Oesophageal and oral ulcer tuberculous associated with human T-cell lymphotropic virus type 1 (HTLV-1) and SARS-CoV-2 infection

Oesophageal involvement due to tuberculosis (TB) and coinfection with HTLV-1 is rare and can be complicated by the presence of other infections that affect the mucosa of the upper respiratory tract, such as COVID-19. We present the case of a 27-year-old male patient, with 3 months of illness, weight loss, dysphagia, and ulcers in the oral cavity. Tomography showed oesophageal perforation and after oesophageal ulcer biopsy, TB was diagnosed, in addition to infection by HTLV-1 and severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). The patient responded satisfactorily to antituberculous treatment and corticosteroids. Considering the association between rare extrapulmonary tuberculosis and other immunosuppressive pathologies, it is crucial to identify these pathologies in such patients.

19th Seminar on Tropical Pathology and Public Health 12th Biotechnology Week 1st Physical Therapy Week, Virtual, 23-25 November 2022

These proceedings comprise 85 articles spanning diverse fields such as bacteriology, molecular biology, biotechnology, dermatology, infectious and parasitic diseases, epidemiology, physiotherapy, immunology, mycology, parasitology, pathology, collective health, and virology. The articles delve into a wide range of research topics, from repurposing drugs for Mycobacterium abscessus complex infections to utilising artificial intelligence for SARS-CoV-2 diagnosis. In bacteriology, investigations explore the correlation between smoking and Helicobacter pylori infection in gastric adenocarcinoma patients, as well as the resistance profiles of Staphylococcus aureus and Pseudomonas aeruginosa in tracheostomised children. Molecular biology studies focus on gene polymorphisms related to diseases like paracoccidioidomycosis. Biotechnology research emphasises bioactive molecules in species like Croton urucurana and the development of computational models for cytotoxicity prediction. Dermatology articles address stability characterisation in vegetable oil-based nanoemulsions. The section on infectious and parasitic diseases encompasses studies on COVID-19 vaccine response in pregnant women and the impact of infection prevention measures in rehabilitation hospitals. Epidemiology investigations analyse trends in premature mortality, tuberculosis in diabetic patients, and public adherence to non-pharmacological COVID-19 measures. Physiotherapy research covers topics such as telerehabilitation through a developed game and the prevalence of congenital anomalies. Immunology studies explore immune responses in HIV and Leishmaniasis, whilst mycology investigates the biotechnological potential of fungi from the cerrado biome. Parasitology research evaluates treatment efficacy against vectors parasites such as Aedes aegypti and Toxoplasma gondii. Pathology articles discuss intentional intoxication in cattle and the influence of curcumin on acute kidney injury therapy. Collective health studies focus on intervention plan development in healthcare settings and pesticide use in horticulture. Lastly, virology research investigates parvovirus occurrence in hospitalised children during the COVID-19 pandemic, hidden hepatitis B virus infection in inmates, and the prevalence of HPV and HTLV-1/2 infections in specific populations.

Effect of Macrophages and Latent Reservoirs on the Dynamics of HTLV-I and HIV-1 Coinfection

Human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus type I (HTLV-I) are two retroviruses that have a similar fashion of transmission via sharp objects contaminated by viruses, transplant surgery, transfusion, and sexual relations. Simultaneous infections with HTLV-I and HIV-1 usually occur in areas where both viruses have become endemic. CD4+T cells are the main targets of HTLV-I, while HIV-1 can infect CD4+T cells and macrophages. It is the aim of this study to develop a model of HTLV-I and HIV-1 coinfection that describes the interactions of nine compartments: susceptible cells of both CD4+T cells and macrophages, HIV-1-infected cells that are latent/active in both CD4+T cells and macrophages, HTLV-I-infected CD4+T cells that are latent/active, and free HIV-1 particles. The well-posedness, existence of equilibria, and global stability analysis of our model are investigated. The Lyapunov function and LaSalle's invariance principle were used to study the global asymptotic stability of all equilibria. The theoretically predicted outcomes were verified by utilizing numerical simulations. The effect of including the macrophages and latent reservoirs in the HTLV-I and HIV-1 coinfection model is discussed. We show that the presence of macrophages makes a coinfection model more realistic when the case of the coexistence of HIV-1 and HTLV-I is established. Moreover, we have shown that neglecting the latent reservoirs in HTLV-I and HIV-1 coinfection modeling will lead to the design of an overflow of anti-HIV-1 drugs.

Global stability of a general HTLV-I infection model with Cytotoxic T-Lymphocyte immune response and mitotic transmission

Mathematical models have been considered as a robust tool to support biological and medical studies of human viral infections. The global stability of viral infection models remains an important and largely open research problem. Such results are necessary to evaluate treatment strategies for infections and to establish thresholds for treatment rates. Human T-lymphotropic virus class I (HTLV-I) is a retrovirus which infects the CD4+T cells and causes chronic and deadly diseases. In this article, we developed a general nonlinear system of ODEs which describes the within-host dynamics of HTLV-I under the effect Cytotoxic T-Lymphocytes (CTLs) immunity. The mitotic division of actively infected cells are modeled. We consider general nonlinear functions for the generation, proliferation and clearance rates for all types of cells. The incidence rate of infec-tion is also modeled by a general nonlinear function. These general functions are assumed to satisfy a set of suitable conditions and include several forms presented in the literature. We determine a bounded domain for the system's solutions. We prove the existence of the system's equilibrium points and determine two threshold numbers, the basic reproductive number R0 and the CTL immunity stimulation number R1. We establish the global stability of all equilibrium points by con-structing Lyapunov function and applying Lyapunov-LaSalle asymptotic stability theorem. Under certain conditions it is shown that if R0 <= 1, then the infection-free equilibrium point is globally asymptotically stable (GAS) and the HTLV-I infection is cleared. If R1 < 1 < R0, then the infected equilibrium point without CTL immunity is GAS and the HTLV-I infection becomes chronic with no sustained CTL immune response. If R1 > 1, then the infected equilibrium point with CTL immu-nity is GAS and the infection becomes chronic with persistent CTL immune response. We present numerical simulations for the system by choosing special shapes of the general functions. The effect of Crowley-Martin functional response and mitotic division of actively infected cells on the HTLV-I progression are studied. Our results cover and improve several ones presented in the literature.(c) 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).

Impact of COVID-19 Pandemic on Seroprevalence of HIV, HBV, HCV and HTLV I-II in a Blood Bank in Medellín, Colombia, 2019-2022.

The objective of this research was to analyze the impact of the COVID-19 pandemic on seroprevalence of HIV, HBV, HCV and HTLV I-II in donors from a blood bank in Medellin, Colombia, 2019-2022. A cross-sectional analytical study was carried out with three groups: pre-pandemic with 14,879 donors; preventive isolation with 9035; and selective isolation + new normality with 26,647 subjects. Comparisons were made with Chi2 and Bonferroni adjustment, Kruskal-Wallis' H with Dunnett's post-hoc, prevalence ratios, and multivariate logistic regression. COVID-19 decreased donations of men, altruistic and repetitive donors, and increased the age of donors. HIV increased with the COVID-19 pandemic, while HBV, HCV, and HTLV I-II decreased. The pandemic had an independent effect on these viral infections. These findings constitute an alert about what may be happening in the general population and show the importance of improving epidemiological surveillance and the investigation of these infections.

Development and Validation of a Rapid Screening Test for HTLV-I IgG Antibodies.

Initial diagnosis of human T cell lymphotropic virus (HTLV) infections is mainly based by detecting antibodies in plasma or serum using laboratory-based methods. The aim of this study was to develop and evaluate a rapid screening test for HTLV-I antibodies. Our rapid screening test uses HTLV-I p24 antigen conjugated to gold nanoparticles and an anti-human IgG antibody immobilized to a nitrocellulose strip to detect human HTLV-I p24-specific IgG antibodies via immunochromatography. Performance of the rapid screening test for HTLV-I was conducted on a total of 118 serum specimens collected in Salvador, Bahia, the epicenter for HTLV-1 infection in Brazil. Using a Western blot test as the comparator, 55 serum specimens were HTLV-I positive, 5 were HTLV-I and HTLV-II positive, and 58 were negative. The sensitivity of the rapid screening test for HTLV-1 was 96.7% and the specificity was 100%. The rapid screening test did not show cross-reaction with serum specimens from individuals with potentially interfering infections including those caused by HTLV-II, HIV-I, HIV-II, hepatitis A virus, hepatitis B virus, hepatitis C virus, herpes simplex virus, Epstein-Barr virus, SARS-CoV-2, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Toxoplasma gondii, and Plasmodium falciparum. The rapid screening test also did not show cross-reaction with potentially interfering substances. Strategies for HTLV diagnosis in non- and high-endemic areas can be improved with low-cost, rapid screening tests.

COVID-19 among People Living with HTLV-1 Infection in Rio de Janeiro, Brazil.

The impact of coronavirus disease 2019 (COVID-19) on people living with human T-cell leukemia virus type 1 (HTLV-1) is unknown. The aim of this study is to evaluate the COVID-19 risk factors and outcomes of HTLV-1-infected individuals. A retrospective study of seropositive HTLV-1 outpatients seen during the COVID-19 pandemic period (2020-2022) was conducted in a Tertiary Hospital in Rio de Janeiro, Brazil. We compared the demographic and comorbidity/risk factors in patients with COVID-19 and non-COVID-19 diagnoses. In addition, the clinical features of COVID-19 and vaccination status were also investigated in 51 HTLV-1-infected individuals. The majority (88.2%) had COVID-19 comorbidity/risk factors. Seven cases were vaccinated against COVID-19. Overall, 19 out of 51 (37.3%) individuals were diagnosed with COVID-19. We found differences only in the frequency of anxiety in both groups: 57.9% in the COVID-19 group vs. 15.6% in the non-COVID-19 (p < 0.05) group. Thirteen out of nineteen (68%) of the COVID-19 cases progressed to mild/moderate illness, one remained asymptomatic, and 26.3% progressed to severe illness. All of the individuals recovered at home, but the majority (57.9%) developed post-COVID-19 symptoms: anosmia and ageusia (31.6%), worsening anxiety (15.8%), and a feeling of pain in the legs (15.8%). The patients with post-COVID-19 conditions were unvaccinated. Our findings show that HTLV-1 did not increase the risk of lethal COVID-19 and underline the importance of promoting mental health in HTLV-1-infected individuals.

Stability analysis of SARS-CoV-2/HTLV-I coinfection dynamics model

Although some patients with coronavirus disease 2019 (COVID-19) develop only mild symptoms, fatal complications have been observed among those with underlying diseases. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative of COVID-19. Human T-cell lymphotropic virus type-I (HTLV-I) infection can weaken the immune system even in asymptomatic carriers. The objective of the present study is to formulate a new mathematical model to describe the co-dynamics of SARS-CoV-2 and HTLV-I in a host. We first investigate the properties of the model's solutions, and then we calculate all equilibria and study their global stability. The global asymptotic stability is examined by constructing Lyapunov functions. The analytical findings are supported via numerical simulation. Comparison between the solutions of the SARS-CoV-2 mono-infection model and SARS-CoV-2/HTLV-I coinfection model is given. Our proposed model suggest that the presence of HTLV-I suppresses the immune response, enhances the SARS-CoV-2 infection and, consequently, may increase the risk of COVID-19. Our developed coinfection model can contribute to understanding the SARS-CoV-2 and HTLV-I co-dynamics and help to select suitable treatment strategies for COVID-19 patients who are infected with HTLV-I. © 2023 the Author(s), licensee AIMS Press.

Breastfeeding With Infectious Diseases

Aims: Human breast milk remains an important source of protection against infection, inflammation, allergy and long-term metabolic disorders for the breastfed offspring. During cases of ongoing infection, the dilemma faced by both medical health professionals and mothers is the need to balance the risk of continuing versus temporarily or permanently ceasing to breastfeed. The aim of our article is to review existing literature regarding breastfeeding during acute infectious and non-infectious illnesses and to provide feasible evidence-based suggestions which can be implemented by medical practitioners during counselling of breastfeeding mothers.Method: A literature search was conducted on PubMed (US National Library of Medicine) using various combinations of keywords related to breastfeeding and the various infections. The citations from all selected articles were reviewed for additional studies.Results: Most ongoing infections are not contraindications for breastfeeding, with the exceptions of Human Immunodeficiency viruses (HIV), Human T-cell lymphotropic virus (HTLV) types 1 and 2. Even with HIV, there is increasing evidence to reassure that with adequate antiretroviral therapy, breastfeeding is likely to be safe. Of particular concern during the COVID-19 pandemic too, current evidence indicates that mothers with COVID-19 infection can safely breastfeed, and therefore initiation and continuation of breastfeeding should continue to protect the health of the babies and mothers.Conclusion: During this pandemic especially, there is a strong and urgent need to support mothers with acute infections who wish to breastfeed. With better awareness, physicians can play an important role in securing positive experiences for breastfeeding mothers and optimizing infant outcomes.

Infections and nervous system dysfunctions

Spread of pathogens to the nervous system is a serious complication of infections. In addition to infections with well-known microbes and viruses in the Western world, and the World Health Organization priorities of HIV/AIDS, malaria, and tuberculosis, several neglected tropical infectious diseases target the nervous system and have high mortality rates. Infections can cause cognitive and behavioral disturbances as well as late-onset epilepsy in survivors. The specialized environment in the brain dampens immune responses to avoid harmful effects on the nonrenewable nervous tissue. Some pathogens can therefore evade efficient elimination, persist, and be involved in interactions with nervous tissue that create balances, which, if lost by the host, can result in long-term functional disturbances. Viruses also can be useful tools to study the structure and function of the nervous system. Neuroscience can disclose mechanisms of neurodegeneration and brain dysfunctions from studies of the interplay among pathogens, nervous tissues, and immune responses that could lead to better management of brain disorders. © 2023 Elsevier Inc. All rights reserved.

Integrative and Multidisciplinary Care for People Living With Human T-Cell Lymphotropic Virus in Bahia, Brazil: 20 Years of Experience.

Brazil is home to the highest absolute number of human T-cell lymphotropic virus type-1 (HTLV-1)-infected individuals worldwide; the city of Salvador, Bahia, has the highest prevalence of HTLV-1 infection in Brazil. Due to the complex nature of several diseases associated with this retrovirus, a multidisciplinary health care approach is necessary to care for people living with HTLV-1. The Bahia School of Medicine and Public Health's Integrative Multidisciplinary HTLV Center (CHTLV) has been providing support to people living with HTLV and their families since 2002, striving to ensure physical and mental well-being by addressing biopsychosocial aspects, providing clinical care and follow-up, including to pregnant/postpartum women, as well as comprehensive laboratory diagnostics, psychological therapy, and counseling to family members. To date, CHTLV has served a total of 2,169 HTLV-infected patients. The average patient age is 49.8 (SD 15.9) years, 70.3% are female, most are considered low-income and have low levels of education. The majority (98.9%) are HTLV-1 cases, and approximately 10% have been diagnosed with tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM), while 2.2% have infective dermatitis and 1.1% have adult T-cell lymphoma. In all, 178 pregnant/postpartum women [mean age: 32.7 (±6.5) years] have received care at CHTLV. Regarding vertical transmission, 53% of breastfed infants screened for HTLV tested positive in their second year of life, nearly 18 times the rate found in non-breastfed infants. This article documents 20 years of experience in implementing an integrative and multidisciplinary care center for people living with HTLV in Bahia, Brazil. Still, significant challenges remain regarding infection control, and HTLV-infected individuals continue to struggle with the obtainment of equitable and efficient healthcare.

Diagnostic accuracy of Abbott Architect Assay as a screening tool for human T-cell leukaemia virus type-1 and type-2 infection in a London teaching hospital with a large solid organ transplant centre.

AIM: In the United Kingdom, organ donors/recipients are screened for evidence of human T-cell leukaemia virus type-1 and type-2 (HTLV-1/2) infections. Since the United Kingdom is a low prevalence country for HTLV infections, a screening assay with high sensitivity and specificity is required. Samples with repeat reactivity on antibody testing are sent to a reference lab for confirmatory serological and molecular testing. In the case of donor screen, this leads to delays in the release of organs and can result in wastage. We aim to assess whether a signal/cut-off (S/CO) ratio higher than the manufacturer's recommendation of 1.0 in the Abbott Architect antibody assay is a reliable measure of HTLV-1/2 infection. METHODS: We conducted a 5 year retrospective analysis of 7245 patients from which 11 766 samples were tested on the Abbott Architect rHTLV I/II assay. Reactive samples (S/CO >1) were referred for confirmatory serological and molecular detection (Western Blot and proviral DNA) at UK Health Security Agency, (formerly PHE, Colindale), the national reference laboratory. Electronic, protected laboratory and hospital patient databases were employed to collate data. RESULTS: A total of 45 patients had initially reactive samples. 42.2% (n = 19/45) had an S/CO ratio > 20, with HTLV infection confirmed in n = 18/19 and indeterminate confirmatory results in n = 1/19. No samples with an S/CO ratio <4 (48.9%, n = 22/45) or 4-20 (8.9%, n = 4/45) had positive confirmatory results on subsequent confirmatory testing. CONCLUSION: Samples with an S/CO >20 likely represent a true HTLV-1/2 infection. Reactive samples with an S/CO <4 were unlikely to confirm for HTLV infections. Interpretation of these ratios can assist clinicians in the assessment of low reactive samples and reiterates the need for faster access to confirmatory testing.

Spastic Paraparesis After SARS-CoV-2 Infection Without Radiological Changes.

Coronavirus disease 2019 (COVID-19) is primarily a disease of the respiratory system but severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may cause several immune-related complications including different neurological disorders, such as myelopathy with paraparesis.In this atypical case a female patient with progressive spastic paraparesis after COVID-19 infection, brisk reflexes and positive Babinski sign, reduced vibratory sensation to the thoracic level, elevated immunoglobulin levels (IgG) in cerebrospinal fluid, but negative magnetic resonance imaging (MRI) of the brain and spine, is presented.  A 57-year-old woman with spastic paraparesis and inability to walk was admitted to our neurological department. About four months before hospitalization, she started feeling numbness and tingling in the feet and lumbar spine area. Gradually, numbness and tingling ascended to the thoracic spine level Th7/8, and she developed weakness mostly in her legs. In the neurological exam she had spastic paraparesis. MRI of the brain, cervical and thoracic spine did not reveal any signal abnormality. Serological testing for SARS-CoV-2 was performed and results were highly positive IgG and IgM+IgA levels. The lumbar puncture finding confirmed the suspicion of immune-related complications after SARS-CoV-2 infection (intrathecal IgG synthesis).  This case draws attention to spastic paraparesis or progressive MRI-negative myelitis after SARS-CoV-2 infection, which obviously has immune-mediated pathogenesis that happen in response to the virus or its antibodies. Similarities in spastic paraparesis after human T-lymphotropic virus (HTLV-1) or human immunodeficiency virus (HIV-1) and SARS-CoV-2 infections were observed. The patient had a good response to corticosteroid therapy and had good recovery.

Strengths, Weaknesses, Opportunities and Threats (SWOT) Analysis of the Implementation of Public Health Policies on HTLV-1 in Brazil.

Human T lymphotropic virus 1 (HTLV-1) is a public health issue for most countries and imposes important consequences on patients' health and socioeconomic status. Brazil is one of the global leaders of the public health response to these viruses. The country has challenges to overcome to implement meaningful policies aiming to eliminate HTLV-1/2. An analysis of strengths, weaknesses, opportunities, and threats (SWOT) for the implementation of public health policies on HTLV-1/2 was performed. The strengths identified were the Brazilian Unified Health System (SUS); Brazilian expertise in public health programs successfully implemented; currently available policies targeting HTLV; and strong collaboration with researchers and patient's representative. Lack of awareness about HTLV, insufficient epidemiological data, lack of reference centers for patient care, insufficient availability of confirmatory tests, lack of universal antenatal screening, and absence of cost-effectiveness studies were identified as weaknesses. Some interesting opportunities included the increased interest from international organizations on HTLV, possibility of integrating HTLV into other programs, external funding for research, available online platforms, opportunity to acquire data from HTLV-1/2 surveillance to gather epidemiological information, and HTLV policies that were implemented independently by states and municipalities. In addition to the COVID-19 pandemic, existing demands from different diseases, the country's demography and its marked sociocultural diversity and the volatility of the technical team working with HTLV-1/2 at the Brazilian Ministry of Health are threats to the implementation of public policies on HTLV-1/2. This SWOT analysis will facilitate strategic planning to allow continuous progress of the Brazilian response to HTLV-1/2 infection.

Clinical and Laboratory Outcomes in HIV-1 and HTLV-1/2 Coinfection: A Systematic Review.

Aim: To perform a systematic review to describe the available findings on clinical outcomes in HIV-1 and HTLV-1/HTLV-2 co-infected individuals since 1995. Design: This Systematic Review used PECO criteria follow by PRISMA reporting guidelines and registered as CRD42021279062 (Prospero database). The Newcastle-Ottawa Scale assessed the methodological quality of included studies. Data Collection and Analysis: A systematical search in PubMed/MEDLINE, Embase, Web of Sciences databases for cross-sectional, case-control, or cohort studies design to identify clinical and laboratorial outcomes related to HIV-1 and HTLV-1/2 coinfection. Search strategy: [("HIV-1" AND "HTLV-1" OR "HTLV-2") AND ("Coinfection") AND (1990/01/01:2021/12/31[Date- Publication])]. Results: A total of 15 articles were included on this systematic review describing data of 2,566 mono and coinfected patients, 58% male, with mean age was 35.7 ± 5.7 years. HIV-1 and HTLV-1 coinfected patients were more likely to had shorter survival and faster progression to death or mortality than monoinfected ones. Coinfected had higher CD4 cell counts and less likelihood of ART use. In addition, higher frequency of diseases like ichthyosis (22.2 vs. 6.8%), scabies (18.6 vs. 0%), candidiasis (42 vs. 12%), Strongyloidiasis (15.4 vs. 2%) and neurological manifestations like encephalopathy, peripheral neuropathy and HAM/TSP were more frequently reported in coinfected patients. Conclusions: HIV-1 and HTLV-1 coinfection and HIV-1 and HTLV-1 /2 triple coinfection were related to shorter survival, higher mortality rate, and faster progression to death, while coinfection by HIV-1/HTLV-2 seems to have neutral association with longer survival, slower AIDS progression, and lower mortality rate. The available evidence indicates an urgent need for prevention and control measures, including screening, diagnosis, and treatment of HIV-1 and HTLV-1/2 coinfected patients. Test-and-treat strategy for patients living with HIV in areas endemic for HTLV infection is mandatory, to avoid the risks of delayed therapy and death for coinfected patients. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42021279062.

Short Communication: Impact of COVID-19 on Case Reporting for HTLV and HIV-2 in Spain.

The medical demand imposed by COVID-19 has distracted proper care of other illnesses. Herein, we report the impact on new diagnoses of HTLV-1, HTLV-2, and HIV-2 in Spain, where these infections are mostly driven by immigration flows from endemic regions. As expected, case reporting declined for all three retroviral infections with respect to prior years. Furthermore, late presentations were more common. The two major reasons for these observations were significant declines in the arrival of foreigners from endemic regions and a shift in medical resources to prioritize COVID-19.

Development of in-house ELISAs for the detection of anti-SARS­CoV­2 RBD and N IgG and IgM antibodies in biological samples.

By the end of year 2019, the new virus SARS-CoV-2 appeared, causing the Coronavirus Disease 2019 (COVID-19), and spread very fast globally. A continuing need for diagnostic tools is a must to contain its spread. Till now, the gold standard method, the reverse transcription polymerase chain reaction (RT-PCR), is the precise procedure to detect the virus. However, SARS-CoV-2 may escape RT-PCR detection for several reasons. The development of well-designed, specific and sensitive serological test like enzyme immunoassay (EIA) is needed. This EIA can stand alone or work side by side with RT-PCR. In this study, we developed several EIAs including plates that are coated with either specially designed SARS-CoV-2 nucleocapsid or surface recombinant proteins. Each protein type can separately detect anti-SARS-CoV-2 IgM or IgG antibodies. For each EIAs, the cut-off value, specificity and sensitivity were determined utilizing RT-PCR confirmed Covid-19 and pre-pandemic healthy and other viruses-infected sera. Also, the receiver operator characteristic (ROC) analysis was performed to define the specificities and sensitivities of the optimized assay. The in-house EIAs were validated by comparing against commercial EIA kits. All in-house EIAs showed high specificity (98-99%) and sensitivity (97.8-98.9%) for the detection of IgG/IgM against RBD and N proteins of SARS-CoV-2. From these results, the developed Anti-RBD and anti-N IgG and IgM antibodies EIAs can be used as a specific and sensitive tool to detect SARS-CoV-2 infection, calculate the burden of disease and case fatality rates.

The Role of Bcl-xL Protein in Viral Infections.

Bcl-xL represents a family of proteins responsible for the regulation of the intrinsic apoptosis pathway. Due to its anti-apoptotic activity, Bcl-xL co-determines the viability of various virally infected cells. Their survival may determine the effectiveness of viral replication and spread, dynamics of systemic infection, and viral pathogenesis. In this paper, we have reviewed the role of Bcl-xL in the context of host infection by eight different RNA and DNA viruses: hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), influenza A virus (IAV), Epstein-Barr virus (EBV), human T-lymphotropic virus type-1 (HTLV-1), Maraba virus (MRBV), Schmallenberg virus (SBV) and coronavirus (CoV). We have described an influence of viral infection on the intracellular level of Bcl-xL and discussed the impact of Bcl-xL-dependent cell survival control on infection-accompanying pathogenic events such as tissue damage or oncogenesis. We have also presented anti-viral treatment strategies based on the pharmacological regulation of Bcl-xL expression or activity.

The Complex Relationship between HTLV-1 and Nonsense-Mediated mRNA Decay (NMD).

Before the establishment of an adaptive immune response, retroviruses can be targeted by several cellular host factors at different stages of the viral replication cycle. This intrinsic immunity relies on a large diversity of antiviral processes. In the case of HTLV-1 infection, these active innate host defense mechanisms are debated. Among these mechanisms, we focused on an RNA decay pathway called nonsense-mediated mRNA decay (NMD), which can target multiple viral RNAs, including HTLV-1 unspliced RNA, as has been recently demonstrated. NMD is a co-translational process that depends on the RNA helicase UPF1 and regulates the expression of multiple types of host mRNAs. RNA sensitivity to NMD depends on mRNA organization and the ribonucleoprotein (mRNP) composition. HTLV-1 has evolved several means to evade the NMD threat, leading to NMD inhibition. In the early steps of infection, NMD inhibition favours the production of HTLV-1 infectious particles, which may contribute to the survival of the fittest clones despite genome instability; however, its direct long-term impact remains to be investigated.