Day 1 :
- General Virology | STD & HIV/ AIDS and Emerging Viral Diseases | Molecular and Cellular Virology | Hepatic viral diseases
Location: Barcelona, Spain
Session Introduction
Prashant Bhat
Department of Health and Family Welfare, India
Title: Hepatitis-A in a residential school campus: An outbreak investigation, Karnataka, India 2019-20
Biography:
Prashant Bhat is affiliated from Distrct Vector Borne Disease Control Officer, Udupi and India EIS Officer (South) at ICMR NIE Chennai, India
Abstract:
Background: Hepatitis outbreaks are common in Indian schools. Between 2011 and 2013, India reported 44,663 Hepatitis-A cases, from 291 outbreaks, of which 73% were school-going children. A residential school in Karnataka reported 157 cases of jaundice on December 28, 2019. We investigated this outbreak to identify the source and propose recommendations.
Methods: In line with the Centre for Disease Control's outbreak investigation guidelines, after confirming the Hepatitis-A outbreak, we defined the case-patients as an inmate of the school campus with jaundice or dark urine and one associated symptom (Fever, Vomiting, Abdominal Pain, Itching, Malaise, Anorexia) from 01 August 2019 to 06 January 2020. We actively searched cases and conducted the descriptive analysis. We formulated a hypothesis and tested it with a case-control study. We inspected pipelines of water supplies. We also interacted with food handlers and the cafeteria.
Results: We identified 484 (11%) case-patients among 4335 students and staff. The first case was reported on 17 August. While the pattern was sporadic (n=56) initially, it started increasing in December and peaked on 20th December (n=26). Cases declined till 21 January 2020. Attack rates were higher among the 10-13 years age-group (15%), followed by the 14-16 (13%). Females had higher attack rates (15.3%). The median duration of illness was 17 (1-97) days, and hospitalisation was 11 (1-94) days. Nine hostels supplied by a single water source (Sump-A) had higher attack rates (5.5, 21.5%). The analytical study showed that consuming Sump-A water was associated with the outbreak (OR: 6.74, 95% CI: 2.90-15.62). The Sump-A had multiple open holes on inspection, the supply line had leakage points, and the water was not chlorinated. The garden surrounding sump-A was sprayed with untreated sewage.
Conclusion: Unprotected water of Sump-A led to the outbreak. Securing the Sump-A, chlorination of water and repairing the supply line were suggested as remedial measures.
Pooja Khurana
Manav Rachna International Institute of Research and Studies, India
Title: Estimation of the reproductive number for the recurrence of COVID-19 Infections
Biography:
Dr. Pooja Khurana is a professional academician with strong analytical skills seeking the position of Associate professor and researcher focusing in Biomathematical modeling (epidemiological modeling). She has published multiple papers in the areas of biomathematics, social networking indexed in Scopus, Web of Science; presented various mathematical reports in conferences and seminars. She is an expert in applying mathematical principles to complex real-world problems and well-versed with mathematical software such as Mathematica, MATLAB. She is currently mentoring three scholar candidates and is skilled with applying the concepts of statistics, numerical analysis, and probability in building and simulation of mathematical models for improving healthcare.
Abstract:
Alzheimer is a step wise and progressive neurodegenerative disorder caused by neuronal cell death. The predictable changes within the brain due to AD usually turn out almost two decades prior to the emergence of symptoms. This slightest phase of symptoms offers a great chance for therapeutic potential which can be directed to predict the progression of clinical AD. Mild cognitive impairment is the stage before AD. The transformation from MCI to AD has been of agreeable interest for the analysis of biomarkers that are beneficial for early AD detection. Determination of causative agents is a necessary step for the understanding and to figure out the effective treatment of a disease. Viruses are such agents that are responsible for the characteristic features of AD in the patients. The assessment of significant biomarkers can be overriding for the prompt pre-clinical diagnosis, therapeutics, examining and treatment, monitoring, and continuing phases of AD analysis, for that graph theoretical measures can be utilized to infer neurobiological mechanisms leading to loss of cognitive functions, behavioural and other brain disorders. Also, complex networks of brain can be well characterized by graph functions that distinguish Alzheimer brain from the normal ones. This paper highlights the studies for the viruses that along with the other genetic factors lead to AD and role of graph theory as an emerging tool for the early diagnosis of AD.
Wipawee Nittayananta
Thammasat University, Thailand
Title: Microbicide gel containing ellagic acid can inhibit HIV-1 infection
Biography:
Wipawee Nittayananta is affiliated from Faculty of Dentistry Thammasat University, Thailand
Abstract:
Objective: The purpose of this study was to investigate the in vitro effects of ellagic acid both in solution and gel forms on HIV-1 replication, viral enzyme activity and cytokine secretion by infected cells.
Methods: The anti-HIV-1 activity of ellagic acid in solution was determined in vitro using infection of TZM-bl cells by the R5-tropic pBaLEnv-recombinant viruses. Viral growth was assessed by β-galactosidase production and Nano-GloLuciferase assay. The antiviral effect of ellagic acid in gel formulation (Ellagel), as would be used for vaginal application, was also investigated by neutralization assay. The effect of ellagic acid on cytokine secretion of TZM-bl cells was determined by multiplexed bead array after 48 h of HIV-1 exposure.
Results: Ellagic acid in solution, added either 1 h before or immediately after HIV-1 exposure, suppressed replication of R5-tropic virus in TZM-bl cells up to 69%. Ellagic acid up to 100 µM was not toxic to either TZM-bl or primary vaginal cells. Ellagel at the concentrations of 50 µM and 25 µM inhibited the virus by 84% and 56%, respectively. In assays of specific HIV-1 enzyme activity, Ellagel inhibited HIV-1 integrase (IC5047.32 µM) but not protease. Ellagic acid did not significantly modulate cytokine secretion.
Conclusion: We conclude that ellagic acid either in solution or in gel form inhibits HIV infection without adverse effects on target cells. Thus, vaginal formulations containing ellagic acid could be tested as a new microbicide against HIV-1 infection.
Zsolt Csabai
University of Szeged, Hungary
Title: The analysis of antiviral effect of photoreactive surfaces
Biography:
Zsolt Csabai, PhD, Biologist Senior lecturer in Department of Medical Biology, University of Szeged. He was born in Senta, Serbia. He began his studies at the University of Szeged, Hungary. Bachelor of Biology 2011, Master of Biology (molecular-, immune-, and microbiology) 2013. He had finished his PhD studies in 2018 and gained experience in transcriptome analysis of viruses (“Multiplatform analysis of herpesvirus transcriptomes”). During the past 12 years he worked on the description of several virus transcriptomes (HSV1, hCMV, EBV, PRV, ASFV, VZV, VACV, AcMNPV, PERV, PCV1). He also had a wide range of experience in sequencing technologies like Oxford Nanopore Technologies (ONT), Pacific Biosciences Technologies (PacBio) MiSeq Illumina platform.
Abstract:
The pandemic situations pointed out the vulnerability of population to infectious diseases. Reactive plasmonic titanium dioxide-based polymeric nanocomposite film was prepared with a thickness of 1-1.5 µm, which produces Reactive Oxygen Species (ROS) under visible light irradiation (λ≥435 nm) [1]. These species are suitable for photooxidation of adsorbed organic molecules (e.g., benzoic acid) on the nanocomposite surface. Moreover, high molecular weight proteins are also degraded or partially oxidized in this process on the composite surface. Since the Ag0-TiO2/polymer composite film used showed excellent reactivity in the formation of OH• radicals, the photocatalytic effect on high molecular weight (M=∼66.000 Da) Bovine Serum Albumin (BSA) protein was investigated [2]. This film showed obvious antibacterial properties against Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Acinetobacter baumannii, or Methicillin-Resistant Staphylococcus Aureus (MRSA) [3,4]. The focus of our studies is to analyze photoreactive composite film surfaces that may have antiviral effects upon illumination. Viruses are unable to propagate on lifeless surfaces, they can retain their infectivity and spread further on contact with these surfaces. We tested this antiviral effect using an afirborne-transmitted Pseudorabies virus. As a result, we obtained a drastic decrease in infection capability of the virus on the photoreactive surface compared to the control surface.
Conclusion: The synthetized plasmonic Ag-TiO2 photocatalyst containing composite layers are able to produce enough surface ROS to eliminate viable viruses. We demonstrated the antiviral effect illuminated photoreactive surfaces exerts antiviral effect in liquid and dried states too.
Istvan Prazsak
University of Szeged, Hungary
Title: Multiplatform, integrative approach to assess varicella zoster virus transcriptome
Biography:
Istvan Prazsak, PhD, is an assistant professor at the University of Szeged, Hungary, Department of Medical Biology. He earned MsC in biology and environmental sciences in 2005. He worked as a pre-doctorate researcher at the Department of Genetics, University of Szeged, Hungary, where his research interest covered phylogenetics of arthropod taxa, including Chelicerata. He described a new species of ladybird spiders. From 2010 he joined to the 3G Genomics research group at the Department of Medical Biology, Faculty of Medicine, University of Szeged and focused on the recombinant gene technology and later on transcriptomics of Herpesviruses. From 2018 he has been a PhD student at the Doctoral School of Interdisciplinary Medicine, University of Szeged and Faculty of Medicine under the supervision of Prof Zsolt Boldogkoi and Dr Dora Tombacz. He earned PhD in 2021, entitled: “The Long Read Sequencing of the Varicella-Zoster Virus and Vaccinia Virus Transcriptome”.
Abstract:
In order to understand how viruses are capable of conducting their life cycles and manipulating host immune system it is important to know their gene expression pattern. Existing high-throughput, Short-Read Transcriptome Sequencing Methods (SRS), such as Illumina sequencing have limitations in capturing all possible mRNA isoforms produced by a virus. We circumvent those difficulties by using Long-Read Sequencing (LRS) and found many new, hitherto unknown viral mRNAs in a variety of length among the members of Herpesviruses [1–4]. The Herpesvirus genomes, like other viral genomes consist of complex, gene-dense structures, which can be explained by the parsimonious evolution of viruses, which also enables their high coding capacity. For SRS is difficult, unless it is unable to distinguish these complex transcriptomic structures, however LRS can detect length isoforms of mRNAs very well, especially in overlapping transcriptomic regions [5]. Albeit, many newly found transcript isoforms of Herpesviruses remained unevaluated, due to the low level of abundance, or uncertain detection of transcriptional start and end positions [6,7]. Therefore, the reanalysis of transcriptomic data is in demand. A new integrative elaboration of SRS and LRS transcriptomic analysis of transcriptomic data can resolve the hiatus of Herpesvirus transcriptome annotation. With this new approach, we were able to reconstitute - to our knowledge - the most precisely annotated lytic transcriptome of Varicella Zoster Virus.
Results: We have collected transcriptomic data from the NCBI GenBank, which represented all of the uploaded VZV SRS and LRS raw files up to date. Altogether more than 2.5 Billions of reads were used from the results of seven different research groups. We have used Illumina HiSeq, as well as Next Seq CAGE data files and compared them to the downloaded data files of Oxford Nanopore Technologies (ONT) MinION cDNA as well as dRNA sequencing libraries, including Cap-selected, polyA-selected cDNA and dRNA. To enhance the statistical variability of samples for the detection of transcription start (TSS) and end positions (TES) as well as intron positions we re-sequenced the lytic VZV transcriptome. Viruses were propagated in MRC-5 cells and whole transcriptome was sequenced using a random, a targeted and a Terminator treated library preparation protocol on ONT MinION platform.
In our bioinformatics pipeline raw reads were treated according their sequencing platform. SRS reads have been trimmed and quality checked by using Trimgalore and FastQC prior to mapping by STAR aligner to the reference genome of VZV (NC_001348.1), thereafter intron-donor/acceptor positions were determined. Furthermore, mapped Illumina reads were re-analyzed by using CAGEfightR to determine TSS positions. Raw LRS data have been re-basecalled by Guppy and mapped by minimap2 to the reference genome of VZV. The LoRTIA tool - developed by our team [8]- was used to access TSS, TES and intron positions from LRS data.
Conclusion: By using our integrative analysis, the majority of previously described TSS, TES and intron positions were confirmed and several new, hitherto unknown, intron isoforms and 5’ UTR or 3’ UTR length isoforms of viral transcripts were detected. Our data support the hypothesis, that viral transcription can be analyzed with base-precision by using high coverage SRS, however there is a 2-5 nt uncertainty within 10 nt window within the same sample using different software for TSS determination. We were able to determine at least forty new TSSs, twenty new TESs and thirty new introns in the VZV transcriptome.
Importance of research: We have used a multiplatform and integrative approach of independent transcriptomic data to obtain a detailed transcriptional landscape of transcriptional positions of lytic VZV transcriptome combining both ONT MinION and Illumina sequencing techniques. Solely short read sequencing is impaired to reconstruct overlapping transcript isoforms unlike long read sequencing techniques; however LRS can fail to detect intron isoforms in low abundance. Combining methods, we utilized the advantages of the two different sequencing platforms and revealed a complex mesh of viral RNAs in VZV transcriptome.
Barbara Fialho Carvalho Sampaio
University of Sao Paulo, Brazil
Title: Saliva as a source of antibodies for MMR vaccine screening in teenagers
Biography:
Barbara Fialho C Sampaio, is coordinator of clinical research and Posdoctoral Researcher in the Medical School of Sao Paulo University. Develop innovative diagnostic research using non-invasive techniques, which aims to create possibilities for expanding diagnosis of infectious diseases. She is focused today is on the detection of measles, rubella and mumps in human saliva, such as had developed a new diagnostic technique to detect the vaccination status of children using saliva as an alternative biological fluid to blood.
Abstract:
The use of safe and effective vaccines is a well-established public health intervention, with a major impact on the fall in the prevalence of infectious diseases. In the absence of environmental transmission, vaccines do not work for life, as originally detected. This has now generated the occurrence of vaccinated susceptible people, which allows the importation of diseases, since vaccination coverage does not equate to population immunity. The serological control of the vaccination status and the protection of a population is essential, and its execution is not friendly due to the blood collection necessary for the tests. In these assays, the specific IgG for the vaccine agent is quantified, it would be important to detect IgA as well. This is an immunoglobulin secreted for mucous membranes that neutralizes or directs the agent to non- permissive neutrophils, it is very important in vaccine protection, but difficult to detect and quantify. Saliva can be a friendly alternative material as a source of IgA and IgG for use in conventional tests and its obtainment is not invasive, facilitating the acceptance of these studies in protected groups. We standardized assays with detection of antibodies in solid phase, to prospect for effective vaccine coverage in adolescents using saliva as a biological fluid. Once established and standardized, these techniques will allow for eventual vaccine control without the need for aversive blood collection, adequate public health measures, such as revaccination, can be adequately planned.
According to the State of the World’s Vaccines and Immunization report, “Vaccination-even with the addition of new, more expensive vaccines-remains one of the most cost-effective health interventions”. The publication notes that more children are reached with the immunization of one hundred million children per year in the period 2005-2007, approximately. And the benefits of immunization are increasingly extended to adolescents and adults, providing protection against potentially fatal diseases, such as influenza, meningitis and cancers that occur in adulthood.
Some authors have demonstrated that there may be a lack of response to the vaccine, called Primary Vaccine Failure (FVP), in about 2% to 5% for measles, 3% to 7% for mumps and 2% to 5% for rubella. Among the main causes of PVF are the presence of maternal antibodies and the improper conditions of the vaccine (handling, administration, cold chain). It has also been shown that Secondary Vaccine Failure (FVS) can occur, which is the drop in antibody levels, which over time can reach levels so low or undetectable that they do not provide more protection. These studies have observed that the levels of antibodies after vaccination are lower than after natural infection.
For these reasons, even with an effective immunization program in a child population, birth and the vaccination period can generate susceptible after a few years; therefore, vaccination coverage may not be equivalent to population immunity. During the past few decades, the triple viral vaccine has been introduced into immunization policy in several countries. In order to have a good immunization, two doses are recommended, the first at 12-15 months of age and the second at 4-6 years of age, in order to cover possible vaccine failures.
The vaccination process is the most effective public health intervention in the control of infectious diseases. The detection of the presence of specific IgG antibodies in serum has numerous medical uses, whether in detecting contact with infectious agents, such as in human toxoplasmosis or in demonstrating vaccine efficiency for some diseases such as measles