Fever Virus Research Articles

Exaggerated levels of some specific TLRs, cytokines and chemokines in Japanese encephalitis infected BV2 and neuro 2A cell lines associated with worst outcome

Japanese encephalitis (JE) disease, a viral brain fever is caused by Japanese encephalitis virus (JEV). Despite the availability of effective vaccines against this deadly infection, JE is the leading cause of epidemic viral encephalitis in children in South-east Asia. There is no treatment available for the JE disease which might be due to incomplete understanding of the pathogenesis of JE virus. The JEV infections lead to permanent neurological deficits even in those who survive from the infection. Activated microglia may play a potentially detrimental role by eliciting the expression of pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) influencing the surrounding brain tissue. Microglial activation, proinflammatory cytokine release and leukocytes trafficking are associated following JEV infection in central nervous system (CNS). How the pattern recognition receptors sense the viral nucleic acid and how the microglial and neuronal cells behaves following JEV infection is still unelucidated. There is scarcity of data on the expression levels of toll like receptors (TLRs), cytokines and chemokines in JEV infection in invitro model. To explore the molecular mechanisms of JEV infection of microglial cells and neuronal cells, we studied the expression profile of TLRs, cytokines and chemokines in JEV infected microglial cell line BV2 and Neuronal cell line Neuro 2A. For the present study, we developed the mouse model of encephalitis by intracerebral (IC) injection of JE virus for virus propagation, disease progression and damage study. Our results demonstrate the exaggerated release of some specific TLRs, cytokines and chemokines in invitro cell culture of microglial and Neuro 2A cell line, which are associated with bad outcome in invivo study.

A Review on Zoonotic Pathogens Associated with Non-Human Primates: Understanding the Potential Threats to Humans

Non-human primates (NHP) share a close relationship with humans due to a genetic homology of 75-98.5%. NHP and humans have highly similar tissue structures, immunity, physiology, and metabolism and thus often can act as hosts to the same pathogens. Agriculture, meat consumption habits, tourism development, religious beliefs, and biological research have led to more extensive and frequent contact between NHPs and humans. Deadly viruses, such as rabies virus, herpes B virus, Marburg virus, Ebola virus, human immunodeficiency virus, and monkeypox virus can be transferred from NHP to humans. Similarly, herpes simplex virus, influenza virus, and yellow fever virus can be transmitted to NHP from humans. Infectious pathogens, including viruses, bacteria, and parasites, can affect the health of both primates and humans. A vast number of NHP-carrying pathogens exhibit a risk of transmission to humans. Therefore, zoonotic infectious diseases should be evaluated in future research. This article reviews the research evidence, diagnostic methods, prevention, and treatment measures that may be useful in limiting the spread of several common viral pathogens via NHP and providing ideas for preventing zoonotic diseases with epidemic potential.

Review on Plants Used in Siddha Formulation Vatha Siletpana Sura Kudineer for the Management of Viral Fever

Siddhars said about various diseases and the treatment methods with herbs, minerals and animal products. In Siddha literatures viral fevers can be compared to Vatha Kapha Suram and therefore decoction for this Suram is taken from classical Siddha text book and the ingredients are searched for pharmacological activity and toxicity study from 118 published journal papers from Pubmed, Scopus, Google Scholar, Research Gate and Science Direct. Collected data is entered in MS excel and analysed using RFC score. All together there are 51 pharmacological activities are published for these nine ingredients. In which Anti-inflammatory has RFC=1, other properties like antipyretic, anti-tussive, bronchodialator, anti-asthmatic, analgesic, neuro-regenerative, neuroprotective, anti-diarrhoeal, anti-emetic, neuroprotective, analgesic, sedative has more than 0.55 RFC score. More than this cardioprotective, renoprotective, hepatoprotective, and other protective properties are present in more than 50% of ingredients. In toxicity studies no toxic effects are seen in in vivo studies for the ingredients The Suvai, Thanmai, Pirivu, in Siddha aspect, of these ingredients can highly reduces Vatha and Kapha disorders. Therefore, the decoction shows significant pharmacological activity for the sign and symptoms of viral infections.

The Personalized Role of Gelsemium Sempervirens: A Homoeopathic Medicine in the Treatment of Viral Fevers

Utmost individuals partake the body temperature of 98.6°F (37°C), when it aggregates the mystified grade its explicitly intended as Fever. Fever often a sign which embodiment and rebellious for approximate sort of bacterial or viral infection. A viral fever perhaps and triggers the underlying viral illness, wide-ranging zones of characterize proposition with instance of high fever, throat pain, chilliness, burning in eyes, headaches, body pain, nausea and vomiting. The confirmed cases of fever are systematically assessed and reigned for the virtuous incentive. The fever implies as seldom illness, amidst by principal cause of any viral infections, it crops up and fragmented by protuberance in intestines, lungs, air passages etc. Consequently, the immune system of body belligerent in contrast to intruding viruses and disengage the metaphors. The process of case study consists of data collection, appraisal of distribution of patients and recurrence of symptoms and their extent interiority. The Homoeopathic system proclaim the efficacy of Gelsemium Sempervirens medicine in treating fever, through the emphasis it been notoriously allied by means of enhancing the signs as an effective universal prognostic factor. This study defines as beneficial to diminish the infections and more over it strengthens the immune system in safe and effective tool, easily integrated and enhances the body's ability to restore balance in curative mode.

Study on the Changes in Common Laboratory Parameters in Dengue Patients with Secondary Bacterial Infection

Secondary bacterial infection can adversely affect the clinical course of primary viral infection indengue fever. Time consuming microbiological culture confirmations and false negative culture resultsdelay the timely initiation of antibiotics. The objective of this study was to describe the variation in thecommon laboratory parameters during the illness, identify criteria that may predict secondary bacterialinfection before microbial culture confirmation, identify the common organisms causing secondarybacterial infections and their antibiotic sensitivity patterns. A retrospective case-control study was carriedout at the Dengue Management Unit of the National Institute of Infectious Diseases, Sri Lanka. Patientstreated with antibiotics upon suspicion or culture confirmation of secondary bacterial infections andpatients not treated with antibiotics were selected for the study. Total WBC count, absolute neutrophilcount, platelet count, HCT (Hematocrit), CRP (C Reactive Protein) and average body temperature wererecorded. Independent sample t-test was used to analyze the data. Study results showed that most positivemicrobial cultures were detected on the 6th and 7th days of illness. Staphylococcus, Streptococcus, andnon-speciated Gram-positive cocci were the commonly isolated organisms. Patients with confirmedsecondary bacterial infection had significantly higher neutrophil count (3.32±0.35x103/μL, p<0.05) andlower platelet counts (49.33±7.66x103/μL, p<0.05) on the 6th and 5th day of illness respectively. Theaverage body temperature was significantly higher in the study group than the control from the fever day3 onwards (p<0.05). The study subjects were more likely to have significantly lower HCT values(38.62±1.12%, p<0.05) than their controls on the third and fourth days of fever. Overall, the present studysuggests that bacterial co-infection increases the mortality rate in dengue patients. The variation inabsolute neutrophil count, platelet count, and body temperature pattern compared to the illness day can beused along for early prediction of secondary bacterial infection.
 Keywords: dengue, bacterial infection, antibiotics, platelet count, HCT

Socialization of the prevention and Eradirection of Dengeu Fever (DHF) and Covid-19 in Pematang Kuala Vilage, Sub District Teluk Mengkudu, Serdang Bedagai Regency in 2021

Socialization is an activity to provide information from individuals to individuals and individuals to groups where this socialization has goals and benefit to the recipient of the information. The purpose of the work program for Kuliah Kerja Nyata (KKN)) this is to provide knowledge and understanding to the community in Pematang Village Kuala about the diseases caused by this virus, namely Covid-19 and Dengue Fever Dengue (DHF). The method used in carrying out this activity is lectures and lectures question and answer and share information. This socialization is carried out in order to add insight the community and provide understanding to the Pematang Kuala Village. The result of this service is that the Pematang Kuala Village community knows the differences and symptoms of the Covid-19 disease with Dengue Fever (DHF) and becomes brave to seek treatment at health services.

5-(Perylen-3-ylethynyl)uracil as an antiviral scaffold: Potent suppression of enveloped virus reproduction by 3-methyl derivatives in vitro

Amphipathic nucleoside and non-nucleoside derivatives of pentacyclic aromatic hydrocarbon perylene are known as potent non-cytotoxic broad-spectrum antivirals. Here we report 3-methyl-5-(perylen-3-ylethynyl)-uracil-1-acetic acid and its amides, a new series of compounds based on a 5-(perylen-3-ylethynyl)-uracil scaffold. The compounds demonstrate pronounced in vitro activity against arthropod-borne viruses, namely tick-borne encephalitis virus (TBEV) and yellow fever virus (YFV), in plaque reduction assays with EC50 values below 1.9 and 1.3 nM, respectively, and Chikungunya virus (CHIKV) in cytopathic effect inhibition test with EC50 values below 3.2 μM. The compounds are active against respiratory viruses as well: severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) in cytopathic effect inhibition test and influenza A virus (IAV) in virus titer reduction experiments are inhibited – EC50 values below 51 nM and 2.2 μM, respectively. The activity stems from the presence of a hydrophobic perylene core, and all of the synthesized compounds exhibit comparable 1O2 generation rates. Nonetheless, activity can vary by orders of magnitude depending on the hydrophilic part of the molecule, suggesting a complex mode of action. A time-of-addition experiment and fluorescent imaging indicate that the compounds inhibit viral fusion in a dose-dependent manner. The localization of the compound in the lipid bilayers and visible damage to the viral envelope suggest the membrane as the primary target. Dramatic reduction of antiviral activity with limited irradiation or under treatment with antioxidants further cements the idea of photoinduced ROS-mediated viral envelope damage being the mode of antiviral action.

Five-Year Trend of Adolescent Hospitalizations and Deaths in Thailand: A Secondary National Data Health Situation Analysis.

Adolescence is a critical phase for achieving human potential, serving as the foundation for later health. In 2010, the major causes of hospital admissions and deaths in Thai adolescents were related to preventable causes, specifically engagement in high-risk behaviors such as unprotected sexual intercourse, substance use and unsafe driving. We retrieved data from 1,761,667 adolescent (10-17years) hospital admissions and 6362 deaths between 2015 and 2019 from the National Health Security Office database. Trends of hospital admissions and deaths, length of stay and medical expenses by sex, age: early (10-13years) and middle adolescents (14-17years), and geographical regions were analyzed by ICD-10 disease group and single diagnosis. Hospital admissions increased in relation to the same age population from 2015 to 2019. Trends of the top 3 diagnoses shifted between disease groups from 2015 to 2019. Pregnancy retreated from the first (17.8%) to the third rank (12.2%), and arthropod-borne viral fevers advanced from the third (13.1%) to the first rank (17.1%). Injury and poisoning remained at the second rank (14.5-14.4%). Females were admitted more than males, but males had significantly longer hospital stays. Early adolescents were admitted less than middle adolescents and their hospital stay was significantly shorter. Trends of the top 3 diagnoses for deaths by disease groups remained stable: injury and poisoning (41.2%), neoplasms (10.2%), and respiratory infections (9.5%). The average direct health care cost utilized on adolescent health care was 3813 million Baht (115.54 million US Dollars) per year. Considering the top 3 disease groups, injury and poisoning had the highest average cost per hospital admission and net cost per year consuming 26.4% of the total cost. Our study highlights the cause of hospital admissions and deaths in Thai adolescents, which are mainly preventable. Adolescent health care will improve with more investment in prevention through policy, service, and education reform.

Repellent active ingredients encapsulated in polymeric nanoparticles: potential alternative formulations to control arboviruses

Dengue, yellow fever, Chinkungunya, Zika virus, and West Nile fever have infected millions and killed a considerable number of humans since their emergence. These arboviruses are transmitted by mosquito bites and topical chemical repellents are the most commonly used method to protect against vector arthropod species. This study aimed to develop a new generation of repellent formulations to promote improved arboviruses transmission control. A repellent system based on polycaprolactone (PCL)-polymeric nanoparticles was developed for the dual encapsulation of IR3535 and geraniol and further incorporation into a thermosensitive hydrogel. The physicochemical and morphological parameters of the prepared formulations were evaluated by dynamic light scattering (DLS), nano tracking analysis (NTA), atomic force microscopy (AFM). In vitro release mechanisms and permeation performance were evaluated before and after nanoparticles incorporation into the hydrogels. FTIR analysis was performed to evaluate the effect of formulation epidermal contact. Potential cytotoxicity was evaluated using the MTT reduction test and disc diffusion methods. The nanoparticle formulations were stable over 120days with encapsulation efficiency (EE) of 60% and 99% for IR3535 and geraniol, respectively. AFM analysis revealed a spherical nanoparticle morphology. After 24h, 7 ± 0.1% and 83 ± 2% of the GRL and IR3535, respectively, were released while the same formulation incorporated in poloxamer 407 hydrogel released 11 ± 0.9% and 29 ± 3% of the loaded GRL and IR3535, respectively. GRL permeation from PCL nanoparticles and PCL nanoparticles in the hydrogel showed similar profiles, while IR3535 permeation was modulated by formulation compositions. Differences in IR3535 permeated amounts were higher for PCL nanoparticles in the hydrogels (36.9 ± 1.1mg/cm2) compared to the IR3535-PCL nanoparticles (29.2 ± 1.5mg/cm2). However, both active permeation concentrations were low at 24h, indicating that the formulations (PCL nanoparticles and PCL in hydrogel) controlled the bioactive percutaneous absorption. Minor changes in the stratum corneum (SC) caused by interaction with the formulations may not represent a consumer safety risk. The cytotoxicity results presented herein indicate the carrier systems based on poly-epsilon caprolactone (PCL) exhibited a reduced toxic effect when compared to emulsions, opening perspectives for these systems to be used as a tool to prolong protection times with lower active repellent concentrations.

Use of Aquatic Insects For Biological Control of Mosquitoes (Diptera; Culicidae), Vectors of Different Diseases

Mosquitoes are important insects not only as nuisance biters but also as vectors of important diseases such as malaria, dengue, West Nile virus, chikungunya, yellow fever, filariasis, tularemia, dirofilariasis, Japanese encephalitis, Saint Louis encephalitis, Western equine encephalitis, Eastern equine encephalitis, Venezuelan equine encephalitis, Ross River fever, Barmah Forest fever, La Crosse encephalitis, and Zika fever, as well as newly detected Keystone virus and Rift Valley fever [1].

Detection of West Nile virus isolates in poultry in central Vietnam in 2015-2019

Cases of detection of RNA or ELISA markers of West Nile virus (WNV) have been recorded in many countries of Southeast Asia. At the same time, there were no reports of outbreaks of fevers caused by WNV. Perhaps this is due to the asymptomatic or very mild course of the disease or to the focus of the health systems of these countries on other viral fevers. In this work, for the first time in Vietnam, West Nile virus (WNV) RNA was detected in poultry. WNV RNA was found in three lung samples of chickens from Nghe An province collected in 2017. The isolates belonged to lineages 1a and 2, responsible for many WNV outbreaks in Europe and North America and therefore require close attention.

Mathematical modeling on co-infection: transmission dynamics of Zika virus and Dengue fever

Mathematical modeling on co-infection: transmission dynamics of Zika virus and Dengue fever

Method development and validation for quantification of six bioactive compounds (andrographolide, columbin, piperine, gallic, paracoumaric and oleanolic acids) by HPTLC.

During the spread of pandemic diseases, immunity boosting herbal drugs are taken as a preventive medicine. Kapacurak Kuṭinīr Cūraṇam is a Siddha drug used for flu like viral infections, cold and fever. Developing an analytical method to estimate the content of active phytoconstituents in such antiviral immune boosting drug will be useful in the phyto pharmaceutical industry. A precise, reliable and sensitive ordinary phase high performance thin layer chromatography (HPTLC) method has been developed and validated for identification and simultaneous estimation of six bioactive components namely like andrographolide, columbin, gallic acid, ρ-coumaric acid, piperine and oleanolic acid from any Indian traditional medicine, medicinal plant, drugs and food materials etc. The separation was achieved on silica gel 60F254 TLC plates using toluene: ethyl acetate: formic acid (7:3:0.5, v/v) as mobile phase. The gallic acid, ρ-coumaric acid, piperine markers were estimated using the densitometric scanning in absorption mode at 254nm. The densitometric scanning was done after derivatization (vanillin-sulphuric acid reagent) at λ=520nm for andrographolide, columbin and oleanolic acid. The linear regression analysis data for the calibration plots showed a correlation coefficient in the concentration range 1-5μg per band for the bioactive markers with respect to area. The method was validated for accuracy, precision, limit of detection (LOD), and quantitation of limit (LOQ). Developed method was accurate, precise and fast to ensure the quality of Kapacurak Kuṭinīr Cūraṇam.

Comparison of Dose-Response Relationships for Two Isolates of SARS-CoV-2 in a Nonhuman Primate Model of Inhalational COVID-19.

Background: As the COVID-19 pandemic has progressed, numerous variants of SARS-CoV-2 have arisen, with several displaying increased transmissibility. Methods: The present study compared dose-response relationships and disease presentation in nonhuman primates infected with aerosols containing an isolate of the Gamma variant of SARS-CoV-2 to the results of our previous study with the earlier WA-1 isolate of SARS-CoV-2. Results: Disease in Gamma-infected animals was mild, characterized by dose-dependent fever and oronasal shedding of virus. Differences were observed in shedding in the upper respiratory tract between Gamma- and WA-1-infected animals that have the potential to influence disease transmission. Specifically, the estimated median doses for shedding of viral RNA or infectious virus in nasal swabs were approximately 10-fold lower for the Gamma variant than the WA-1 isolate. Given that the median doses for fever were similar, this suggests that there is a greater difference between the median doses for viral shedding and fever for Gamma than for WA-1 and potentially an increased range of doses for Gamma over which asymptomatic shedding and disease transmission are possible. Conclusions: These results complement those of previous studies, which suggested that differences in exposure dose may help to explain the range of clinical disease presentations observed in individuals with COVID-19, highlighting the importance of public health measures designed to limit exposure dose, such as masking and social distancing. The dose-response data provided by this study are important to inform disease transmission and hazard modeling, as well as to inform dose selection in future studies examining the efficacy of therapeutics and vaccines in animal models of inhalational COVID-19.

Zika Virus NS2B-NS3 Protease: Quantum Chemical Properties Insights into Designing Inhibitory Peptides.

Zika fever affects poor and vulnerable populations, presenting cycles observed in, at least 86 countries, with no vaccine prevention or treatment available. It is known that the genus Flavivirus causes Zika Virus (ZIKV), as Dengue and Yellow Fever, whose genetic material decodes, among other proteins, a series of non-structural (NS) proteins essential for viral replication, such as NS2B-NS3 protease. Additionally, chemical and biological systems are commonly studied using molecular modeling approaches allowing, among several other processes, to elucidate mechanisms of action, molecule reactivity and/or chemical properties and the design of new drugs. Thus, considering the in silico complexes between the biological target and the bioactive molecule, it is possible to understand better experimental results based on molecular properties, which are compared with the findings of the biological activity. Accordingly, this study aimed to present computational docking simulations of five previously reported active peptides against NS2B-NS3 protease of ZIKV and analyze some quantum chemical properties to identify the main contribution to improving the action. The compounds were described by Rut and coworkers (2017) and Hill and coworkers (2018), submitted to docking simulation in Gold software and quantum chemical properties calculations in Wavefunction Spartan software. Total energy, electrophilicity index (ω) and energy gap (GAP) appeared to be the best properties to justify the peptide's biological activity. Moreover, the most promising compound (P1, Km 4.18 μM) had the best value of total energy (- 2763.04001 au), electrophilicity index (8.04 eV) and GAP (6.49 eV), indicating an energetically favorable molecule with good interaction with the target and, when compared to other peptides, presented moderate reactivity. P4 showed the highest electrophilicity index value (28.64 eV), which justified the interaction ability visualized in the docking simulation. However, its GAP value (4.24 eV) was the lowest in the series, suggesting high instability, possibly validating its low biological activity value (Km 19 uM). GAP was important to understand the chemical instability, and high values can promote damage to biological response. Furthermore, it was also noted that high electron affinity, related to the electrophilicity index, promoted electron-accepting characteristics, which was important to improve the biological activity of the peptides. A larger compound series must be studied to access features more precisely. However, these results have paramount importance in guiding future effort in this extremely-need health area.

A review of vectors, vector borne diseases, vector control and their impact on public health

Mosquitoes are most important insect vectors for human disease transmission. Dengue, yellow fever, chikungunya, and zika are all spread by Aedes mosquitoes in many parts of the world. The primary vector of human malaria transmission is Anopheles. Culex is responsible for the transmission of Japanese encephalitis, lymphatic filariasis and West Nile virus fever. Synthetic pesticides have been successfully utilized in mosquito-control programmes for several decades. However, there are a number of disadvantages to the chemical method. As a result, there has been a rise in concern in the usage of biological agents for mosquito control in recent years. Because of their highly effective mosquitocidal activity, Bacillus sphaericus and Bacillus thuringiensis israelensis have been utilized extensively. While insecticide-based interventions have successfully reduced mosquito populations for a number of years, the reliance on a few number of insecticides has now led to the evolution of resistance. So there is a need to search for novel mosquitocidal bacteria for control the mosquito species. Since soil is one of the world's most diversified environments in which bacteria and fungi are abundant, screening of soil samples for isolation of novel mosquitocidal bacteria is attempted.

Mosquito-borne diseases, their impacts and mosquito vector control methods - A review

Vector borne diseases are increasing nowadays and can spread to new locations easily. Diseases like zika virus fever, West Nile fever, malaria, yellow fever, Japanese encephalitis, dengue, etc. are examples of mosquito-borne diseases. These diseases are majorly caused by three species of mosquitoes Anopheles, Aedes, and Culex. Most mosquito vector control methods depend upon outdoor spraying, impregnated nets, or indoor residual spraying of chemical insecticides and it was observed that many mosquito species evolved resistance to major pesticide classes. The disadvantages of using chemical pesticides are the development of resistance in mosquitoes and also the harm it causes to other non-target organisms, in addition to the higher cost, more labor, and other drawbacks. Using DEET is also not as preferable as it can induce muscle twitching, seizures, slurred speech, nausea, and rashes. DEET will not give long-term protection against all malaria-causing mosquito species, such as Anopheles. Whereas biocontrol agents used for mosquito control show no environmental pollution or resistance. Bacillus thuringiensis israelensis and Bacillus sphaericus biopesticides tend to remain longer in the environment, particularly in dirty water, and hence may be a viable choice for long-term mosquito control. They have the least adverse effect on living things like humans, domestic animals, and wildlife.

Dual-fluorescent reporter for live-cell imaging of the ER during DENV infection.

Infection by flaviviruses leads to dramatic remodeling of the endoplasmic reticulum (ER). Viral replication occurs within virus-induced vesicular invaginations in the ER membrane. A hallmark of flavivirus infection is expansion of the ER membrane which can be observed at specific time points post infection. However, this process has not been effectively visualized in living cells throughout the course of infection at the single cell resolution. In this study, we developed a plasmid-based reporter system to monitor flavivirus infection and simultaneous virus-induced manipulation of single cells throughout the course of infection in real-time. This system requires viral protease cleavage to release an ER-anchored fluorescent protein infection reporter that is fused to a nuclear localization signal (NLS). This proteolytic cleavage allows for the translocation of the infection reporter signal to the nucleus while an ER-specific fluorescent marker remains localized in the lumen.Thus, the construct allows for the visualization of virus-dependent changes to the ER throughout the course of infection.In this study, we show that our reporter was efficiently cleaved upon the expression of multiple flavivirus proteases, including dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV).We also found that the DENV protease-dependent cleavage of our ER-anchored reporter exhibited more stringent cleavage sequence specificity than what has previously been shown with biochemical assays. Using this system for long term time-lapse imaging of living cells infected with DENV, we observed nuclear translocation of the reporter signal beginning approximately 8 hours post-infection, which continued to increase throughout the time course.Interestingly, we found that increased reporter signal translocation correlated with increased ER signal intensity, suggesting a positive association between DENV infection and ER expansion in a time-dependent manner. Overall, this report demonstrates that the FlavERplatform provides a useful tool for monitoring flavivirus infection and simultaneously observing virus-dependent changes to the host cell ER, allowing for study of the temporal nature of virus-host interactions.

Development of gold Immunochromatographic assay strip based on specific polyclonal antibodies against capsid protein for rapid detection of porcine circovirus 2 in Zhejiang province, China

BackgroundThe existing detection methods for porcine circovirus type 2 (PCV2) specific antibodies in serum cannot determine the infection status, thus it is necessary to establish a method for detecting PCV2 antigen. The capsid protein (CAP) of PCV2, as a major structural protein that plays a significant role in viral replication and in inducing host’s immune response, is an ideal target antigen to monitor PCV2 infection. Therefore, a gold immunochromatographic assay (GICA) for rapid detection of PCV2 antigen based on the polyclonal antibodies (PAbs) against PCV2-CAP will be developed.ResultsThe truncated CAP protein (dCAP) was used to immunize rabbits to generate anti-serum. After preliminary purification by caprylic acid/ammonium sulfate precipitation (CAAS), specific PAbs were purified by affinity chromatography column coupled with dCAP and its titer was about two-fold higher than preliminary purified PAbs. Colloidal gold-PAbs conjugate was synthesized under the optimum conditions. The specific anti-dCAP PAbs and goat anti-rabbit antibody (GAR) were then sprayed onto nitrocellulose (NC) membrane as a test line (TL) and a control line (CL), respectively. The visual limit detection (vLOD) of the GICA strips was 5 ng/mL. Specificity assay indicated that the GICA strips had specifically detected PCV2 and was not reactive for porcine epidemic diarrhea virus (PEDV), pseudorabies virus (PRV), porcine reproductive and respiratory syndrome virus (PRRSV) or classic swine fever virus (CSFV). A total of 36 porcine serum samples were detected by this GICA and commercial enzyme-linked immunosorbent assay (ELISA) Kit, 9 positive samples were found by the developed strip with the rate of 25.0% comparing with 11 positive samples detected by the commercially ELISA Kit which positive rate was 30.5%, and the receiver operating characteristic (ROC) curve revealed that the relative sensitivity and specificity of this GICA strip were 72.7 and 96.0%, respectively, with an area of 87.2%.ConclusionsThis study established an efficient detection method with high sensitivity and specificity for the clinical diagnosis of PCV2 antigen, that will facilitate a rapid and convenient way to evaluate the infection status of vaccinated pigs.

Common pathways targeted by viral hemorrhagic fever viruses to infect the placenta and increase the risk of stillbirth

Viral hemorrhagic fevers (VHF) are endemic to Africa, South America and Asia and contribute to significant maternal and fetal morbidity and mortality. Viruses causing VHFs are typically zoonotic, spreading to humans through livestock, wildlife, or mosquito vectors. Some of the most lethal VHF viruses also impart a high-risk of stillbirth including ebolaviruses, Marburg virus (MARV), Lassa virus (LASV), and Rift Valley Fever Virus (RVFV). Large outbreaks and epidemics are common, though the impact on the mother, fetus and placenta is understudied from a public health, clinical and basic science perspective. Notably, these viruses utilize ubiquitous cellular surface entry receptors critical for normal placental function to enable viral invasion into multiple key cell types of the placenta and set the stage for maternal-fetal transmission and stillbirth. We employ insights from molecular virology and viral immunology to discuss how trophoblast expression of viral entry receptors for VHF viruses may increase the risk for viral transmission to the fetus and stillbirth. As the frequency of VHF outbreaks is expected to increase with worsening climate change, understanding the pathogenesis of VHF-related diseases in the placenta is paramount to predicting the impact of emerging viruses on the placenta and perinatal outcomes.