Elimination of PRRS Using An Inactivated Vaccine in Combination With A Roll-Over Method in A Hungarian Large-Scale Pig Herd

2021 ◽  
Author(s):  
Attila Pertich ◽  
Zoltán Barna ◽  
Orsolya Makai ◽  
János Farkas ◽  
Tamás Molnár ◽  
...  
Keyword(s):  
Large Scale ◽  
Serological Test ◽  
Clinical Signs ◽  
Competent Authority ◽  
Economic Losses ◽  
Complex Method ◽  
Inactivated Vaccine ◽  
Eradication Programme ◽  
Serological Tests ◽  
Offspring Production

Abstract Background:Four countries are free from the porcine reproductive and respiratory syndrome virus (PRRSV) in Europe, a virus that causes severe economic losses worldwide. A number of countries have initiated eradication programmes against the disease. Among the applied methods, complete depopulation-repopulation is the safest and fastest but at the same time the most expensive process. Another possible way of heard eradication is to replace the infected breading stock by gilts reared PRRSV free on the infected farm. This way maintaining continued farm production. In this paper, the authors present a successful complex method of eradication (including the application of an inactivated vaccine and segregated rearing of offspring) in a Hungarian large scale pig farm. Case presentation:A farm of 1475 sows (Farm A) was infected with PRRSV and the clinical signs of reproductive failure were eliminated by using an inactivated vaccine (Progressis®, Ceva). At the beginning of eradication, gilts selected for breeding were vaccinated at 60 and 90–100 days of age, respectively. The subsequent vaccinations of breeding animals were applied at 6 months of age, on the 60–70th day of pregnancy and at weaning. The 7weeks-old piglets of the vaccinated sows, approximately 1200 piglets were transported in groups of 300 animals to a closed, empty farm (Farm B) after a testing negative with PCR, and they were reared here until 14 weeks of age. These seronegative gilts were subsequently transported to a third, closed, empty farm (Farm C), and (having reached the breeding age) they were inseminated here after a negative serological test (ELISA). At the same time, Farm A was depopulated, cleaned and disinfected. All pregnant gilts were transported from Farm C to Farm A after being tested negative with ELISA, where follow-up was performed after farrowing by two serological tests with an interval of six months. Based on the subsequent negative test results, the competent authority declared the herd PRRSV free. Conclusions:The farm presented in this study was the first in the course of the National PRRS Eradication Programme to eradicate PRRSV successfully by vaccinating the sows with an inactivated vaccine and performing segregated rearing of the offspring. Production was almost continuous during the whole process of the population replacement. Testing for monitoring purposes was also cheaper and simpler because of the use of an inactivated vaccine.

scholarly journals The Light and Shadow of Rapid Serological Tests for SARS-CoV-2 Infection: Results from a Study in a Large Emergency Department

2020 ◽  
Vol 17 (18) ◽  
pp. 6493
Author(s):  
Daniela Loconsole ◽  
Francesca Centrone ◽  
Caterina Morcavallo ◽  
Silvia Campanella ◽  
Anna Sallustio ◽  
...  
Keyword(s):  
Emergency Department ◽  
Real Time ◽  
Real Time Pcr ◽  
Respiratory Symptoms ◽  
Large Scale ◽  
Serological Test ◽  
Serological Tests ◽  
Serological Assay ◽  
Infected People ◽  
Screening Programs

A critical point in the management of the SARS-CoV-2 pandemic is the need to promptly identify the greatest number of infected people and to implement strict public health measures. In this study, the performance of a rapid serological test in a clinical setting was evaluated. Samples from 819 consecutive patients (with or without respiratory symptoms) admitted to a large Emergency Department were tested between 23 March and 21 April 2020. Patient samples were tested in a real-time PCR assay and a serological assay. In total, 148/819 patients (18.1%) tested positive for SARS-CoV-2 by real-time PCR. The serological test revealed that 70/819 patients (8.5%) had anti-SARS-CoV-2 IgM and/or IgG. The prevalence of anti-SARS-CoV-2 antibodies was significantly higher in patients with respiratory symptoms lasting for >7 days than in those with respiratory symptoms lasting for 0–7 days (p < 0.001). The serological assay had an overall sensitivity of 35.1% and an overall specificity of 97.3%. A high negative predictive value (96.7%) was reported for patients without respiratory symptoms. The results confirm that rapid serological assays alone are not sufficient for diagnosis of SARS-CoV-2 infection but can be incorporated into large-scale screening programs during periods in which the virus circulation is low.

scholarly journals Efficacy of a gE-deleted, bovine herpesvirus 1 (BoHV-1) inactivated vaccine

2009 ◽  
Vol 29 (7) ◽  
pp. 545-551 ◽  
Author(s):  
Alessandra D. Silva ◽  
Paulo A. Esteves ◽  
Diogenes Dezen ◽  
Anna P. Oliveira ◽  
Fernando R. Spilki ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Bovine Herpesvirus ◽  
Economic Losses ◽  
Inactivated Vaccine ◽  
Bovine Herpesvirus 1 ◽  
Glycoprotein E ◽  
Corticosteroid Administration ◽  
Herpesvirus Type ◽  
Bovine Herpesvirus Type 1

Bovine herpesvirus type 1 (BoHV-1) is recognized as a major cause of economic losses in cattle. Vaccination has been widely applied to minimize losses induced by BoHV-1 infections. We have previously reported the development of a differential BoHV-1 vaccine, based on a recombinant glycoprotein E (gE)-deleted virus (265gE-). In present paper the efficacy of such recombinant was evaluated as an inactivated vaccine. Five BoHV-1 seronegative calves were vaccinated intramuscularly on day 0 and boostered 30 days later with an inactivated, oil adjuvanted vaccine containing an antigenic mass equivalent to 10(7.0) fifty per cent cell culture infectious doses (CCID50) of 265gE-. Three calves were kept as non vaccinated controls. On day 60 post vaccination both vaccinated and controls were challenged with the virulent parental strain. No clinical signs or adverse effects were seen after or during vaccination. After challenge, 2/5 vaccinated calves showed mild clinical signs of infection, whereas all non vaccinated controls displayed intense rhinotracheitis and shed virus for longer and to higher titres than vaccinated calves. Serological responses were detected in all vaccinated animals after the second dose of vaccine, but not on control calves. Following corticosteroid administration in attempting to induce reactivation of the latent infection, no clinical signs were observed in vaccinated calves, whereas non vaccinated controls showed clinical signs of respiratory disease. In view of its immunogenicity and protective effect upon challenge with a virulent BoHV-1, the oil adjuvanted preparation with the inactivated 265gE- recombinant was shown to be suitable for use as a vaccine.

scholarly journals A European inter-laboratory trial to evaluate the performance of three serological methods for diagnosis of Mycoplasma bovis infection in cattle using latent class analysis

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Anna-Maria Andersson ◽  
Anna Aspán ◽  
Henk J. Wisselink ◽  
Bregtje Smid ◽  
Anne Ridley ◽  
...  
Keyword(s):  
Latent Class Analysis ◽  
Latent Class ◽  
Control Strategies ◽  
Clinical Signs ◽  
Laboratory Diagnosis ◽  
Economic Losses ◽  
Mycoplasma Bovis ◽  
Class Analysis ◽  
Serological Tests ◽  
Laboratory Trial

Abstract Background Mycoplasma bovis (M. bovis) is an emerging bovine pathogen, leading to significant economic losses in the livestock industry worldwide. Infection can result in a variety of clinical signs, such as arthritis, pneumonia, mastitis and keratoconjunctivitis, none of which are M. bovis-specific. Laboratory diagnosis is therefore important. Serological tests to detect M. bovis antibodies is considered an effective indicator of infection in a herd and often used as a herd test. Combined with clinical judgement, it can also be used to implement control strategies and/or to estimate the disease prevalence within a country. However, due to lack of harmonisation of approaches to testing, and serological tests used by different laboratories, comparisons of prevalence data between countries is often difficult. A network of researchers from six European countries designed and participated in an inter-laboratory trial, with the aim of evaluating the sensitivity (Se) and specificity (Sp) of two commercially available ELISA tests (ID Screen® ELISA (IDvet) and BIO K302 ELISA (BIO-X Diagnostics)) for diagnosis of M. bovis infection. Each laboratory received a blinded panel of bovine sera and tested independently, according to manufacturer’s instructions. Western blot analyses (WB) performed by one of the participating laboratories was used as a third diagnostic test in the statistical evaluation of Se and Sp values using latent class analysis. Results The Se of WB, the ID Screen® ELISA and the BIO K302 ELISA were determined to be 91.8, 93.5 and 49.1% respectively, and corresponding Sp of the three tests were 99.6, 98.6 and 89.6%, respectively. Conclusions The present study is, to our knowledge, the first to present an inter-laboratory comparison of the BIO K302 ELISA and the ID Screen® ELISA. Based on our results, the ID Screen® ELISA showed high consistency with WB and performed with higher precision and accuracy than the BIO K302 ELISA.

scholarly journals Development and Evaluation of a Trivalent Riemerella anatipestifer-Inactivated Vaccine

2013 ◽  
Vol 20 (5) ◽  
pp. 691-697 ◽  
Author(s):  
Haiwen Liu ◽  
Xiaolan Wang ◽  
Chan Ding ◽  
Xiangan Han ◽  
Anchun Cheng ◽  
...  
Keyword(s):  
Interleukin 2 ◽  
Animal Experiments ◽  
Clinical Signs ◽  
Economic Losses ◽  
Inactivated Vaccine ◽  
Mhc I ◽  
Content Type ◽  
Riemerella Anatipestifer ◽  
Serotype 1 ◽  
Antibody Titers

ABSTRACTRiemerella anatipestiferinfections cause major economic losses in the duck industry. In this study, a trivalent inactivated vaccine ofR. anatipestifer, including strains CH3 (serotype 1), NJ3 (serotype 2), and HXb2 (serotype 10), was developed. Animal experiments showed that the ducks that received two immunizations with the vaccine were 100% protected from challenge with strains from any of the three serotypes (1, 2, or 10). No death or clinical signs of diarrhea, tremors, or limb swelling were shown in the protected ducks. Also, noR. anatipestiferbacteria were isolated from the livers or brains of the protected ducks. Furthermore, no histopathological changes were observed in the liver, spleen, or brain samples from the protected ducks during histological examination. The ducks that received two immunizations with the vaccine generated high antibody titers of 1:3,200 to 1:6,400 against the three serotypes of strains. The vaccine significantly enhanced the production of gamma interferon (IFN-γ) and interleukin 2 (IL-2) after one immunization and enhanced the production of IL-4 and IL-10 after two immunizations. In addition, real-time PCR indicated that the expression of major histocompatibility complex I (MHC-I), as well as that of CD40 and CD154 molecules, was significantly increased after one immunization, and the expressions of both MHC-I and MHC-II molecules were increased after two immunizations. Our study indicates that the vaccine can induce both humoral and cellular immunities in ducks and offer effective protection againstR. anatipestiferinfection.

scholarly journals Detection of asymptomatic SARS-CoV-2 infections among healthcare workers: results from a large-scale screening program based on rapid serological testing.

2020 ◽  
Author(s):  
Francesca Maria Carozzi ◽  
Maria Grazia Cusi ◽  
Mauro Pistello ◽  
Luisa Galli ◽  
Alessandro Bartoloni ◽  
...  
Keyword(s):  
Large Scale ◽  
Screening Program ◽  
Serological Test ◽  
Contact Tracing ◽  
Winter Period ◽  
Serological Tests ◽  
Diagnostic Pcr ◽  
Predictive Values ◽  
The Individual

Abstract Objective: To evaluate the performance of two available rapid immunological tests for identification of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) antibodies and their subsequent application to a regional screening of health care workers (HCW) in Tuscany (Italy). Design: measures of accuracy and HCW serological surveillance Setting: 6 major health facilities in Tuscany, Italy. Participants: 17,098 HCW of the Tuscany Region. Measures of accuracy were estimated to assess sensitivity in 176 hospitalized Covid-19 clinical subjects at least 14 days after a diagnostic PCR-positive assay result. Specificity was assessed in 295 sera biobanked in the pre-Covid-19 era in winter or summer 2013-14 Main outcome measures: Sensitivity and specificity, and 95% confidence intervals, were measured using two serological tests, named T-1 and T-2. Positive and Negative predictive values were estimated at different levels of prevalence. HCW of the health centers were tested using the serological tests, with a follow- up nasopharyngeal PCR-test swab in positive tested cases. Results: Sensitivity was estimated as 99% (95%CI: 95%-100%) and 97% (95% CI: 90%-100%), whereas specificity was the 95% and 92%, for Test T-1 and T-2 respectively. In the historical samples IgM cross-reactions were detected in sera collected during the winter period, probably linked to other human coronaviruses. Out of the 17,098 tested, 3.1% have shown the presence of SARS-CoV-2 IgG antibodies, among them 6.8% were positive at PCR follow-up test on nasopharyngeal swabs. Conclusion Based on the low prevalence estimate observed in this survey, the use of serological test as a stand-alone test is not justified to assess the individual immunity status. Serological tests showed good performance and might be useful in an integrated surveillance, for identification of infected subjects and their contacts as required by the policy of contact tracing, with the aim to reduce the risk of dissemination, especially in health service facilities.

Non Invasive Screening for Fetal RHD-Genotype in All D-Negative Women Is Reliable and Cost-Effective.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 556-556
Author(s):  
C. Ellen Van der Schoot ◽  
Aicha Ait Soussan ◽  
Gouke J. Bonsel ◽  
Masja de Haas
Keyword(s):  
Cord Blood ◽  
Pregnant Women ◽  
Large Scale ◽  
Serological Test ◽  
Cost Effective ◽  
Maternal Plasma ◽  
Serological Tests ◽  
Non Invasive ◽  
Automated Assay ◽  
Cell Free Fetal Dna

Abstract About 40% of D-negative pregnant women receive antenatal anti-D despite a D-negative fetus. We have developed an automated assay for fetal genotyping using cell-free fetal DNA from maternal plasma to restrict antenatal prophylaxis to women carrying a D-positive fetus. This will save anti-D of which is worldwide shortage, and will prevent the unnecessary administration of a blood product. 1 ml of plasma is automatically presented (Tecan) to a DNA isolation-robot (Roche). The DNA-eluate is tested (after automatically pipetting) in triplicate in a real-time RHD exon7-PCR (ApplBios). Results Plasma from 2415 D-negative pregnant women, whose blood was sent in for 28–30th week antibody screening, has been tested. In 35 cases (1.44%) the women (10 weak D and 25 normal D-positive) were typed as D-positive by repeated serological tests, and excluded from the study. 1465 of the plasma’s (61.59%) were typed RhD positive and 915 RhD negative. Because the RHD exon7-PCR will give positive results in D-negative women carrying D-negative variant RHD genes such as RHDΨ, we determined the incidence of these genes in our studygroup. In all cases (n=39) with Ct values below 33.2 DNA was isolated from maternal leukocytes. Of the 19 cases with extremely low Ct values (&lt;32), 6 women carried an RHDΨ gene, 5 an RHD variant type VI, 3 weak D (type 1, 11 and 17) and 1 RHDdel. The 24 other women did not carry RHD genes. To compare the plasma PCR results with cord blood serology, all women and obstetric caregivers were sent questionnaires on cord blood serology. 55% responded (n=1257). For cases with discrepant results(n=21) or incompleted questionnaires(n=31) the laboratory which performed the cord blood typing was contacted. Finally, concordant results were obtained in 1249 of the cases. In 3 cases the genotype suggests D-positivity while serology is D-negative. In 5 cases no RHD-sequences were detected in plasma but cord blood was typed D-positive. For the discrepant cases it cannot be concluded yet, which assay gave the correct phenotype. Conclusion This is the first large scale automated study demonstrating the feasibility of screening D-negative women to restrict antenatal anti-D to women carrying D-positive fetuses. For the recognition of women at risk for immunization, the plasma-PCR test seems to be at least as reliable as the serological test. Furthermore, postnatal prophylaxis could have been given directly after delivery in all women with a positive PCR-result, saving cord blood serology tests and possibly increasing the effectiveness of postnatal prophylaxis. An economic evaluation demonstrated that this screening policy is cost effective in the Netherlands.

scholarly journals Copro-ELISA Prevalence of Fasciola hepatica in Cattle in Van, Turkey

2017 ◽  
Vol 45 (1) ◽  
pp. 7
Author(s):  
Aysegul Bostanci ◽  
Bekir Oğuz
Keyword(s):  
Fasciola Hepatica ◽  
Age Groups ◽  
Clinical Signs ◽  
Common Species ◽  
Elisa Test ◽  
Economic Losses ◽  
Sufficient Information ◽  
Serological Tests ◽  
Significant Difference ◽  
Fasciola Spp

Background: Fasciolosis is an important food borne zoonotic disease caused by Fasciola trematode parasites. There are two types of  Fasciola spp. namely F. hepatica and F. gigantica, widely distributed across the globe, affecting both human and animal hosts. In endemic regions, it is possible to base the diagnosis of fasciolosis on clinical signs and the season, however, it could be more useful to support these data with fecal examination and various hematologic and serological tests. The aim of this study was to determine the prevalence of fasciolosis in cattle in Van province by copro-ELISA technique.Materials, Methods & Results: Fecal samples from 140 cattle were technically collected and examined by sedimentationzinc sulphate flotation technique. Modified McMaster sedimentation technique was applied to the egg positive samples to determine the EPG values. Fasciola hepatica coproantigens in samples were investigated by ELISA. The coprological and antigen ELISA prevalence of fasciolosis were determined as 5.07% and 30.7%, respectively, which shows the significant difference between these methods in examining the rate of infection. The highest prevalence of fasciolosis infection was observed in 1-2 age groups (41.9%), and this prevalence was followed by 3-5 (31.2%) and ≤6 age group (5%). The differences between age groups were found significant (P < 0.05). The prevalence in female and male cattle was found as 30.1% and 35.3% This difference was not found statistically significant (P > 0.05). The highest prevalence was observed in Brown Swiss with the ratio of 40% and this was followed by 31% in Crossbreed and 22.6% in Rubia Gallega. The differences among breeds were not statistically significant (P > 0.05).Discussion: Fasciola hepatica is the most common species of liver flukes, and its pathogenicity leads to significant impact on the economy of the livestock industry. The economic losses consist of costs of anthelmintics, drenches, labor, liver condemnation at meat inspection; and losses in production due to mortality, reduction in meat, milk and reduction in growth rate, fertility and decreased feed intake, conversion and lower resistance to other disease.To diagnose fasciolosis, eggs can only be detected in feces after the tenth or twelfth week of infection once the parasites have matured. It is reported that routine microscopic methods used before this stage do not provide sufficient information about the current infection status. Therefore, serological tests have been introduced for the early diagnosis of the disease. Among these tests, the ELISA test based on detecting antigens has become the most commonly used test. It is known that the probability of ELISA to cross-react with parasites that carry similar immunogenic features and the similarities between antibodies generated in previous infections and new infections pose a challenge to making the definitive diagnosis. Therefore, it is reported that to predict the parasitic potential of the host and the success of treatment beforehand, the presence of Fasciola spp. antigens can be investigated in serum instead of antibodies. In conclusion, this study has established prevalence of fasciolosis in cattle raised in Van province using the copro-ELISA technique for the first time. It has been concluded that copro-ELISA could serve as a useful technique for herd diagnosis of fasciolosis in cattle in addition to fecal examinations particularly with respect to fasciolosis.

scholarly journals Intra Vitam Diagnosis of Neglected Gurltia paralysans Infections in Domestic Cats (Felis catus) by a Commercial Serology Test for Canine Angiostrongylosis and Insights into Clinical and Histopathological Findings—Four-Case Report

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 921
Author(s):  
Marcelo Gómez ◽  
Catalina García ◽  
Isabel Maldonado ◽  
Nikola Pantchev ◽  
Anja Taubert ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Diagnostic Method ◽  
Serological Test ◽  
Specific Antigen ◽  
Clinical Signs ◽  
Felis Catus ◽  
Serological Tests ◽  
Presumptive Diagnosis ◽  
Preliminary Study

Gurltia paralysans is a metastrongyloid nematode which belongs to the Angiostrongylidae family and presents tropism for veins of the subarachnoid space in vivo of domestic and wild felids causing a progressive and chronic clinical manifestation of paraparesis/paraplegia. The geographic distribution of G. paralysans includes rural and periurban areas of South America and was recently reported in Europe. To date, a definitive diagnosis of feline gurltiosis is still conducted by post-mortem examination of the spinal cord in affected animals. A presumptive diagnosis of feline gurltiosis can also be achieved based on data of compatible clinical signs and associated epidemiological risk factors. The aim of this preliminary study was to evaluate the commercial serological test Angio Detect TM® (IDEXX Laboratories) as a possible diagnostic method of feline gurltiosis in vivo. For the study, 10 domestic felines (Felis catus) which originated from a high endemic area of Southern Chile, were analyzed. All felines presented chronic paraparesis or severe paraplegia. Subsequently, commercial Angio Detect TM® serological tests for the detection of closely related Angiostrongylus vasorum in canids were performed according to manufacturer’s instructions. Conducted serological tests were positive in seven of ten felines showing paraplegia/paraparesis and presumably infected with G. paralysans, and four of them were additionally necropsied, and presented macroscopic findings compatible with feline gurltiosis. Furthermore, the presence of adult female and male G. paralysans specimens at the level of the subarachnoid vasculature in affected spinal cord segments were observed during necropsy. Histopathology demonstrated severe eosinophilic meningomyelitis, coagulopathies with thrombosis in G. paralysans-parasitized leptomeningeal veins. Results of this preliminary study suggest a cross-reaction between A. vasorum-specific antigens, which also parasitize blood vessels in vivo, and G. paralysans when using an Angio Detect TM® test, which suggests its helpful use as a new diagnostic method for feline gurltiosis in live domestic felines. Additional specific antigen research will be required in order to better understand the sensitivity and specificity of A. vasorum antigens used in this test and for existing cross-reactivity with G. paralysans-derived antigens for future a suitable intra vitam immunodiagnosis of neglected feline gurltiosis.

scholarly journals CLINICAL AND LABORATORY DIAGNOSES OF NEWCASTLE AND INFECTIOUS BURSAL DISEASES OF CHICKENS

2012 ◽  
Vol 8 (2) ◽  
pp. 131-140 ◽  
Author(s):  
AKM Rakibul Hasan ◽  
MH Ali ◽  
MP Siddique ◽  
MM Rahman ◽  
MA Islam
Keyword(s):  
Newcastle Disease ◽  
Serological Test ◽  
Clinical Signs ◽  
Virus Detection ◽  
Clinical History ◽  
Rapid Identification ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Serological Tests ◽  
Field Samples

A comparative study was conducted to compare the disease diagnostic parameters (clinical signs & postmortem findings, organism isolation, serological test and molecular method) used to diagnose the Newcastle disease (ND) and infectious bursal disease (IBD) during the period from March 2009 to February 2010 in the laboratory of the Department of Microbiology and Hygiene, Bangladesh Agricultural University (BAU), Mymensingh. A total of 187 sick and dead chickens (63 broilers and 124 layers) of different ages (1 week to >15 weeks) were collected from 12 selective poultry farms (4 broilers and 8 layers) of Mymensingh and Gazipur districts. Clinically, 7 (14.89%) of 63 affected broiler and 27 (30.68%) of 124 affected layer chickens were diagnosed as Newcastle disease (ND) whereas, 11 (23.4%) of 63 affected broiler and 6 (4.82%) of the 124 affected layer birds were diagnosed as IBD on the basis of clinical history, clinical signs and postmortem findings. Virus isolation from field samples was performed by inoculating each suspected sample into 10-day-old chicken embryos. Out of 34 ND suspected field samples, 26 (5 broilers and 21 layers) were positive for NDV isolation and 11 (8 broilers and 3 layers) of 17 IBD suspected field samples, were positive for IBDV isolation. For confirmatory diagnosis, virus detection was confirmed by serological tests (HI and AGID) and RT-PCR assay. Out of 34 clinically diagnosed ND field samples, 20 (5 broiler & 15 layer) were positive by RT-PCR assay and 15 (10 broiler & 5 layer) of 17 IBD suspected field samples, were positive by both AGIDT and RT-PCR assay. Of the 26 HA positive NDV suspected AF, 19 (4 broilers and 15 layers) were positive by both HI & RT-PCR assay whereas, 10 (7 broilers and 3 layers) of 11 IBDV isolation positive tissue suspension were positive by both AGIDT & RT-PCR assay in the laboratory. Therefore, it may be concluded that serological (HI & AGIDT) and molecular (RT-PCR) techniques which allow rapid identification of most of samples are the reliable, sensitive, specific and more accurate methods to detect the viruses for the confirmatory diagnosis of diseases.DOI = http://dx.doi.org/10.3329/bjvm.v8i2.11196 Bangl. J. Vet. Med. (2010). 8 (2) : 131-140 

scholarly journals Analytical Validation and Clinical Application of Rapid Serological Tests for SARS-CoV-2 Suitable for Large-Scale Screening

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 869
Author(s):  
Amedeo De Nicolò ◽  
Valeria Avataneo ◽  
Jessica Cusato ◽  
Alice Palermiti ◽  
Jacopo Mula ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Real Time Pcr ◽  
Large Scale ◽  
High Sensitivity ◽  
Analytical Validation ◽  
Pcr Assay ◽  
Serological Tests ◽  
Flow Test ◽  
Lateral Flow Test ◽  
Large Scale Screening

Recently, large-scale screening for COVID-19 has presented a major challenge, limiting timely countermeasures. Therefore, the application of suitable rapid serological tests could provide useful information, however, little evidence regarding their robustness is currently available. In this work, we evaluated and compared the analytical performance of a rapid lateral-flow test (LFA) and a fast semiquantitative fluorescent immunoassay (FIA) for anti-nucleocapsid (anti-NC) antibodies, with the reverse transcriptase real-time PCR assay as the reference. In 222 patients, LFA showed poor sensitivity (55.9%) within two weeks from PCR, while later testing was more reliable (sensitivity of 85.7% and specificity of 93.1%). Moreover, in a subset of 100 patients, FIA showed high sensitivity (89.1%) and specificity (94.1%) after two weeks from PCR. The coupled application for the screening of 183 patients showed satisfactory concordance (K = 0.858). In conclusion, rapid serological tests were largely not useful for early diagnosis, but they showed good performance in later stages of infection. These could be useful for back-tracing and/or to identify potentially immune subjects.

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