies against VHFs (RVF = 8; CCHF = 2; EBV = 3; MBV = 1; YF = 1). Six (1.9%) individuals had both VHF (RVF = 2; CCHF = 1; EVD = 2; MVD = 1) and malaria infections. The highest co-infection prevalence (0.6%) was observed among individuals aged 46‒60 years (P < 0.05). District was significantly associated with co-infection (P < 0.05) with the highest prevalence recorded in Buhigwe (1.2%) followed by Kinondoni (0.9%) districts. Headache (100%) and muscle, bone, back and joint pains (83.3%) were the most significant complaints among those infected with both VHFs and malaria (P = 0.001).

Conclusions

Co-infections of VHF and malaria are prevalent in Tanzania and affect more the older than the younger population. Since the overlapping symptoms in co-infected individuals may challenge accurate diagnosis, adequate laboratory diagnosis should be emphasized in the management of febrile illnesses.

Antiviral Peptides (AVPs) of Marine Origin as Propitious Therapeutic Drug Candidates for the Treatment of Human Viruses

The marine environment presents a favorable avenue for potential therapeutic agents as a reservoir of new bioactive natural products. Due to their numerous potential pharmacological effects, marine-derived natural products—particularly marine peptides—have gained considerable attention. These peptides have shown a broad spectrum of biological functions, such as antimicrobial, antiviral, cytotoxic, immunomodulatory, and analgesic effects. The emergence of new virus strains and viral resistance leads to continuing efforts to develop more effective antiviral drugs. Interestingly, antimicrobial peptides (AMPs) that possess antiviral properties and are alternatively regarded as antiviral peptides (AVPs) demonstrate vast potential as alternative peptide-based drug candidates available for viral infection treatments. Hence, AVPs obtained from various marine organisms have been evaluated. This brief review features recent updates of marine-derived AVPs from 2011 to 2021. Moreover, the biosynthesis of this class of compounds and their possible mechanisms of action are also discussed. Selected peptides from various marine organisms possessing antiviral activities against important human viruses—such as human immunodeficiency viruses, herpes simplex viruses, influenza viruses, hepatitis C virus, and coronaviruses—are highlighted herein.

Ecological Barrier Deterioration Driven by Human Activities Poses Fatal Threats to Public Health due to Emerging Infectious Diseases

The coronavirus disease 2019 (COVID-19) and concerns about several other pandemics in the 21st century have attracted extensive global attention. These emerging infectious diseases threaten global public health and raise urgent studies on unraveling the underlying mechanisms of their transmission from animals to humans. Although numerous works have intensively discussed the cross-species and endemic barriers to the occurrence and spread of emerging infectious diseases, both types of barriers play synergistic roles in wildlife habitats. Thus far, there is still a lack of a complete understanding of viral diffusion, migration, and transmission in ecosystems from a macro perspective. In this review, we conceptualize the ecological barrier that represents the combined effects of cross-species and endemic barriers for either the natural or intermediate hosts of viruses. We comprehensively discuss the key influential factors affecting the ecological barrier against viral transmission from virus hosts in their natural habitats into human society, including transmission routes, contact probability, contact frequency, and viral characteristics. Considering the significant impacts of human activities and global industrialization on the strength of the ecological barrier, ecological barrier deterioration driven by human activities is critically analyzed for potential mechanisms. Global climate change can trigger and expand the range of emerging infectious diseases, and human disturbances promote higher contact frequency and greater transmission possibility. In addition, globalization drives more transmission routes and produces new high-risk regions in city areas. This review aims to provide a new concept for and comprehensive evidence of the ecological barrier blocking the transmission and spread of emerging infectious diseases. It also offers new insights into potential strategies to protect the ecological barrier and reduce the wide-ranging risks of emerging infectious diseases to public health.

Influence of Religiosity and Spirituality on the Adoption of Behaviors of Epidemiological Relevance in Emerging and Re-Emerging Diseases: The Case of Dengue Fever

Emerging and re-emerging diseases are responsible for recurrently affecting the health of human populations. Although people are aware of these diseases, they do not seem to adopt prophylactic methods to prevent them. Here, we propose to investigate the influence of religiosity/spirituality (R/S) on the frequency of the adoption of prophylactic behaviors and the perception of risk of vulnerability to the disease. We used dengue, which is a seasonal arboviral disease in Brazil, as a model. To measure the dimensions of religiosity/spirituality, we used the Portuguese version of the Brief Multidimensional Measure of Religiosity/Spirituality questionnaire. All data were obtained through a structured questionnaire that was answered online by 204 volunteers living throughout Brazil. Our results indicate that R/S is predictive of the frequency of prophylactic behaviors (p = 0.0222, R² = 0.025) and the perception of risk of vulnerability (p < 0.05, R² = 0.07). We argue that the effect of R/S on health occurs through the promotion of salutogenic mechanisms promoted by socialization in religious environments. This can help understand social dynamics in epidemiological crises and mitigate the influence of these diseases.

Evidence of TB Services at Primary Healthcare Level during COVID-19: A Scoping Review

Tuberculosis (TB) is still a major public health concern, despite the availability of preventative and curative therapies. Significant progress has been made in the past decade towards its control. However, the emergence of the novel coronavirus disease 2019 (COVID-19) has disrupted numerous essential health services, including those for TB. This scoping review maps the available evidence on TB services at the primary healthcare (PHC) level during the COVID-19 period. A comprehensive literature search was conducted in PubMed, Web of Science, Medline OVID, Medline EBSCO, and Scopus. A total of 820 articles were retrieved from the databases and 21 met the eligibility criteria and were used for data extraction. The emerging themes were the effect of the COVID-19 pandemic on TB services, patient and provider experiences, recommendations for TB services during the COVID-19 period, and the implementation of the recommendations. The review found that the mitigation strategies, as well as fear and stigma experienced at the start of the COVID-19 pandemic may have led to TB cases potentially going undetected, which may threaten TB treatment outcomes. Therefore, efforts must be directed at finding these missing cases and ensuring that PHC facilities are equipped to adequately diagnose and treat them.

Research progress of epigallocatechin-3-gallate (EGCG) on anti-pathogenic microbes and immune regulation activities

At the end of 2019, the COVID-19 virus spread worldwide, infecting millions of people. Infectious diseases induced by pathogenic microorganisms such as the influenza virus, hepatitis virus, and Mycobacterium tuberculosis are also a major threat to public health. The high mortality caused by infectious pathogenic microorganisms is due to their strong virulence, which leads to the excessive counterattack by the host immune system and severe inflammatory damage of the immune system. This paper reviews the efficacy, mechanism and related immune regulation of epigallocatechin-3-gallate (EGCG) as an anti-pathogenic microorganism drug. EGCG mainly shows both direct and indirect anti-infection effects. EGCG directly inhibits early infection by interfering with the adsorption on host cells, inhibiting virus replication and reducing bacterial biofilm formation and toxin release; EGCG indirectly inhibits infection by regulating immune inflammation and antioxidation. At the same time, we reviewed the bioavailability and safety of EGCG in vivo. At present, the bioavailability of EGCG can be improved to some extent using nanostructured drug delivery systems and molecular modification technology in combination with other drugs. This study provides a theoretical basis for the development of EGCG as an adjuvant drug for anti-pathogenic microorganisms.

Emerging and Re-Emerging Diseases

Throughout history, infectious diseases have vastly impacted human civilization [...].

Nipah virus: a potential pandemic agent in the context of the current severe acute respiratory syndrome coronavirus 2 pandemic

For centuries, zoonotic diseases have been responsible for various outbreaks resulting in the deaths of millions of people. The best example of this is the current coronavirus disease 2019 (COVID-19) pandemic. Like severe acute respiratory syndrome coronavirus, Nipah virus is another deadly virus which has caused several outbreaks in the last few years. Though it causes a low number of infections, disease severity results in a higher death rate. In the context of the recent COVID-19 pandemic, we speculate that many countries will be unable to deal with the sudden onset of such a viral outbreak. Thus, further research and attention to the virus are needed to address future outbreaks.

Peptide-Based Antiviral Drugs

Three types of chemical entities, namely, small organic molecules (organics), peptides, and biologics, are mainly used as drug candidates for the treatment of various diseases. Even though the peptide drugs are known since 1920 in association with the clinical use of insulin, only a limited number of peptides are currently used for therapeutics due to various disadvantages associated with them such as limited serum and blood stability, oral bioavailability, and permeability. Since, through chemical modifications and structure tuning, many of these limitations can be overcome, peptide-based drugs are gaining attention in pharmaceutical research. As of today, there are more than 60 peptide-based drugs approved by FDA, and over 150 peptides are in the advanced clinical studies. In this book chapter, the peptide-based lead compounds and drugs available for treating various viral diseases and their advantages and disadvantages when compared to small molecules drugs are discussed.

A domain-based vaccine construct against SARS-CoV-2, the causative agent of COVID-19 pandemic: development of self-amplifying mRNA and peptide vaccines

Introduction: Coronavirus disease 2019 (COVID-19) is undoubtedly the most challenging pandemic in the current century with more than 293,241 deaths worldwide since its emergence in late 2019 (updated May 13, 2020). COVID-19 is caused by a novel emerged coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Today, the world needs crucially to develop a prophylactic vaccine scheme for such emerged and emerging infectious pathogens. Methods: In this study, we have targeted spike (S) glycoprotein, as an important surface antigen to identify its B- and T-cell immunodominant regions. We have conducted a multi-method B-cell epitope (BCE) prediction approach using different predictor algorithms to discover the most potential BCEs. Besides, we sought among a pool of MHC class I and II-associated peptide binders provided by the IEDB server through the strict cut-off values. To design a broad-coverage vaccine, we carried out a population coverage analysis for a set of candidate T-cell epitopes and based on the HLA allele frequency in the top most-affected countries by COVID-19 (update 02 April 2020). Results: The final determined B- and T-cell epitopes were mapped on the S glycoprotein sequence, and three potential hub regions covering the largest number of overlapping epitopes were identified for the vaccine designing (I531-N711; T717-C877; and V883-E973). Here, we have designed two domain-based constructs to be produced and delivered through the recombinant protein- and gene-based approaches, including (i) an adjuvanted domain-based protein vaccine construct (DPVC), and (ii) a self-amplifying mRNA vaccine (SAMV) construct. The safety, stability, and immunogenicity of the DPVC were validated using the integrated sequential (i.e. allergenicity, autoimmunity, and physicochemical features) and structural (i.e. molecular docking between the vaccine and human Toll-like receptors (TLRs) 4 and 5) analysis. The stability of the docked complexes was evaluated using the molecular dynamics (MD) simulations. Conclusion: These rigorous in silico validations supported the potential of the DPVC and SAMV to promote both innate and specific immune responses in preclinical studies.

COVID-19 infection: comparing the knowledge, attitude and practices in a sample of nursing students

BACKGROUND

SARS-CoV-2 infection is a global health problem that is primarily detected in Italy with progressive increase in cases and deaths. To facilitate the management of the pandemic in Italy, it is essential to understand the level of attention on COVID-19. The aim of the study was to evaluate the knowledge, attitude and practices towards SARS-CoV-2 among the nursing students of University of Palermo during the rapid rise period of the COVID-19 pandemic.

METHODS

The current study was a cross-sectional study. On-line questionnaires were used for the collection of the data by providing a survey in all nursing students. The questionnaire consisted of two parts: demographics and Knowledge, Attitude and Practices (KAP) survey. A multivariate linear regression model was used and adjusted Odds Ratios (aOR) are presented.

RESULTS

525 students were interviewed and their mean age was 21.8. The overall score indicates good practices among the three courses of study (p=0.025). The Multivariable logistic regression showed that the dependent variable "Practice poor score" is statistically significant associated with these independent variables: "Other country of birth" (aOR 17.7, 95% CI 2.31-136.03), "second" (aOR 2.65, 95% CI 1.21-7.80) and "third" (aOR 2.96, 95% CI 1.31-6.72) year of study, "low perceived health status"(aOR 2.35, 95% CI 1.04-5.30) and "Knowledge poor score (aOR 3.05, 95% CI 1.06-8.77).

CONCLUSION

Our results suggest that health education programs aimed at improving COVID-19 knowledge are helpful for nursing students to hold optimistic attitudes and maintain appropriate practices.