Detection Of Viral Antigens Research Articles

An HIV Diagnostic Testing Algorithm Using the cobas HIV-1/HIV-2 Qualitative Assay for HIV Type Differentiation and Confirmation.

ABSTRACTHuman immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) diagnostic testing algorithms recommended by the Centers for Disease Control involve up to three tests and rely mostly on detection of viral antigen and host antibody responses. HIV-1 p24 antigen/HIV-1/HIV-2 antibody-reactive specimens are confirmed with an immunochromatographic HIV-1/HIV-2 antibody differentiation assay, and negative or indeterminate results from the differentiation assay are resolved by an HIV-1-specific nucleic acid amplification test (NAT). The performance of a proposed alternative algorithm using the cobas HIV-1/HIV-2 qualitative NAT as the differentiation assay was evaluated in subjects known to be infected with HIV-1 (n = 876) or HIV-2 (n = 139), at low (n = 6,017) or high (n = 1,020) risk of HIV-1 infection, or at high-risk for HIV-2 infection (n = 498) (study A). The performance of the cobas HIV-1/HIV-2 qualitative test was also evaluated by comparison to an HIV-1 or HIV-2 alternative NAT (study B). The HIV-1 and HIV-2 overall percent agreements (OPA) in study A ranged from 95% to 100% in all groups. The positive percent agreements (PPA) for HIV-1 and HIV-2 were 100% (876/876) and 99.4% (167/168), respectively, for known positive groups. The negative percent agreement in the HIV low-risk group was 100% for both HIV-1 and HIV-2. In study B, the HIV-1 and HIV-2 OPA ranged from 99% to 100% in all groups evaluated (n = 183 to 1,030), and the PPA for HIV-1 and HIV-2 were 100% and 99.5%, respectively, for known positive groups. The cobas HIV-1/HIV-2 qualitative assay can discriminate between HIV-1 and HIV-2 based on HIV RNA and can be included in an alternative diagnostic algorithm for HIV.

Paper-Based Biosensors: Frontiers in Point-of-Care Detection of COVID-19 Disease.

This review summarizes the state of the art of paper-based biosensors (PBBs) for coronavirus disease 2019 (COVID-19) detection. Three categories of PBB are currently being been used for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics, namely for viral gene, viral antigen and antibody detection. The characteristics, the analytical performance, the advantages and drawbacks of each type of biosensor are highlighted and compared with traditional methods. It is hoped that this review will be useful for scientists for the development of novel PBB platforms with enhanced performance for helping to contain the COVID-19 outbreak, by allowing early diagnosis at the point of care (POC).

DENGUE FEVER: CLINICO-PATHOLOGICAL CORRELATION WITH SEROLOGICAL MARKERS AND PLATELET COUNT

Dengue is an acute viral illness caused by RNA virus of the family Flaviviridae and spread by Aedes mosquitoes. Presenting features may range from asymptomatic fever to dreaded complications such as hemorrhagic fever and shock. A decreased number of white blood cells (leukopenia) accompanied by a decreased number of platelet count (thrombocytopenia) and metabolic acidosis are the initial changes on laboratory examinations. Microbiological laboratory testing conrms the diagnosis of Dengue Fever. Virus segregation in cell cultures, nucleic acid demonstration by polymerase chain reaction (PCR), and serological detection of viral antigens (such as NS1) or particular antibodies are the preferred microbiological assays. This study focuses on the importance of platelet counts and other platelet parameters in dengue infection. Also platelet counts are compared with clinical, radiological and other serological markers.

Do Pruritus and Urticaria Predict For Response to Antihistamine Therapy in COVID-19 Patients with Pulmonary Symptoms?

Dear Editor,
 Skin manifestations and respiratory symptoms are commonly seen in patients with COVID-19. While infection by SARS-CoV-2 and an accompanying cytokine storm are proposed to account for respiratory symptoms, additional inflammatory mediators including histamine may also contribute. In this regard, we report the resolution of dyspnea associated with urticaria in a 61-year-old female patient acutely infected with SARS-CoV-2. The patient’s medical history is significant for idiopathic thrombocytopenic purpura, hypertension, and gastroesophageal reflux disease, and her long-standing medications consisted of eltrombopag, hydrochlorothiazide, lisinopril, and pantoprazole. The patient had no prior history of urticaria, angioedema, or respiratory illness. Due to the severity of her symptoms which developed over the course of a few days, the patient was referred to an urgent care clinic where intravenous methylprednisolone was administered, and tapering doses of prednisone were prescribed starting at 50mg. Nevertheless, all of her symptoms, particularly the urticaria (Figure 1 a,b), continued to worsen, prompting her to visit our dermatology clinic where she was started on hydroxyzine 25mg q.d. and topical triamcinolone acetonide 0.1%. A first-generation antihistamine was selected to address both pruritus and associated insomnia. Additionally, prednisone was discontinued as there was no response to the medication. The patient experienced relief of urticaria within 4 hours after starting hydroxyzine and reported improvement of her dyspnea by the following morning. A SARS-CoV-2 test performed at the urgent care clinic was positive for the detection of viral antigen. The patient’s symptoms completely resolved within 5 days after initiating hydroxyzine. The signs and symptoms of mast cell activation including urticaria and pruritus and response to antihistamines suggest that mast cells and their chemical mediators play a significant role in the pathophysiology of some COVID-19 patients. While case reports have described improvement of urticaria and other mast cell-mediated symptoms in COVID-19 patients following the administration of antihistamines, these cases were co-founded by the concomitant addition of new medications; this issue is less relevant in our report.1
 Urticaria is a common dermatologic manifestation of COVID-19 patients, with an incidence of 19% in a prospective study of 375 patients.2 No correlation between urticaria and disease severity, or timing of onset has been described.3 Possible etiologies of urticaria in COVID-19 patients include a reaction to viral infection, medications, and stress. The SARS-CoV-2 virus itself may directly activate mast cells via toll-like receptors or signaling molecules such as interferon type 1, TNF-α, and/or chemokines.4 It is thought that mast cell degranulation may either be caused directly by the virus or indirectly through viral stimulation of complement fragments C3a and C5a activating G-protein-coupled receptors.4
 While cytokine storms, and more recently, bradykinin storms, are proposed as mediators in the pathophysiology of COVID-19, mast cells and histamine may also contribute to the development of pulmonary manifestations of COVID-19 patients.5 The clinical course of our patient indicates her respiratory symptoms appeared solely related to SARS-CoV-2 induced urticaria. Release of histamine, prostaglandin-D2, and leukotriene-C4 by mast cells cause bronchoconstriction.6 Further, the release of mast cell cytokines such as IL-1 and IL-6 contribute to the development of pulmonary and systemic inflammation, as well as urticaria in COVID-19 patients.3,4,6,7 Preliminary clinical trial reports suggest antihistamine treatment mitigates pulmonary symptoms in COVID-19 patients. Trials of dual-histamine receptor blockade with cetirizine-famotidine in hospitalized COVID-19 patients with severe pulmonary symptoms resulted in marked reductions in rates of intubation, mortality, and length of hospital stay.8 Additionally, a retrospective study of 1,620 COVID-19 patients who received the H2 receptor antagonist famotidine, showed a statistically significant reduction in the rates of intubation and death.9
 Based on the observations that urticaria and pruritus may accompany pulmonary symptoms, we postulate these patients may better respond to antihistamine therapy. Therefore, we suggest these dermatologic findings are incorporated into the analysis plans of clinical studies assessing antihistamines in COVID-19 patients with pulmonary symptoms. Further, we suggest considering antihistamines as a component of the first-line treatment for COVID-19 patients with urticaria.

Rapid SARS-CoV-2 antigen detection potentiates early diagnosis of COVID-19 disease.

As the COVID-19 epidemic is still ongoing, a more rapid detection of SARS-CoV-2 infection such as viral antigen-detection needs to be evaluated for early diagnosis of COVID-19 disease. Here, we report the dynamic changes of SARS-CoV-2 viral antigens in nasopharyngeal swabs of COVID-19 patients and its association with the viral nucleic acid clearance and clinical outcomes. Eighty-five COVID-19 patients were enrolled for detection of SARS-CoV-2 viral antigens, including 57 anti-SARS-CoV-2 antibody negative cases and 28 antibody positive cases. The viral antigen could be detected in 52.63% (30/57) patients with SARS-CoV-2 antibody negative at the early stage of SARS-CoV-2 infection, especially in the first 5 days after disease onset (p = 0.0018) and disappeared in about 8 days after disease onset. Viral antigens were highly detectable in patients with low Ct value (less than 30) of SARS-CoV-2 nucleic acid RT-PCT assay, suggesting the expression of viral antigen was associated with high viral load. Furthermore, positive antigen detection indicated disease progression, nine cases with positive antigen (9/30, 30.0%), in contrast to two cases (2/27, 7.40%) (p = 0.0444) with negative antigen, which progressed into severe disease. Thus, the viral antigens were persistent in early stages of infection when virus was in highly replicating status, and viral antigen detection promises to rapidly screen positive patients in the early stage of SARS-CoV-2 infection.

Viral tropism and detection of clade 2.3.4.4b H5N8 highly pathogenic avian influenza viruses in feathers of ducks and geese

Highly Pathogenic Avian Influenza viruses (HPAIVs) display a tissue pantropism, which implies a possible spread in feathers. HPAIV detection from feathers had been evaluated for H5N1 or H7N1 HPAIVs. It was suggested that viral RNA loads could be equivalent or higher in samples of immature feather compared to tracheal (TS) or cloacal swabs (CS). We investigated the suitability of feathers for the detection of clade 2.3.4.4b H5N8 HPAIV in ducks and geese field samples. In the six H5N8 positive flocks that were included in this study, TS, CS and immature wing feathers were taken from at least 10 birds. Molecular loads were then estimated using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) targetting H5 and M genes. In all flocks, viral loads were at least equivalent between feather and swab samples and in most cases up to 103 higher in feathers. Bayesian modelling confirmed that, in infected poultry, RT-qPCR was much more likely to be positive when applied on a feather sample only (estimated sensitivity between 0.89 and 0.96 depending on the positivity threshold) than on a combination of a tracheal and a cloacal swab (estimated sensitivity between 0.45 and 0.68 depending on the positivity threshold). Viral tropism and lesions in feathers were evaluated by histopathology and immunohistochemistry. Epithelial necrosis of immature feathers and follicles was observed concurrently with positive viral antigen detection and leukocytic infiltration of pulp. Accurate detection of clade 2.3.4.4b HPAIVs in feather samples were finally confirmed with experimental H5N8 infection on 10-week-old mule ducks, as viral loads at 3, 5 and 7 days post-infection were higher in feathers than in tracheal or cloacal swabs. However, feather samples were associated with lower viral loads than tracheal swabs at day 1, suggesting better detectability of the virus in feathers in the later course of infection. These results, based on both field cases and experimental infections, suggest that feather samples should be included in the toolbox of samples for detection of clade 2.3.4.4b HPAI viruses, at least in ducks and geese.

JMM Profile: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is the cause of an infection known as coronavirus infectious disease 2019 (COVID-19). COVID-19 has become a global source of morbidity, mortality and social disruption since its emergence in East Asia in late 2019 and subsequent pandemic spread. Typical symptoms include cough, sore throat, fever, and sudden loss of taste and smell. Persistent, post-infection sequelae have been noted in a minority of cases. Severe complications and deaths occur mostly in older adults. Laboratory confirmation can be performed by viral RNA and antigen detection in nasal swabs or by detecting specific neutralizing antibodies. There is no effective and approved antiviral treatment, but several vaccines with favourable safety and efficacy profiles are being used in mass vaccination programmes. Vaccine-based COVID control should be seen as an addition to existing hygiene measures such as physical distancing, increased hand hygiene, cough etiquette, and barrier protection with personal protective equipment for frontline healthcare workers and other high-risk professions.

A reassortant G3P[12] rotavirus A strain associated with severe enteritis in donkeys (Equus asinus)

In contrast to horses, the only evidence suggesting gastrointestinal disease in neonatal donkeys is associated with Group A rotaviruses (RVAs) is the detection of viral antigens by ELISA in just 1 of 82 symptomatic donkey foals. No additional, more comprehensive investigations have been conducted, and RVAs if circulating in donkey populations have not been molecularly characterised. To investigate if RVAs are associated with an outbreak of severe enteritis in neonatal donkeys and if associated determine the genotype(s) along with the phylogenetic relationship to RVA strains circulating in horses. Cross-sectional. RT-PCR-based techniques were used for RVA diagnosis and gene amplification. Statistical significance was determined by Chi-square and Fisher's exact two-sided tests. Genotyping was performed by RotaC and phylogenetic analysis by neighbour joining. In 2019, acute enteritis occurred in 119 of 206 donkey foals (≤4months) at two intensive donkey farms in the Shandong province of China. The highest morbidity (68.1%), mortality (29.5%) and fatality levels (45.5%) occurred in foals in the 30-89day, 30-59day and 0-29day age groups respectively. RVA gene sequences were detected in 107 (89.9%) of the symptomatic individuals while further analysis demonstrated the outbreak was associated with the same G3P[12] RVA strain designated RVA/Donkey-wt/CHN/Don01/2019/G3P[12]. Although the VP4 gene of Don01 exhibited close phylogenetic relationships with equivalent RVA sequences commonly circulating in horses, encoding VP7 was more closely associated with sequences isolated from bats suggesting this new donkey strain arose via an intergenogroup reassortment event. Actual prevalence not determined because <7% of asymptomatic donkey foals were included in this study. The complete genomic sequence of RVA/Donkey-wt/CHN/Don01/2019/G3P[12] remains to be determined. Valuable new information about the molecular epidemiology of rotaviruses in different equid species is provided by isolation and molecular characterisation of a novel RVA strain from neonatal donkeys.

Detection of varicella zoster virus antigen and DNA in two cases of cerebral amyloid angiopathy

ObjectiveVaricella zoster virus (VZV) vasculopathy and cerebral amyloid angiopathy (CAA) have similar clinical presentations: both affect cerebrovasculature in the elderly, produce hemorrhage, and can have a protracted course of cognitive decline and other neurological deficits. The cause of CAA is unknown, but amyloid-beta (Aβ) is found within arterial walls. Recent studies show that VZV induces Aβ and amylin expression and an amyloid-promoting environment. Thus, we determined if VZV was present in CAA-affected arteries. MethodsTwo subjects with pathologically-verified CAA were identified postmortem and frontal lobes analyzed by immunohistochemistry for arteries containing VZV, Aβ, and amylin and H&E for pathological changes. VZV antigen detection was confirmed by PCR for VZV DNA in the same region. ResultsIn both CAA cases, sections with cerebral arteries containing VZV antigen with corresponding VZV DNA were identified; VZV antigen co-localized with Aβ in media of arteries with histological changes characteristic of CAA. Amylin was also seen in the intima of a VZV-positive artery in the diabetic subject. Not all Aβ-containing arteries had VZV, but all VZV-positive arteries contained Aβ. ConclusionsVZV antigen co-localized with Aβ in some affected arteries from two CAA cases, suggesting a possible association between VZV infection and CAA.

Investigations into Foot and Mouth Disease Outbreak among Small Ruminants in Karnataka State of India

Background: Foot-and-Mouth Disease (FMD) remains a serious threat to the Indian livestock sector due to significant economic loss associated with it. Systematic vaccination of large ruminants over the years has lead to a gradual reduction in the number of disease outbreaks in India. However exposure to FMDV infection in small ruminants has been recorded during the past few years (Rout et al. 2013). Sheep and goat population have not been vaccinated so far against FMD under the FMD-Control program (FMD-CP). The present study highlighted the outbreak of FMD in small ruminants in Karnataka, India.Methods: During the period 2018-19, seven suspected FMD outbreaks among sheep population in Bellary and Tumakuru districts of Karnataka state were investigated. Tongue epithelium (oral swabs) and foot lesions (n=23) from clinically affected sheep and tissues such as heart, lung, liver, spleen, lymph nodes and kidneys from lambs during post mortem (n=67) were collected. All the samples were processed in the laboratory for the detection of FMD virus antigen by employing Serotype differentiating antigen detection ELISA and by multiplex PCR. Heart tissue samples were also collected in buffered formalin for histopathology study and processed by routine paraffin embedding technique and stained with Hematoxylin and Eosin (H and E). Serum samples from the recovered animals were collected and screened by NSP-ELISA and LPB-ELISA to check the antibody status in the affected herd. Result: A total of seven suspected outbreaks of FMD involving 688 small ruminants was investigated. The outbreak of FMD due to FMDV serotype O was confirmed by ELISA and multiplex PCR assays. Clinically, the affected adult sheep showed typical signs of FMD, while mortality in young lambs was observed without apparent signs of disease. Histologically, heart tissues from FMD affected lambs showed myocardial necrosis with marked aggregations of lymphocytes and neutrophils in the myocardium and perivascular spaces. History of FMD outbreaks in cattle and common grazing land for the livestock, as well as sheep within the reach of these villages, may be the major contributing factors for the outbreaks in sheep populations.

Viral antigen detection in blood (Serum) has no role in laboratory diagnosis of rabies

Viral antigen detection in blood (Serum) has no role in laboratory diagnosis of rabies

Immunohistochemical detection of virus antigen in the nasal planum of rabid dogs

The rabies virus is one of the most neurotropic of all viruses infecting mammals. During the terminal phases of infection, the virus spreads to peripheral tissues, including the skin. The external skin of the nose, called the nasal planum, is a sensory organ where numerous nerve bundles and terminal nerves are distributed. Therefore, the nasal planum is expected to serve as a postmortem diagnostic material. However, the distribution of rabies virus antigens in the nasal planum in rabid animals has not yet been studied. In this study, the nasal planum was obtained from 45 rabid dogs. In all rabid dogs, the viral antigen was detected in the peripheral nerve tissues, Merkel cells, and squamous cells. The viral antigen in the epidermis exhibited three patterns: first, a diffuse positive pattern from the basal layer to the squamous layer; second, a reticular positive pattern along the cell membrane in the squamous layer; and third, a basal layer pattern of the epidermis. In the dermis, viral antigens were detected more often in lamellated corpuscles just beneath the rete pegs. These results suggest that the nasal planum could serve as a useful alternative source for postmortem diagnosis in rabies endemic countries.

Vector Surveillance for Dengue, Chikungunya, Zika Virus and Yellow Fever at Three Blocks of Pakur Districts of Jharkhand, India

Vector borne diseases are a major public health problem in India. Dengue is endemic in almost all states and union territories. Aedes mosquitoes are known to transmit Dengue, Chikungunya, Zika virus and Yellow fever diseases to man in both rural and urban areas. Dengue has been restricted to urban area, but it has now spread to rural and tribal areas. An entomological survey was undertaken at selected villages of three Blocks of Pakur district i.e. Pakur, Maheshpur and Amarpada of Jharkhand to know the potential for the transmission of Dengue/Chikungunya, Zika virus and Yellow fever and thereby undertaking surveys of breeding places of the vector species in these area by assessing the vector indices i.e. House Index (HI), Breteau Index (BI) and Container Index (CI) along with virus antigen detection. The entomological indices of G aneshpura, Datiapokhar and Longbahra villages of Maheshpur block recorded very high i.e. HI-28.5, 15.0 &amp; 10.0; BI-34.2, 15.0 &amp; 10.0 and CI-11.8, 8.8 &amp; 4.8 respectively. The entomological indices of Pakur block, villages Jamsherpur, Malipada and Gopinathpur showed HI-7.3, 3.3 &amp; 2.3; BI-7.3, 3.3 &amp; 2.3 and CI-3.5, 1.5 &amp; 1.3 respectively. The entomological indices of Amarpada block, villages-Jagjitpur, Ambajora and Pakudh showed HI-6.6, 0.0 &amp; 0.0; BI-6.6, 0.0 &amp; 0.0; and CI-2.5, 0.0 &amp; 0.00 respectively. However, surveys revealed highest vector indices at Maheshpur block, followed by Pakur block and Amarpada block. Local health authorities of Maheshpur, Pakur and Amarpada blocks need to take cognizance of these facts with the presence of breeding potential areas and to develop micro action plan for appropriate vector control measures along with vector surveillance on regular basis.

Герпесвирусы. Часть 1

One of the urgent problems of modern medicine is the high incidence of herpesvirus infections. The high prevalence of herpesviruses in the human population of the world allow us to consider herpes a common systemic disease of the whole organism. Doctors of any specialty are faced with the clinical manifestations of herpes infection in patients, and they themselves are a risk group of chronic herpes infections formation due to constant patient contacts and frequent professional psycho-emotional overload. Herpes infections are a group of infectious diseases caused by human herpesviruses. Now it is known 8 species of herpesvirus causing various human diseases that occur in the acute (during the initial contact with the infection) or chronic form. The herpesvirus family has a number of common properties that distinguish them from other human pathogenic viruses. There are three subfamilies in the Herpesviridae family. Alpha herpesviruses (Аlphaherpesvirinae) include the two serotypes of the herpes simplex virus (HSV-1 and HSV-2), and the varicella-zoster virus (herpes zoster). Beta herpesviruses (Betaherpesvirinae) include cytomegalovirus, human herpes viruses of types 6 and 7 (HHV-5, HHV-6, HHV-7). Gamma herpes viruses (Gammaherpesvirinae) include the Epstein-Barr virus, human herpesvirus type 8 (HHV-4, HHV-8). Clinical manifestations of herpes infection depend more on the immunity state of the infected organism than on the pathogenic properties of the pathogen itself, and develop only in conditions of immunodeficiency caused by various unfavorable factors. Herpesviruses are able to damage organs, weaken the body's immunity, creating conditions for the attachment of the other infections (fungal, bacterial), which in turn can cause organ damage. The herpesvirus ability to infect all organs and tissues of the body determines a significant clinical polymorphism of diseases, as well as the necessity to study various biological liquids. Herpesviruses can be transmitted from person to person by aerosol, contact, sexual and parenteral transmission, as well as from mother to fetus or newborn, they also can act as mutagens. The pathogenesis of herpesvirus infections is rather complex and not completely understood. For a proper understanding of the disease pathogenesis it is necessary to know the main stages of reproduction of human herpesviruses. Modern laboratory techniques are used for diagnosis of herpes infection and allow obtaining more complete information for an accurate diagnosis: virological method, electron microscopy method, the method of biological sample, the polymerase chain reaction methods for the detection of viral antigens, serological, immunological, cytological and histological methods. Conclusion. The high prevalence of diseases caused by herpes viruses, the complex, not fully understood pathogenesis and high contagiousness of diseases, as well as a variety of clinical manifestations of herpesvirus infections with the possibility of the formation of mixed forms with a blurred clinical picture dictate the need for a detailed study of herpes viruses and knowledge of methods for diagnosing herpes infections

CELL CULTURE AS THE MOST CERTAIN WAY OF DIAGNOSIS IN RABIES INFECTION

Rabies is a zoonotic disease that causes progressive and fatal inflammation of the brain and spinal cord. This disease is still widespread in the world and is a social and economic burden in many countries. Rabies is estimated to cause 60.000 human deaths annually in over 150 countries, with 95% of cases occurring in Africa and Asia. Several countries in Southeast Asia, including Indonesia, have become one of the endemic areas for rabies. The diagnosis of rabies infection in animals and humans can be made by histopathology, virus cultivation, serology, and virus antigen detection This paper discusses cell culture as a method in the diagnosis of rabies. This paper is a literature review through a literature search in scientific journals and research reports that explains the various studies on the isolation of Rabies virus in cell culture, cell types used, and the technique in diagnosing Rabies infection in cell culture. The diagnosis of rabies can be made by neuroblastoma cells, BHK-21 cell lines, HEK-293 cell lines, and others. It can be concluded that the diagnosis of Rabies virus can be done on several cell lines and needs to be followed by other tests. The nature of rabies disease dictates that laboratory tests be standardized, rapid, sensitive, specific, economical, and reliable.

Brote de rabia paresiante bovina en la región libre de enfermedad en la Argentina

We report an outbreak of bovine paralytic rabies in a feed lot in a disease-free area in southern Santa Fe, Argentina. Six of 122 unvaccinated steers died after showing neurological signs (morbimortality = 4.9%) for 24-72 hours, 40-75 days after being transported to the feed lot from a farm located in Formosa. Pathologic examination of the brain in 3 steers revealed gliosis, lymphoplasmacytic meningoencephalitis, and intracytoplasmic inclusion bodies in neurons, along with intralesional detection of the rabies virus antigen by immunohistochemistry in 2 cases. Rabies virus was confirmed by direct immunofluorescence in the brain, and further identified as variant 3a, typical of hematogenous bats, by inoculation in mice followed by indirect immunofluorescence. This represents the first communication of bovine paralytic rabies described in the Pampas plain in Argentina, and evidences that the transport of cattle from endemic to disease-free areas could represent a mechanism of dissemination of this communicable zoonotic disease.

COVID-19: Understanding the Pandemic Emergence, Impact and Infection Prevalence Worldwide

Coronavirus disease (COVID-19) has showed high transmission across the continents due to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) with total infected cases of around ~ 44 million people. This communicable virus that initiated from the Wuhan city of China in the month of December 2020 has now spread to 189 different countries with 1.1 million fatalities worldwide (till 28 Oct, 2020). The World Health Organization (WHO) declared this outbreak as Public Health Emergency of International Concern in January, 2020. The infection spreads mainly due to contact with infected droplets or fomites, highlighting flu like symptoms initially, which may further progress into severe pneumonia and respiratory failure, often observed in elderly patients with prehistory of other diseases. The diagnosis is based on detection of viral antigen, human antibody and viral gene (RT-PCR). Further, various other diagnostic tools including X-ray, CT-scan are used for imaging purpose, recently artificial intelligence based imaging (contactless scanning) gained popularity. Generally testing of existing drugs (repurposing) and development of new molecules are the main strategies adopted by researchers. However, as per initial findings, various drugs, monoclonal antibody and plasma therapy were found to show effectiveness against COVID-19. Further, many vaccine candidates have entered or will soon enter phase III clinical testing. This disease has further challenged the global economy. Thus, this review uniquely compares the strategies adopted by developed and developing countries worldwide including protective measures like lockdown, continuous testing, utilizing latest tools (artificial intelligence) in curbing this infection spread.

Cytometry Multiplex Bead Antibody Array.

The flow cytometry-based multiplex bead array is an advanced technology using antibody-conjugated multiplex beads to detect soluble targets in a liquid phase. This technology has been widely used for detection of soluble analytes like cytokines, chemokines, allergens, viral antigens, and cancer markers. RayPlex® Multiplex Beads Antibody Array series are developed by RayBiotech Life, Inc. to quantitatively detect a wide range of analytes with high sensitivity to meet increasing need of research and diagnosis.

Immunodominant regions prediction of nucleocapsid protein for SARS-CoV-2 early diagnosis: a bioinformatics and immunoinformatics study

ABSTRACT COVID-19 caused by SARS-CoV-2 is sweeping the world and posing serious health problems. Rapid and accurate detection along with timely isolation is the key to control the epidemic. Nucleic acid test and antibody-detection have been applied in the diagnosis of COVID-19, while both have their limitations. Comparatively, direct detection of viral antigens in clinical specimens is highly valuable for the early diagnosis of SARS-CoV-2. The nucleocapsid (N) protein is one of the predominantly expressed proteins with high immunogenicity during the early stages of infection. Here, we applied multiple bioinformatics servers to forecast the potential immunodominant regions derived from the N protein of SARS-CoV-2. Since the high homology of N protein between SARS-CoV-2 and SARS-CoV, we attempted to leverage existing SARS-CoV immunological studies to develop SARS-CoV-2 diagnostic antibodies. Finally, N229-269, N349-399, and N405-419 were predicted to be the potential immunodominant regions, which contain both predicted linear B-cell epitopes and murine MHC class II binding epitopes. These three regions exhibited good surface accessibility and hydrophilicity. All were forecasted to be non-allergen and non-toxic. The final construct was built based on the bioinformatics analysis, which could help to develop an antigen-capture system for the early diagnosis of SARS-CoV-2.

COVID-19 diagnosis —A review of current methods

A fast and accurate self-testing tool for COVID-19 diagnosis has become a prerequisite to comprehend the exact number of cases worldwide and to take medical and governmental actions accordingly. SARS-CoV-2 (formerly, 2019-nCoV) infection was first reported in Wuhan (China) in December 2019, and then it has rapidly spread around the world, causing ~14 million active cases with ~582,000 deaths as of July 2020. The diagnosis tools available so far have been based on a) viral gene detection, b) human antibody detection, and c) viral antigen detection, among which the viral gene detection by RT-PCR has been found as the most reliable technique. In this report, the current SARS-CoV-2 detection kits, exclusively the ones that were issued an “Emergency Use Authorization” from the U.S. Food and Drug Administration, were discussed. The key structural components of the virus were presented to provide the audience with an understanding of the scientific principles behind the testing tools. The methods that are still in the early research state were also reviewed in a subsection based on the reports available so far.