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The global pandemic coronavirus pneumonia (COVID-19), the disease infected by the new coronavirus (SARS-CoV-2), is extremely contagious. It is mainly spread among people through respiratory droplets, aerosols, direct or indirect contact, fecal-oral transmission, and cold chain transportation. Especially, patients who are in the incubation period or have no obvious symptoms already have the ability to infect others. SARS-C0V-2 is a positive-sense single-stranded RNA virus, with a single linear RNA segment. Each SARS-CoV-2 virion is 60-140 mm in diameter. Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as the spike (S), envelope(E), membrane (M), and nucleocapsid (N) proteins. To date, a variety of detection methods for the SARS-CoV-2 have been developed based on the virus structural basis and 'etiological characteristics, which would provide an effective guarantee for the diagnosis of COVID-19 patients and the control of the epidemic. In order to help for the early diagnosis and prevention of COVID-19, the pathogenic characteristics and recent progresses of detection base on nucleic acid, immunology and biosensors of the SARS-CoV-2 are reviewed in this paper.
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Currently, there is no availability of any proven specific treatment or prevention strategy to fight against COVID-19. Convalescent plasma (CP) therapy is expected to increase survival rates in COVID-19 as in the case of emerging viral infection (SARS-CoV and MERS-CoV). To collect all the studies relevant to CP therapy in critically ill or severe COVID-19 patients and summarize the findings. The systematic review was conducted according to the PRISMA consensus statement. A systematic search was performed in PubMed, Scopus, Web of Science, and Cochrane databases on April 25, 2020. A total of six studies (28 patients) relevant to CP therapy in severe or critical COVID-19 are considered for inclusion. Two authors extracted the data about study characteristics, demographics, symptoms, co-morbidities, clinical classification of COVID-19, drug therapies, oxygen therapy, laboratory results, chest CT, neutralizing antibody titer, SARS-CoV-2 RNA load, aal outcome. The review findings revealed that CP therapy increases lymphocyte count, reduced s serum inflammatory markers (CRP, IL-6, Procalcitonin) and liver enzyme levels (AST or ALT). There was a rise in serum neutralizing antibody titers in 10 of 14 patients after CP transfusion. In 4 of 14 patients, the titer levels remain unchanged after CP transfusion. All 28 cases (100%) achieved negative to the SARS-CoV-2 RNA after CP transfusion. The convalescent plasma transfusion can improve neutralizing antibody titers and reduces the viral load in severe/critical COVID-19 patients. The review recommends a well-controlled trial design is required to give a definite statement on the safety and efficacy of convalescent plasma therapy in severe/critical COVID-19.
ABSTRACT
The global pandemic coronavirus pneumonia (COVID-19), the disease infected by the new coronavirus (SARS-CoV-2), is extremely contagious. It is mainly spread among people through respiratory droplets, aerosols, direct or indirect contact, fecal-oral transmission, and cold chain transportation. Especially, patients who are in the incubation period or have no obvious symptoms already have the ability to infect others. SARS-C0V-2 is a positive-sense single-stranded RNA virus, with a single linear RNA segment. Each SARS-CoV-2 virion is 60-140 mm in diameter. Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as the spike (S), envelope(E), membrane (M), and nucleocapsid (N) proteins. To date, a variety of detection methods for the SARS-CoV-2 have been developed based on the virus structural basis and 'etiological characteristics, which would provide an effective guarantee for the diagnosis of COVID-19 patients and the control of the epidemic. In order to help for the early diagnosis and prevention of COVID-19, the pathogenic characteristics and recent progresses of detection base on nucleic acid, immunology and biosensors of the SARS-CoV-2 are reviewed in this paper.
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Objectives: Various reagents and equipment for testing SARS-CoV-2 infections have been developed, particularly rapid molecular tests based on polymerase chain reaction (PCR). Methods: We evaluated the analytical performance of four rapid molecular tests for SARS-CoV-2. We used 56 nasopharyngeal swabs from patients with confirmed SARS-CoV-2 infection;36 diagnosed as positive by the AmpdirectTM 2019-nCoV Detection Kit (Shimadzu assay) were considered as true-positive samples. Results: The sensitivity of CobasR Liat SARS-CoV-2 and Flu A/B (Cobas) was the highest among the four molecular test kits. The limit of detection was 1.49 x 10-2 copies/ micro L (95% confidence interval [CI]: 1.46x10-2-1.51 x 10-2 copies/ micro L) for Cobas;1.43 x 10-1 copies/ micro L (95% CI: 8.01x10-3-2.78 x 10-1 copies/ micro L) for XpertR Xpress SARS-CoV-2 test (Xpert);2.00 x 10-1 copies/ micro L (95% CI: 1.95x10-1-2.05 x 10-1 copies/ micro L) for FilmArray Respiratory Panel v2.1 (FilmArray);and 3.33 x 10 copies/ micro L (95% CI: 1.93 x 10-4.72x10 copies/ micro L) for Smart GeneR SARS-CoV-2 (Smart gene). Cobas also had a high sensitivity (100%) compared with Shimadzu assay. The sensitivities of Xpert, FilmArray, and Smart Gene were 97.2%, 97.2%, and 75.0%, respectively. The specificity of all tests was 100%. Conclusions: In conclusion, the four rapid SARS-CoV-2 molecular test kits have high specificity and sensitivity for detecting SARS-CoV-2. As they are easy to use, they could be a useful method for detecting SARS-CoV-2.
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Objective: Since the resumption of face-to-face education in October 2020, which was suspended due to the COVID-19 pandemic, coincides with the period when SARS-CoV-2 infection rates in young adults are on the rise. This study focuses on the 2019 corona virus outbreak in young adults, the largest link in the chain of transmission, which can be defined as silent contagious agents. It is aimed to provide epidemiological data by detecting virus disease (COVID-19) seropositivity with two different serological methods, and to evaluate the symptom-test performance relationship of asymptomatic/mild symptom/symptomatic cases. Methods: A cross-sectional study was conducted with students studying at Cappadocia University health programs between December 2020 and February 2021 and who will attend practice courses face-to-face. Participants were surveyed about their COVID-19 symptoms and disease histories based on SARS-CoV-2 exposure. For SARS-CoV-2 antibody detection, blood samples were taken from the participants and investigated with a single lateral flow immunoAssay (LFIA, Novatech, Turkey) cassette test. The samples with positive test result were then SARS-CoV-2 Anti-N IgM+IgG;SARS-CoV-2 Anti-S IgM+IgG;SARS-CoV-2 Anti-RBD IgG;It was re-evaluated using the electrochemiluminescence immunoassay (ECLIA) method with the anti-SARS-CoV-2 kit (Roche, Germany). Results: Of the 239 samples participating in the study, 50 (20.9%) samples that were positive for SARS-CoV2 IgM/ IgG according to the LFIA method were then studied again with the ECLIA method. According to the ECLIA result, 72% (36/50) of individuals against both nucleocapsid (N) and spike (S) antigens, and 70% (35) against RBD antigen were seropositive. Based on the ECLIA test results, 239 samples were studied and 50 samples were found to be IgM/IgG positive, with a sensitivity of 64% and a specificity of 93%. Contingence history was reported in 46% (n=23) of patients who were seropositive by both methods, while 30% (n=15) showed a COVID-19 clinic. Fifty four percent (n=27) of the participants reported that they did not have a PCR (polymerase chain reaction) test, but antibody response was observed in all of them. Only 28% (n=14) of seropositive patients reported positive PCR results, and 4% of them stated that they had a chronic disease. It will be important to continue to observe the serological status of young people, particularly in the context of new COVID-19 variants and in the low interest in mass vaccination campaigns targeting young people. Conclusion: It is thought that the performance of ECLIA with rapid casette test does not have a good degree of agreement and confirmation with different immunoassay tests would be more useful for epidemiological surveillance. Especially the new COVID-19 in the context of the variants and targeting youth due to the lack of interest in vaccination champaigns continue to monitor the serological status of young people it will be important.
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The availability of accurate and rapid diagnostic tools for COVID-19 is essential for tackling the ongoing pandemic. In this context, researchers in the UK have started testing a new Lateral Flow Device (LFD) based on proprietary Biotinylated anti SARS-CoV-2 S1 AffimerR technology that binds to the SARS-CoV2-S1 protein in anterior nasal swab samples, generating an ultrasensitive method for detection. This international study aimed to compare its performance against other available Antigen-detecting Rapid Diagnostic Tests (Ag-RDTs) in a real-world clinical setting. The study was completed under the frame of Project SENSORNAS RTC-20176501 in collaboration with MiRNAX Biosens Ltd. and Hospital Carlos III, it was documented internally and deposited in agreement to the ISO 13485 norm. All the data obtained are currently under submission and review from the Ethics Committee of Universidad Autonoma de Madrid.
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The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during wastewater treatment leads to concerns about whether this process may represent a focal point for the transmission of COVID-19. An epidemiological analysis, based on a COVID-19 IgG/IgM Rapid Test Cassette, performed on 134 wastewater workers from 59 wastewater treatment plants from the province of Granada (Spain) showed a seroprevalence of 8.95% in IgG for SARS-CoV-2, which is similar to the incidence rate found for the general population of the province (9.6%;95%CI = 7.2-12.8). These findings suggest that current safety measures are sufficient for the protection of workers against SARS-CoV-2.
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This study aimed to evaluate the performance of the PanbioTM Covid-19 Ag Rapid Test (Abbott) in a medical center in Ouagadougou. The PanbioTM COVID-19 Ag test was evaluated from January 26 to March 31, 2021 in symptomatic and asymptomatic patients in the medical Centre of Kossodo. A total of 268 individuals were tested by both SARS-CoV-2 RT-PCR, and antigen RDT. Of these 268 individuals, 52 were positive and 216 were negative for COVID-19 RT-PCR. The performance parameters of the test and its Kappa agreement with the RT-PCR were calculated according to the presence or absence of symptoms in the patients on one hand, and according to the time onset of symptoms on the other hand. The sensitivity of the PanbioTM COVID-19 Ag Rapid Test ranged from 29.63% (95% CI: 13.75 to 50.18) among COVID-19 asymptomatic patients, to 87.5% (95% CI: 52.91 to97.76) among symptomatic patients with symptom onset time of 1-5 days. Similarly, the PanbioTM COVID-19 Ag Rapid Test specificity was 97.3% (95% CI: 90.58 to 99.67) and 96.4% (95% CI: 91.81 to 98.82) in symptomatic and asymptomatic RT PCR negative patients. The PanbioTM COVID-19 Ag Rapid Test shows good performance in detecting COVID-19 cases in patients with a symptom onset time of less than seven (7) days. This performance is even better when the symptom onset is reduced to five (5) days. The results show that the antigen RDT is not suitable for COVID-19 detection among asymptomatic patients.
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Malaria is long known as a deadly vector borne infection, caused by five parasite species of the coccidian genus Plasmodia that are present in as many as 85 countries. Despite significant progresses have been achieved to control the infection by early diagnosis and artemisinin combination treatment, insecticide-treated nets and indoor residual spraying, malaria still represents a major public health issue in many endemic low-income countries. New diagnostic tools of higher sensitivity and specificity are now available for use in endemic countries to better guide diagnosis and treatment. In particular, highly sensitive rapid antigenic tests are now available and the loop-mediated isothermal amplification is a very promising and highly sensitive diagnostic tool. After 2015, decreasing morbidity and mortality trends have been stagnating because of limited funding, emergence of parasite and vector resistance to drugs and insecticides respectively and, recently, by the disrupting effect of COVID-19 pandemic. The incomplete knowledge of the complex immunity of malaria infection has slowed the development of an effective vaccine. However, in 2021, the RTS-S vaccine, however of suboptimal protective efficacy, has been made available for routine use in children above 5 months of age. Population movements has increased the chance of observing imported malaria in non-endemic areas, where malaria competent vectors may still exist.
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Feline coronavirus (FCoV) belongs among pathogens with common occurrence in the cats population in the whole world. FCoV is ubiquitous in environments with a higher concentration of cats, e.g. in shelters, multicat households and kennels. FCoV primarily attacks the digestive feline tract, replicates in its cells and is excreted in the feces to surroundings of permanently or transiently infected cats. The aim of the study was the detection of FCoV in the feces of newly admitted cats to the shelter by the qPCR method and by means of commercial rapid immunochromatographic (antigen) tests from three different producers. For each of the antigen tests, sensitivity and specifity were determined by comparison with the qPCR analysis result. Out of 70 examined fecal samples, viral RNA was by the qPCR analysis identified in 44 samples (62.9%). Neither the age nor the gender of cats played a significant role in the viral excretion. Found sensitivity of the antigen tests was at a low (< 35%;tests A and C) to a satisfactory level (> 50%, test B). The number of viral particles in the samples determined by the qPCR method did not correlate significantly with the result of the antigen tests. The results of this study suggest that the use of rapid antigen tests for routine screening of FCoV shedding in feline shelters is limited due to the high rate of false-negative results.
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Introduction: Scrub typhus is tropical zoonotic disease, commonly presented with multi organ dysfunction and high mortality rate in untreated patients. This study was done to identify clinical features commonly associated with scrub typhus during COVID pandemics, parameters associated with severe scrub typhus and mortality. Methods: This retrospective study was done in a tertiary care hospital with a total of 52 admitted scrub typhus positive patients in October 2020 to February 2022. Diagnosis was established by scrub IgM ELISA or Rapid antigen test. The clinical and laboratory data, duration of hospital stay and outcomes were collected. Common clinical and laboratory findings were of descriptive analysis. Factors associated with mortality were analysed using Chi-square test. Results: Fever was the most common presenting symptoms on admission (94.2%) followed by respiratory abnormalities (38.46%). Acute kidney injury was the most common organ failure on admission (67.3%), followed by acute liver injury (46.2%) and thrombocytopenia (32.7%). MODS was seen in 46.15%. Of the total, 30.8% were admitted in ICU. Mortality was seen in 7.7% of all patients. On Chi-square analysis, altered mental status and coagulopathy were associated with significant mortality with p value <0.05. Conclusion: Scrub typhus can manifest with potentially life-threatening complications such as acute kidney injury, acute liver injury, thrombocytopenia and MODS. The overall case-fatality rate was 7.7%, and presence of altered mental status and coagulopathy were associated with higher mortality. As per literature, COVID has changed few clinical profiles of scrub typhus compared to same center experience before.
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Like elsewhere around the globe, SARS-CoV-2 infection is spreading in rural Egypt. Due to high sensitivity and specificity, the gold standard of diagnostics is reverse transcription polymerase chain reaction PCR (RT-PCR). Rural areas without access to certified laboratories cannot take advantage of RT-PCR testing, and thus are dependent upon rapid antigen testing, a point-of-care test that requires less training and can produce results within 15 minutes. Rapid antigen testing can give an advantage to medical teams in rural settings by affording effective and early control of SARS-CoV-2 infection spread. We sought to assess the contribution of different COVID-19 testing procedures in rural Egypt. We conducted a prospective cohort study in a rural lab in Giza, Egypt. Approximately 223 individuals with potential SARS-CoV-2 infection were involved in the study during the pandemic peak in Giza, Egypt, from March 4 - May 30, 2021. Subjects were subjected to RT-PCR and rapid antigen testing, and the performance of each testing procedure was compared. Between March 4 - May 30, 2021, approximately 223 symptomatic individuals were included in this study. 190 patients (85.2%) were indicated as PCR positive for SARS-CoV-2, while 33 (14.8%) were PCR negative. In comparison, a rapid antigen test showed 178 out of 223 patients (79.8%) were indicated as positive, or 94% of the PCR-positive individuals. In Giza, a rural area of Egypt, RT-PCR had an optimal balance of sensitivity and specificity, however, the turnaround time was a limiting factor. Antigen testing, performed as a rapid point-of-care test, can play an effective role in rural outbreak control due to its ease of use and rapid results.
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In recent years, emerging molecular diagnostic tools based on clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) systems have opened up new opportunities for pathogen diagnosis. This article will focus on the potential capabilities of the existing and under-research CRISPR/Cas systems for rapid diagnosis of the coronavirus disease 2019 (COVID-19), and discuss their clinical applications and challenges.
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Coronavirus disease 2019 (COVID-19) was first reported in Wuhan, China, in December 2019 as an out-break of pneumonia of unknown origin. Previous studies have suggested the utility of chest computed tomography (CT) in the diagnosis of COVID-19 because of its high sensitivity (93%-97%), relatively simple procedure, and rapid test results. This study, performed in Japan early in the epidemic when COV1D-19 prevalence was low, evaluated the diagnostic accuracy of chest CT in a population present-ing with lung diseases having CT findings similar to those of COVID-19. We retrospectively included all consecutive patients (18 years old) presenting to the outpatient department of Keio University Hospital between March 1 and May 31, 2020, with fever and respiratory symptoms. We evaluated the perfor-mance of diagnostic CT for COVID-19 by using polymerase chain reaction (PCR) results as the refer-ence standard. We determined the numbers of false-positive (FP) results and assessed the clinical utility using decision curve analysis. Of the 175 patients, 22 were PCR-positive. CT had a sensitivity of 68% and a specificity of 57%. Patients with FP results on CT diagnosis were mainly diagnosed with diseases mimicking COVID-19, e.g., interstitial lung disease. Decision curve analysis indicated that the clinical utility of CT imaging was limited. The diagnostic performance of CT for COVID-19 was inadequate in an area with low COV ID-19 prevalence and a high prevalence of other lung diseases with chest CT findings similar to those of COVID-19. Considering this insufficient diagnostic performance, CT findings should be evaluated in the context of additional medical information to diagnose COVID-19.
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Introduction: A new type of coronavirus that has been discovered in humans since the outbreak occurred in Wuhan China, in December 2019 and caused a disease called Coronavirus Disease-2019 (COVID-19). Rapid testing of specific antibodies in a patient's blood is a good choice for quick and simple detection of COVID-19. However, RT-PCR remains the best standard for diagnosing COVID-19.
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This study aimed to evaluate the application and diagnostic efficacy of two different colloidal gold kits for the detection of 2019-nCoV immunoglobulin M antibody (anti-IgM) and immunoglobulin G antibody (anti-IgG) in Beijing, a low endemic area, and to guide the rational clinical application. The sera of 29 patients with confirmed novel coronavirus pneumonia (COVID-19) and 19 411 patients from the non-infected screening population were selected to evaluate the sensitivity, specificity and false-positive rate of the 2019-nCoV antibody test kits from Zhuhai Lizhu and Tangshan Innotek using colloidal gold immunochromatography. The sensitivity of Inotec 2019-nCoV was slightly higher than that of Lizhu 2019-nCoV, with a sensitivity of 58.62% and 55.17%, respectively;the specimen collection time of the all-negative group was significantly less than that of the antibody-positive group (P < 0.05);the false-positive rate of the two reagents in the low-prevalence area was 0.16%, and the false-positive rate of 2019-nCoV IgG was higher in Inotec than in Lizhu. The false positive rate for 2019-nCoV IgM was significantly higher than that for IgG for the same brand (Inotec ?2=14.756 09, P=0.000 0;Lizhu ?2=27.492 62, P=0.000). Conclusion The 2019-nCoV antibody test is rapid, simple and easy to perform, with high specificity, and can be used as a rapid screening indicator for new crowns;the specificity, correctness and negative predictive value of the two kits are good, and the application of the other kit for retesting when a positive result occurs can reduce the false positive rate of informing the clinic;the application and analysis of positive reports of new crown antibodies should be combined with the endemic area and clinical comprehensive judgment.
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Since the beginning of COVID-19 pandemic the Real Time sharing of genome sequences of circulating virus supported the diagnostics and surveillance of SARS-CoV-2 and its transmission dynamics. SARS-CoV-2 straightaway showed its tendency to mutate and adapt to the host, culminating in the emergence of variants; so it immediately became of crucial importance to be able to detect them quickly but also to be able to monitor in depth the changes on the whole genome to early identify the new possibly emerging variants. In this scenario, this manuscript aims to provide an overview of the existing methods for the identification of SARS-CoV-2 variants (from rapid method based on identification of one or more specific mutations to Whole Genome sequencing approach-WGS), taking into account limitations, advantages and applications of them in the field of diagnosis and surveillance of SARS-CoV-2.
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In order to build a specific, sensitive and rapid detection method for PAstV3 detection, the PAstVB gene sequences in Genbank were used and the conserved region in ORFlb was selected to design specific primers and TaqMan probe. Clinical stool samples were collected and preliminary detected by this newly established real-time RT-PCR method after reaction systems and conditions optimization. This detection method established in this study has a good linear relationship with the standard curve, with R2 value up to 0.9971. The sensitivity is 100 times higher than conventional PCR method, The variation co-efficient of in-batch and inter-batch repeatability test is less than 2.0%, indicating good repeatability. The detection results of Clinical samples showed that the positive rate of this method is higher than conventional PCR method. The establishment of this method provides a rapid detection means for PAstV3 laboratory diagnosis and epidemiological investigation.
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A new type of coronavirus (SARS-CoV-2) infection caused acute or fatal pneumonia. The virus is another coronavirus that is transmitted from animal to human and capable of transmitted from human to human, following the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS CoV). In order to control the epidemic as soon as possible, there is an urgent need, for rapid detection and confirmation of infected patients. In this study, according to the SARS CoV-2 whole genome published in GenBank as target gene, LAMP Desiner 2.0 software was used to screen efficient and highly specific combinatorial loop primers. The amplification characteristics of Bst 4.0 DNA polymerase relys RNA as template for DNA synthesis. Viral RNA-positive test results showed that 5 to 20 copies of virus nucleic acid could be detected. The inactivated virus was directly used as amplification template for clinical detection. The amplified nucleic acid molecules are combined with OG (Orange-Green) dye. Positive samples are green and negative samples are orange yellow.. The established SARS-CoV-2 one-step visual constant temperature rapid detection method realizes rapid detection of nucleic acids with high sensitivity. This study provides a new method for SARS-CoV-2 detection.