scholarly journals Lassa Virus Diagnostic Platforms: Limitations and Prospects

2020 ◽  
pp. 5-17
Author(s):  
Yahaya Hassan ◽  
Abdulhadi Sale Kumurya ◽  
Ibrahim Aminu ◽  
Sanusi Rahinatu Sharfadi ◽  
Abdullahi Alhassan Sharif
Keyword(s):  
Point Of Care ◽  
Lassa Fever ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lassa Virus ◽  
Rt Pcr ◽  
Isothermal Method ◽  
Polymerase Chain ◽  
Thermal Cycler ◽  
Low Sensitivity ◽  
And Control

Background: Lassa virus (LASV) is the cause of lassa fever (LF) belonging to the Arenaviridae family. Clinical diagnosis is often difficult because of symptoms commonality with other infectious diseases. Early and rapid diagnosis is critical for therapy initiation and LF transmission prevention and control. Aims: This review aims to highlight current diagnostic platforms and prospects of new emerging sensitive platforms. Methodology: Available published articles on LASV diagnostics with a focus on current methods: virus culture, enzyme-linked immunosorbent assay (ELISA), reverse transcriptase-polymerase chain reaction (RT – PCR) and rapid diagnostic tests (RDT) were reviewed based on their performances and limitations. Prospects of new diagnostic platforms: mobile health, microfluidic, clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas), Loop-mediated isothermal amplification (LAMP) for LASV diagnosis were also reviewed. Results: Low sensitivity of the ELISA platform during the window period of LASV infection was observed. Moreover, RT – PCR findings indicated limitation of expertise necessity, cost of thermal cycler, and dedicated facility. Molecular-based point-of-care (POC) diagnostic development should be prioritized to increase speed and sensitivity. Conclusion: The integration of POC device into molecular isothermal method against LASV scourge will be a success story in curving intermittent outbreaks in endemic areas and prompt clinical management.

scholarly journals Epidemiology and Control of Congo Fever in Sacrificial Animals of Pakistan

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Hafiz Muhammad Rizwan ◽  
Muhammad Sohail Sajid ◽  
Haider Abbas ◽  
Muhammad Fiaz Qamar ◽  
Qaiser Akram
Keyword(s):  
Tick Control ◽  
Enzyme Linked Immunosorbent Assay ◽  
Many Body ◽  
Rt Pcr ◽  
Body Tissues ◽  
Crimean Congo Haemorrhagic Fever ◽  
Polymerase Chain ◽  
And Control ◽  
Successful Prevention ◽  
Venereal Transmission

The cases and deaths due to Crimean-Congo haemorrhagic fever (CCHF) [49] virus commonly known as Congo virus (fatality rate 15%) have been reported throughout Pakistan from the last five years especially during religious occasion, Eid-ul-Azha. The annual increase in death rates due to CCHF demonstrate the importance of awareness of Congo fever at academia as well as public level. The symptoms of Congo fever which appear one to nine days after tick bite, include sudden high fever, muscle aches, abdominal pain, headache, dizziness, sore eyes, jaundice, mood swings, confusion, aggression, and sensitivity to light. The other signs include sore throat, joint pain, vomiting, diarrhea, hemorrhages, and bleeding from skin and large intestine. The Infection has been reported in many species of wild as well as domestic animals including hares, cattle, sheep, goats, dogs, mice and hedgehogs. At least 31 species of Hyalomma, Boophilus, Rhipicephalus, Dermacentor (Ixodidae: hard ticks) act as vector of CCHF in which transovarial, transstadial and venereal transmission occurs. The virus attacks the immune system of the host and influences the immune cells. The Congo fever virus can be isolated from blood, plasma and many body tissues (kidneys, liver, spleen, lungs, brain and bone marrow). Mice inoculation, enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR) can be used for detection of the infection. Furthermore, IgM and IgG antibodies against CCHFV can also be detected and quantified. Education of general public, tick control with acaricides, use of anti-CCHFV immunoglobulin, usage of approved repellents to prevent tick bites, wearing neutral-coloured garments, application of a permethrin spray to the clothing, avoiding tall grasses and shrubs, applying sunscreen, avoiding direct contact with the blood or tissues of animals are the factors for successful prevention of the infection.

scholarly journals Recent Advances in Novel Lateral Flow Technologies for Detection of COVID-19

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 295
Author(s):  
Wesley Wei-Wen Hsiao ◽  
Trong-Nghia Le ◽  
Dinh Minh Pham ◽  
Hui-Hsin Ko ◽  
Huan-Cheng Chang ◽  
...  
Keyword(s):  
Point Of Care ◽  
Lateral Flow ◽  
Enzyme Linked Immunosorbent Assay ◽  
Laboratory Diagnostics ◽  
Rt Pcr ◽  
Point Of Care Testing ◽  
Specific Point ◽  
Recent Advances ◽  
Highly Sensitive ◽  
Polymerase Chain

The development of reliable and robust diagnostic tests is one of the most efficient methods to limit the spread of coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, most laboratory diagnostics for COVID-19, such as enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR), are expensive, time-consuming, and require highly trained professional operators. On the other hand, the lateral flow immunoassay (LFIA) is a simpler, cheaper device that can be operated by unskilled personnel easily. Unfortunately, the current technique has some limitations, mainly inaccuracy in detection. This review article aims to highlight recent advances in novel lateral flow technologies for detecting SARS-CoV-2 as well as innovative approaches to achieve highly sensitive and specific point-of-care testing. Lastly, we discuss future perspectives on how smartphones and Artificial Intelligence (AI) can be integrated to revolutionize disease detection as well as disease control and surveillance.

scholarly journals Screening, Diagnostic and Prognostic Tests for COVID-19: A Comprehensive Review

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 561
Author(s):  
Mariana Ulinici ◽  
Serghei Covantev ◽  
James Wingfield-Digby ◽  
Apostolos Beloukas ◽  
Alexander G. Mathioudakis ◽  
...  
Keyword(s):  
Point Of Care ◽  
Standard Test ◽  
Current Evidence ◽  
Molecular Testing ◽  
Rt Pcr ◽  
Diagnostic Screening ◽  
Comprehensive Review ◽  
Prognostic Tests ◽  
Polymerase Chain ◽  
Antigen Testing

While molecular testing with real-time polymerase chain reaction (RT-PCR) remains the gold-standard test for COVID-19 diagnosis and screening, more rapid or affordable molecular and antigen testing options have been developed. More affordable, point-of-care antigen testing, despite being less sensitive compared to molecular assays, might be preferable for wider screening initiatives. Simple laboratory, imaging and clinical parameters could facilitate prognostication and triage. This comprehensive review summarises current evidence on the diagnostic, screening and prognostic tests for COVID-19.

scholarly journals Evaluation of Sandwich Enzyme-Linked Immunosorbent Assay and Reverse Transcription Polymerase Chain Reaction for the Diagnosis of Foot-and-Mouth Disease

Intervirology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Salman Khan ◽  
Syed Asad Ali Shah ◽  
Syed Muhammad Jamal
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Genome ◽  
Foot And Mouth Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Kappa Value ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Level Of Agreement

<b><i>Background:</i></b> Foot-and-mouth disease (FMD) is an infectious and highly contagious disease of cloven-hoofed domestic and wild animals, causing heavy economic losses to the livestock industry. Rapid and reliable diagnosis of the disease is essential for the implementation of effective control measures. This study compared sandwich enzyme-linked immunosorbent assay (S-ELISA) and conventional reverse transcription polymerase chain reaction (RT-PCR) for the diagnosis of FMD. <b><i>Methods:</i></b> A total of 60 epithelial samples from suspected cases of FMD were tested using both S-ELISA and RT-PCR assays. The level of agreement between the assays was assessed by calculating the Kappa value. <b><i>Results:</i></b> S-ELISA detected 38 (63%) samples positive for FMD virus (FMDV). Being predominant, serotype O was detected in 22 (57.9%) of the total samples tested positive, whereas 9 (23.7%) and 7 (18.4%) samples were found positive for serotypes A and Asia-1, respectively. RT-PCR detected viral genome in 51 (85%) of the samples using pan-FMDV primers set, 1F/1R. Thirty-six samples were found positive and 7 negative by both the tests. The level of agreement between the tests was assessed by calculating the Kappa value, which was found to be fair (Kappa value = 0.303 and 95% CI = 0.089; 0.517) and significant (<i>p</i> = 0.009). However, 2 samples, which were found positive on S-ELISA tested negative on RT-PCR. This may be attributed to the presence of nucleotide mismatch(es) in the primer-binding sites that may have resulted in failure of amplification of the viral genome. The serotype-specific RT-PCR assays not only confirmed serotyping results of S-ELISA but were also able to establish serotype in 9 S-ELISA-negative but pan-FMDV RT-PCR-positive samples. <b><i>Conclusions:</i></b> The RT-PCR assay contributes significantly to establishing a quick, sensitive, and definitive diagnosis of FMD in resource-constrained countries. Samples giving negative results in S-ELISA should be tested in RT-PCR for the disease detection and virus typing.

scholarly journals Monitoring Current-Season Spread of Potato virus Y in Potato Fields Using ELISA and Real-Time RT-PCR

Plant Disease ◽  
2013 ◽  
Vol 97 (5) ◽  
pp. 641-644 ◽  
Author(s):  
Manphool S. Fageria ◽  
Mathuresh Singh ◽  
Upeksha Nanayakkara ◽  
Yvan Pelletier ◽  
Xianzhou Nie ◽  
...  
Keyword(s):  
Real Time ◽  
Potato Virus ◽  
Potato Virus Y ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Current Season ◽  
Seed Market ◽  
Polymerase Chain ◽  
Time Of Harvest

The current-season spread of Potato virus Y (PVY) was investigated in New Brunswick, Canada, in 11 potato fields planted with six different cultivars in 2009 and 2010. In all, 100 plants selected from each field were monitored for current-season PVY infections using enzyme-linked immunosorbent assay (ELISA) and real-time reverse-transcription polymerase chain reaction (RT-PCR) assay. Average PVY incidence in fields increased from 0.6% in 2009 and 2% in 2010 in the leaves to 20.3% in 2009 and 21.9% in 2010 in the tubers at the time of harvest. In individual fields, PVY incidence in tubers reached as high as 37% in 2009 and 39% in 2010 at the time of harvest. Real-time RT-PCR assay detected more samples with PVY from leaves than did ELISA. A higher number of positive samples was also detected with real-time RT-PCR from growing tubers compared with the leaves collected from the same plant at the same sampling time. PVY incidence determined from the growing tubers showed a significant positive correlation with the PVY incidence of tubers after harvest. Preharvest testing provides another option to growers to either top-kill the crop immediately to secure the seed market when the PVY incidence is low or leave the tubers to develop further for table or processing purposes when incidence of PVY is high.

scholarly journals Development of Recombinant Nucleoprotein-Based Diagnostic Systems for Lassa Fever

2007 ◽  
Vol 14 (9) ◽  
pp. 1182-1189 ◽  
Author(s):  
Masayuki Saijo ◽  
Marie-Claude Georges-Courbot ◽  
Philippe Marianneau ◽  
Victor Romanowski ◽  
Shuetsu Fukushi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Hela Cells ◽  
Recombinant Baculovirus ◽  
Lassa Fever ◽  
Rabbit Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lassa Virus ◽  
Diagnostic Systems ◽  
Serum Samples ◽  
Capture Elisa

ABSTRACT Diagnostic systems for Lassa fever (LF), a viral hemorrhagic fever caused by Lassa virus (LASV), such as enzyme immunoassays for the detection of LASV antibodies and LASV antigens, were developed using the recombinant nucleoprotein (rNP) of LASV (LASV-rNP). The LASV-rNP was expressed in a recombinant baculovirus system. LASV-rNP was used as an antigen in the detection of LASV-antibodies and as an immunogen for the production of monoclonal antibodies. The LASV-rNP was also expressed in HeLa cells by transfection with the expression vector encoding cDNA of the LASV-NP gene. An immunoglobulin G enzyme-linked immunosorbent assay (ELISA) using LASV-rNP and an indirect immunofluorescence assay using LASV-rNP-expressing HeLa cells were confirmed to have high sensitivity and specificity in the detection of LASV-antibodies. A novel monoclonal antibody to LASV-rNP, monoclonal antibody 4A5, was established. A sandwich antigen capture (Ag-capture) ELISA using the monoclonal antibody and an anti-LASV-rNP rabbit serum as capture and detection antibodies, respectively, was then developed. Authentic LASV nucleoprotein in serum samples collected from hamsters experimentally infected with LASV was detected by the Ag-capture ELISA. The Ag-capture ELISA specifically detected LASV-rNP but not the rNPs of lymphocytic choriomeningitis virus or Junin virus. The sensitivity of the Ag-capture ELISA in detecting LASV antigens was comparable to that of reverse transcription-PCR in detecting LASV RNA. These LASV rNP-based diagnostics were confirmed to be useful in the diagnosis of LF even in institutes without a high containment laboratory, since the antigens can be prepared without manipulation of the infectious viruses.

scholarly journals Point-of-Care Diagnostics of COVID-19: From Current Work to Future Perspectives

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4289 ◽  
Author(s):  
Heba A. Hussein ◽  
Rabeay Y. A. Hassan ◽  
Marco Chino ◽  
Ferdinando Febbraio
Keyword(s):  
Point Of Care ◽  
Virus Detection ◽  
Diagnostic Tools ◽  
Sample Treatment ◽  
Rt Pcr ◽  
Point Of Care Diagnostics ◽  
Electrochemical Immunosensors ◽  
Global Concern ◽  
Polymerase Chain ◽  
Reliable Methods

Coronaviruses have received global concern since 2003, when an outbreak caused by SARS-CoV emerged in China. Later on, in 2012, the Middle-East respiratory syndrome spread in Saudi Arabia, caused by MERS-CoV. Currently, the global crisis is caused by the pandemic SARS-CoV-2, which belongs to the same lineage of SARS-CoV. In response to the urgent need of diagnostic tools, several lab-based and biosensing techniques have been proposed so far. Five main areas have been individuated and discussed in terms of their strengths and weaknesses. The cell-culture detection and the microneutralization tests are still considered highly reliable methods. The genetic screening, featuring the well-established Real-time polymerase chain reaction (RT-PCR), represents the gold standard for virus detection in nasopharyngeal swabs. On the other side, immunoassays were developed, either by screening/antigen recognition of IgM/IgG or by detecting the whole virus, in blood and sera. Next, proteomic mass-spectrometry (MS)-based methodologies have also been proposed for the analysis of swab samples. Finally, virus-biosensing devices were efficiently designed. Both electrochemical immunosensors and eye-based technologies have been described, showing detection times lower than 10 min after swab introduction. Alternative to swab-based techniques, lateral flow point-of-care immunoassays are already commercially available for the analysis of blood samples. Such biosensing devices hold the advantage of being portable for on-site testing in hospitals, airports, and hotspots, virtually without any sample treatment or complicated lab precautions.

scholarly journals Identification et caractérisation des isolats d'orbivirus des îles de la Réunion et de la Martinique

2009 ◽  
Vol 62 (2-4) ◽  
pp. 149
Author(s):  
D. Vitour ◽  
Corinne Sailleau ◽  
Emmanuel Breard ◽  
Stéphan Zientara
Keyword(s):  
Sequence Analysis ◽  
Clinical Symptoms ◽  
Enzyme Linked Immunosorbent Assay ◽  
La Réunion ◽  
Rt Pcr ◽  
Polymerase Chain ◽  
The One ◽  
Almost All ◽  
Haemorrhagic Disease

At the beginning of 2009, bluetongue (BT)-like clinical symptoms were reported in cattle on the French island of La Réunion (Indian Ocean). One hundred and twenty-three cows were blood tested for the presence of BT and/or epizootic haemorrhagic disease virus (EHDV) ribonucleic acid (RNA) by group specific reverse transcriptase polymerase chain reaction (RT-PCR). EHDV RNA was detected in 111 samples (90.2%), among which five were also positive for BTV RNA. Sequence analysis of EHDV segment 7 revealed that this circulating strain seemed to be similar to the one isolated in 2003 (99.8% nucleotide identity). The determination of the nucleotide sequence of segment 2 is under investigation. The vironeutralization test (VNT), serotype-specific RT-PCR, as well as sequence analysis identified the isolated BTV strain as serotype 2. These data showed that an EHDV outbreak occurred over the last winter in La Réunion, and it was concomitant to circulation of BTV. Epidemic or enzootic features of both these viruses are not yet known. Since this outbreak, molecular and serological tools specific to EHDV have been or are being developed. Three years ago, 30 healthy head of cattle moved from Metropolitan France to the French Martinique Island (Caribbean Basin) and were distributed in four different farms. Animals were sampled (blood and serum) every 10 days until day 30 and tested for BTV infection by the enzyme-linked immunosorbent assay (ELISA) or RT-PCR assays. Unexpectedly, almost all animals became BTV positive within 20 days. Whenever possible, virus isolation on eggs and baby hamster kidney (BHK) cell cultures were performed. Interestingly, seven BT strains belonging to seven distinct serotypes (BTV-2, 9, 10, 17, 18, 22, 24) were isolated. The coding sequence of segments 7, 8, 9 and 10 of these seven serotypes was obtained, as well as a portion of segment 2. The phylogenetic analysis revealed an unprecedented divergence of these strains with other known BTV sequences.

scholarly journals Serological and Molecular Detection of Hepatitis B virus among patients referred to Kurdistan Center for Hepatology and Gastroenterology in Sulaimani City/Kurdistan Region of Iraq

2020 ◽  
Vol 4 (2) ◽  
pp. 117
Author(s):  
Raz Sirwan Abdulla ◽  
Salih Ahmed Hama
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Dna ◽  
Molecular Techniques ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
B Virus ◽  
Polymerase Chain ◽  
Pcr Techniques ◽  
Positive Results

Hepatitis B virus infection is caused by the hepatitis B virus, a major global health problem. This infection can lead to chronic conditions, followed by cirrhosis and hepatocellular carcinoma (HCC). The current study was aimed to detect HBV using serological and molecular techniques. During 2019, 300 blood samples were collected from Kurdistan Center for Hepatology and Gastroenterology in Sulaimani city. Enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR) techniques were used for the detection of HBsAg and HBV DNA, respectively. Obtained results were revealed that 92 out of 300 tested patients (30.66%) seropositive for HBsAg. Among 92 seropositive patients, 53 were shown positive results for HBV DNA by RT-PCR. Dental clinic visiting and dialysis were among the important risk factors for HBV transmission. The vast majority of positive results were among males. Smokers showed relatively high rates of positive results. One-third of the referred patients who had liver complaints were positive for HBsAg. More than half of the seropositive patients showed RT-PCR positive results. It was concluded that the molecular method (RT-PCR) is more sensitive and gives a more accurate result than serology (ELISA). Therefore, it can be used as a diagnostic tool for HBV detection.

scholarly journals Point-of-Care Diagnostic Tools for Surveillance of SARS-CoV-2 Infections

2021 ◽  
Vol 9 ◽  
Author(s):  
Dhanasekaran Sakthivel ◽  
David Delgado-Diaz ◽  
Laura McArthur ◽  
William Hopper ◽  
Jack S. Richards ◽  
...  
Keyword(s):  
Large Scale ◽  
Clinical Symptoms ◽  
Point Of Care ◽  
Cost Effective ◽  
Nucleic Acid Amplification ◽  
Diagnostic Tools ◽  
Rt Pcr ◽  
Serological Tests ◽  
Polymerase Chain ◽  
Effective Public Health

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a recently emerged and highly contagious virus that causes coronavirus disease 2019 (COVID-19). As of August 24, 2021, there were more than 212 million confirmed COVID-19 cases and nearly 4.4 million deaths reported globally. Early diagnosis and isolation of infected individuals remains one of the most effective public health interventions to control SARS-CoV-2 spread and for effective clinical management of COVID-19 cases. Currently, SARS-CoV-2 infection is diagnosed presumptively based on clinical symptoms and confirmed by detecting the viral RNA in respiratory samples using reverse transcription polymerase chain reaction (RT-PCR). Standard RT-PCR protocols are time consuming, expensive, and technically demanding, which makes them a poor choice for large scale and point-of-care screening in resource-poor settings. Recently developed isothermal nucleic acid amplification tests (iNAAT), antigen and/or serological tests are cost-effective to scale COVID-19 testing at the point-of-care (PoC) and for surveillance activities. This review discusses the development of rapid PoC molecular tools for the detection and surveillance of SARS-CoV-2 infections.

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