scholarly journals Comparison of diagnostic accuracy for eight SARS-CoV-2 serological assays

2021 ◽  
Vol 31 (1) ◽  
pp. 121-133
Author(s):  
Andrea Tešija Kuna ◽  
Marijana Miler ◽  
Mario Štefanović ◽  
Ivan Šamija ◽  
Josipa Periša ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Severe Disease ◽  
Comparison Study ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Serological Tests ◽  
Perfect Agreement ◽  
Significant Difference ◽  
Polymerase Chain

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests have been suggested as an additional diagnostic tool in highly suspected cases with a negative molecular test and determination of seroprevalence in population. We compared the diagnostic performance of eight commercial serological assays for IgA, IgM, and IgG antibodies to the SARS-CoV-2 virus. Materials and methods: The comparison study was performed on a total of 76 serum samples: 30 SARS-CoV-2 polymerase chain reaction (PCR)- negative and 46 SARS-CoV-2 PCR-positive patients with asymptomatic to severe disease and symptoms duration from 3-30 days. The study included: three rapid lateral flow immunochromatographic assays (LFIC), two enzyme-linked immunosorbent assays (ELISA), and three chemiluminescence immunoassays (CLIA). Results: Agreement between IgM assays were minimal to moderate (kappa 0.26 to 0.63) and for IgG moderate to excellent (kappa 0.72 to 0.92). Sensitivities improved with > 10 days of symptoms and were: 30% to 89% for IgM; 89% to 100% for IgG; 96% for IgA; 100% for IgA/IgM combination; 96% for total antibodies. Overall specificities were: 90% to 100% for IgM; 85% to 100% for IgG; 90% for IgA; 70% for IgA/IgM combination; 100% for total antibodies. Diagnostic accuracy for IgG ELISA and CIA assays were excellent (AUC ≥ 0.90), without significant difference. IgA showed significantly better diagnostic accuracy than IgM (P < 0.001). Conclusion: There is high variability between IgM assays independently of the assay format, while IgG assays showed moderate to perfect agreement. The appropriate time for testing is crucial for the proper immunity investigation.

scholarly journals Analytical evaluation of a new Microdisk™ technology-based multiplex HPV genotyping system – the QPLEX™ HPV genotyping kit

2019 ◽  
Vol 43 (4) ◽  
pp. 201-209
Author(s):  
Yong Kwan Lim ◽  
Oh Joo Kweon ◽  
Jee-Hye Choi ◽  
Seungman Park ◽  
Keumsim Jung ◽  
...  
Keyword(s):  
Analytical Performance ◽  
Comparison Study ◽  
Perfect Agreement ◽  
Hpv Genotyping ◽  
Precision Evaluation ◽  
Polymerase Chain ◽  
Interference Tests ◽  
Multiplex System

Abstract Background Recently, the QPLEX™ human papillomavirus (HPV) genotyping kit (QuantaMatrix, Seoul, Korea), a Microdisk™ technology-based multiplex system, was developed to detect 32 HPV genotypes. We evaluated the analytical performance of this kit by conducting a comparison study, precision evaluation and interference testing. Methods A total of 1594 cervical swab specimens were used to compare the QPLEX™ HPV genotyping kit with other commercially available kits (GeneFinder HPV Liquid Bead MicroArray Genotype polymerase chain reaction [PCR] kit, Infopia, Seoul, Korea; PANArray™ HPV Genotyping Chip, PANAGENE, Daejeon, Korea). For the determination of precision, we evaluated four types of precision profiles: repeatability, lot-to-lot variability, operator-to-operator variability and site-to-site variability. In addition, interference tests were performed with various interferents. Results The results of the QPLEX™ HPV genotyping kit showed almost perfect agreement with the other commercially available HPV genotyping assays. The combined precision was acceptable. In addition, there was no tested interferent that affected the results of the QPLEX™ HPV genotyping kit. Conclusions The QPLEX™ HPV genotyping kit showed acceptable analytical performance in our study. This assay could be a suitable option for HPV genotyping in routine and follow-up tests.

scholarly journals Seroprevalance of Toxoplasmosis in sheep and goat: Iraq/ Sulaimania

2011 ◽  
Vol 35 (1) ◽  
pp. 16-24
Author(s):  
Lazem H. Al-Taie
Keyword(s):  
Age Groups ◽  
Neural System ◽  
Farm Animals ◽  
Economic Losses ◽  
Age Group ◽  
Serum Samples ◽  
Serological Tests ◽  
Back Ground ◽  
Qualitative Determination

Back ground: Toxoplasmosis is an important zoonosis that causes economic losses in animal herds due to abortion and stillbirth as well as changes in the reproductive and neural system of susceptible animals . Objective: The aims of the present study is to determination the prevalence of T. gondii in farm animals ( sheep& goat)of both genders and different ages in Sulaimani province by using two serological tests (ELISA and LAT). Methods: Blood samples were collected from farm animals ,142 sheep and 46 goats , of different sexes and ages. Tow different serological tests ,ELISA and LAT for qualitative determination of T. gondii antibody titer in sheep and goats serum samples. Results: The prevalence rate in sheep was 73 (51.7 %) and 82 (57 %) , and 21 (54.6 %) and 25 (54.35 %) in goats ,by ELISA and LAT respectively. The prevalence of toxoplasmosis was highest in age group 7-9 (66.6%) in sheep in compares’ with other age groups. There was no significant differences between both spp.and tow test. Conclusion: Statistical results show no significant differences between both tests (ELISA &LAT) at (P ≥ 0.05).The prevalence of toxoplasmosis was increased proportionally with the age of animals, while gender has no effect on the prevalent rate .

scholarly journals Serological Investigations of Brucellosis in Cattle, Farmers and Veterinarians in the Kars District of Turkey

2008 ◽  
Vol 77 (1) ◽  
pp. 117-121 ◽  
Author(s):  
S. Otlu ◽  
M. Sahin ◽  
H. I. Atabay ◽  
A. Unver
Keyword(s):  
Control Measures ◽  
Serum Samples ◽  
Serological Tests ◽  
Significant Difference ◽  
High Prevalence ◽  
History Of ◽  
And Control

The prevalence of brucellosis was investigated in cattle, farmers and veterinarians in the Kars district of Turkey between 2004 - 2006. In order to achieve this, a total of 407 serum samples of cattle from 27 herds having history of abortions were examined for Brucella antibodies by RBPT and SAT. In addition, the sera collected from 246 farmers (130 males and 116 females) and 28 veterinarians in the same district were analysed serologically by RBPT, SAT and ELISA. Of the cattle sera analysed, 134 (32.92%) and 141 (34.64%) were determined as positive by RBPT and SAT, respectively. Thirty-two (13%), 35 (14.22%) and 44 (17.88%) of the farmers' sera were found positive for brucellosis by RBPT, SAT and ELISA, respectively. There was no significant difference between sexes for Brucella seropositivity. Of the 28 sera from veterinarians, 13 (46.42%) were positive by the three serological tests. The high prevalence of brucellosis both in cattle and humans suggests that brucellosis is common in this area. Preventive and control measures should be implemented and pursued more strictly to reduce and/or eradicate brucellosis from the area.

Determination of a T/G polymorphism at nucleotide 3206 of the apolipoprotein C III gene by amplification refractory mutation system

1994 ◽  
Vol 40 (12) ◽  
pp. 2235-2239 ◽  
Author(s):  
M Y Tsai ◽  
N Q Hanson ◽  
K R Copeland ◽  
I Beheshti ◽  
U Garg
Keyword(s):  
Epidemiological Studies ◽  
Amplification Refractory Mutation System ◽  
Chain Reaction ◽  
Apolipoprotein C ◽  
Significant Difference ◽  
Mutation System ◽  
Polymerase Chain ◽  
Exon 4 ◽  
And Control

Abstract We used the amplification refractory mutation system (ARMS)--a polymerase-chain-reaction-based method--to determine the 3206 T-to-G polymorphism on exon 4 of the apolipoprotein (apo) C III gene. Apo C III is an inhibitor of the enzyme lipoprotein lipase (EC 3.1.1.34). Previous studies have demonstrated that a polymorphism at nucleotide 3175 on exon 4 of this gene is associated with hypertriglyceridemia. We studied 45 hypertriglyceridemic and 46 age-matched controls for the 3206 T-to-G polymorphism. The results showed a significant difference in the distribution of the genotypes with respect to this allele between the hypertriglyceridemic and control individuals. We also determined the presence of the SacI site at nucleotide 3175 in these same individuals and found no significant difference in SacI genotypes between the two groups. This study reaffirms the usefulness of ARMS as a simple, reliable method for detecting mutations and polymorphisms in clinical and epidemiological studies.

Diagnostic value of anti-CD74 antibodies in early and late axial spondyloarthritis and its relationship to disease activity

Rheumatology ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 263-268 ◽  
Author(s):  
Marwa Mahmoud Abdelaziz ◽  
Rania M Gamal ◽  
Nadia M Ismail ◽  
Raghda A Lafy ◽  
Helal F Hetta
Keyword(s):  
Disease Activity ◽  
Axial Spondyloarthritis ◽  
Diagnostic Value ◽  
Inactive Disease ◽  
Control Group ◽  
Igg Antibodies ◽  
Control Groups ◽  
Significant Difference ◽  
Healthy Control

Abstract Objectives This study was designed to evaluate the role of anti-CD74 antibodies in diagnosis of axial spondyloarthritis (axSpA) and their relationship to disease duration and disease activity. Methods Fifty patients with axSpA, 15 patients with RA and 15 healthy subjects were included in the study. Clinical examination and laboratory tests were done. The ESR, CRP level and ASDAS were measured as markers of the disease activity. Quantitative determination of human CD74 IgG antibodies was done. Results The mean age of the patients was 38.22 (S.D.12.20) years. The level of CD74 autoantibodies was significantly higher in axSpA in comparison to control groups. Most patients with positive articular and extra-articular manifestations were positive for CD74 autoantibodies. In patients with inactive disease, 33.3% were positive for CD74 autoantibodies, as were 83% with active disease. High percentages of patients with early and late axSPA were CD74 autoantibody positive. The majority of patients with positive disease activity in early and late axSpA were CD74 autoantibody positive. CD74 autoantibodies had 80% sensitivity vs both control groups with 87% specificity vs the healthy control group and 80% vs the RA control group in the diagnosis of axSpA. Conclusions The frequency of positive anti-CD74 IgG antibodies was as high in patients with early axSpA as in those with late axSpA, with no significant differences. There was a significant difference in the frequency of positive anti-CD74 IgG antibodies between patients with positive and negative disease activity. Based on the sensitivity and specificity of anti-CD74 IgG, this is a promising diagnostic tool to support the clinical diagnosis of axSpA.

COVID-19 diagnostic laboratory strategies: modern technologies and development trends (review of literature)

2020 ◽  
Vol 65 (12) ◽  
pp. 757-766
Author(s):  
Boris Georgievich Andryukov ◽  
I. N. Lyapun
Keyword(s):  
Research Result ◽  
Simple Device ◽  
Epidemiological Surveillance ◽  
Serological Tests ◽  
Diagnostic Laboratory ◽  
Urgent Task ◽  
Polymerase Chain ◽  
Device Free ◽  
Modern Technologies

The COVID-19 pandemic, associated with the new coronavirus SARS-CoV-2, has caused a surge in incidence worldwide, as well as a severe crisis in global health and economy. Therefore, fast and accurate diagnosis of infection is key to timely treatment and elimination of the spread of the virus. Currently, the standard method for detecting coronavirus is reverse transcription polymerase chain reaction (RT-PCR). However, this method requires expensive equipment and trained personnel, which limits the conduct of mass testing and lengthens the time to obtain a research result. Serological tests for antibodies against SARS-CoV-2 and the determination of protective immunity in various populations are used to retrospectively identify patients with asymptomatic and mild forms of infection, monitor the course of infection in hospitalized patients, and also track contacts and epidemiological surveillance. The use of standard methods for diagnosing COVID-19 in conditions of mass morbidity, especially in conditions of insufficient resources and lack of appropriate infrastructure, is associated with a number of limitations. Therefore, the search and development of new, fast, inexpensive, simple, device-free and no less sensitive and specific tests is an urgent task. Therefore, the search and development of new, fast, inexpensive, simple, device-free and no less sensitive and specific tests is an urgent task. The review examines new laboratory technologies for diagnosing a new infection - loop isothermal amplification (LAMP) and immunochromatographic analysis (ICA), which can become a real alternative to the used molecular and enzyme immunoassay methods. The dynamic development of these methods in recent years expands the prospects for their use both for diagnosing COVID-19 and monitoring a pandemic.

scholarly journals Studies on the level of neutralizing antibodies produced by inactivated COVID-19 vaccines in the real world

2021 ◽  
Author(s):  
Haiying Zhang ◽  
Yuyuan Jia ◽  
Ying Ji ◽  
Xu Cong ◽  
Yan Liu ◽  
...  
Keyword(s):  
Real World ◽  
Linear Correlation ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Igg Antibodies ◽  
Serum Samples ◽  
The Real ◽  
Significant Difference ◽  
Positive Rate ◽  
High Linear Correlation

Background Although effective vaccines have been developed against COVID-19, the level of neutralizing antibodies (Nabs) induced after vaccination in the real world is still unknown. To evaluate the level and persistence of NAbs induced by two inactivated COVID-19 vaccines in China. Methods and findings Serum samples were collected from 1,335 people aged 18 and over who were vaccinated with COVID-19 inactivated vaccine in Peking University People's Hospital from January 19 to June 23, 2021, for detection of COVID-19 antibodies. The WHO standard of SARS-CoV-2 NAbs was detected. The coefficients of variation between the detection results and the true values of the NAbs detected by the WHO standard were all lower than the WHO international standard 3% after the dilution of the original and the dilution of the theoretical concentrations of 500 IU/mL, 250 IU/mL, 125 IU/mL, 72.5 IU/mL, 36.25 IU/mL and 18.125 IU/mL. On day 11-70, the positive rate of NAbs against COVID-19 was 82% to 100%; From day 71 to 332, the positive rate of NAbs decreased to 27%. The level of NAbs was significantly higher at 3-8 Weeks than at 0-3 Weeks. There was a high linear correlation between NAbs and IgG antibodies in 1335 vaccinated patients. NAbs levels were decreased in 31 of 38 people (81.6%) at two time points after the second dose of vaccine. There was no significant difference in age between the group with increased and decreased neutralizing antibody levels (x2 =-0.034, P>0.05). The positive rate of NAbs in the two-dose vaccine group (77.3%) was significantly higher than that in the one-dose group (18.1%), with statistical difference (x2=312.590, P<0.001). A total of 206 people who were 11-70 days after receiving the second dose were tested and divided into three groups: 18-40 years old, 41-60 years old and >60 years old. The positive rates of NAbs in three groups (18-40 years old, 41-60 years old and >60 years old) were 95.14%, 78.43% and 81.8%, respectively. The positive rate of NAbs was significantly higher in 18-40 years old than in 41-60 years old (x2=12.547, P <0.01). The titer of NAbs in 18-40 years old group was significantly higher than that in 41-60 years old group (t=-0.222, P <0.01). The positive rate of NAbs in male group (89.32%) was lower than in female (91.26%), but there was no significant difference (x2=0.222, P >0.05). Conclusions The positive rate of NAbs was the highest from 10 to 70 days after the second dose of vaccine, and the positive rate gradually decreased as time went by. There was a high linear correlation between COVID-19 NAbs and IgM/IgG antibodies in vaccinators, suggesting that in cases where NAbs cannot be detected, IgM/IgG antibodies can be detected instead. The level of NAbs produced after vaccination was affected by age, but not by gender. The highest levels of NAbs were produced between shots 21 to 56 days apart, suggesting that 21 to 56 days between shots is suitable for vaccination.

scholarly journals Evaluation of nine serological rapid tests for the detection of SARS-CoV-2

2020 ◽  
Vol 44 ◽  
pp. 1
Author(s):  
Marcela Mercado ◽  
Jeadran Malagón-Rojas ◽  
Gabriela Delgado ◽  
Vivian Vanesa Rubio ◽  
Lida Muñoz Galindo ◽  
...  
Keyword(s):  
Study Groups ◽  
Cross Sectional Study ◽  
Igg Antibodies ◽  
Sectional Study ◽  
Rt Pcr ◽  
Serum Samples ◽  
Serological Tests ◽  
Cross Sectional ◽  
Diagnostic Aid ◽  
Rapid Tests

Objective. To evaluate the operative capacity of nine serological rapid tests to detect the IgM/IgG antibodies response in serum from patients with SARS-CoV-2 in different clinical stages. Methods. A cross-sectional study of serological rapid tests was designed to compare the performance of the evaluated immunochromatographic tests for the diagnosis of SARS-CoV-2. A total of 293 samples was used, including negatives, asymptomatic, and symptomatic serum samples. Results. The sensitivity of the evaluated tests was low and moderate in the groups of asymptomatic serum samples and the group of serums coming from patients with less than 11 days since the onset of the symptoms. The specificity for the anti-SARS-CoV-2 antibodies tests ranged between 86.5%-99% for IgM and 86.5%-99.5% for IgG. The sensitivity and the likelihood ratio were different according to the study groups. The usefulness of these tests is restricted to symptomatic patients and their sensitivity is greater than 85% after 11 days from the appearance of symptoms. Conclusions. Serological tests are not an adequate strategy for the identification of asymptomatic and pre-symptomatic patients. Serological rapid tests for the detection of specific anti-SARS-CoV-2 antibodies can be used as a diagnostic aid, but diagnosis must be confirmed by RT-PCR. Rapid tests should be reserved for patients with symptoms lasting more than 11 days.

scholarly journals Seroprevalence and epidemiological characteristics of immunoglobulin M and G antibodies against SARS-CoV-2 in asymptomatic people in Wuhan, China

2020 ◽  
Author(s):  
Ruijie Ling ◽  
Yihan Yu ◽  
Jiayu He ◽  
Jixian Zhang ◽  
Sha Xu ◽  
...  
Keyword(s):  
General Hospital ◽  
Rural Areas ◽  
Immunoglobulin M ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serological Tests ◽  
Infected Population ◽  
Significant Difference ◽  
Epidemiological Characteristics ◽  
Back To Work

SummaryBackgroundThe seroprevalence of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be a more reliable approach to detect true infected population, particularly in asymptomatic persons. Few studies focus on the diagnosis of COVID-19 patients using serological tests. To detect and assess asymptomatic infections of COVID-19 among people in Wuhan, the epicenter of the COVID-19 pandemic in China, and provide evidence for planning adequate public health measures, we collected and analyzed the clinical data in the Wuhan General Hospital mandatory for 16- to 64-year-old asymptomatic people. This retrospective study estimated the seroprevalence of IgM and IgG and compared the epidemiological characteristics of asymptomatic SARS-CoV-2-infected population.MethodsDemographical and radiological data were collected from the Wuhan General Hospital between March 26 and April 28, 2020. Serological tests for IgM and IgG antibodies against SARS-CoV-2 were conducted with a colloidal gold method. Nucleic acid sequences of viruses were detected with RT-PCR. Statistical analyses were carried out using SPSS 20.0 software.FindingsBetween March 26 and April 28, 2020, 18,391 asymptomatic back-to-work participants were enrolled. Among them, 89 had positivity for IgM (0·48%, 95% confidence interval (CI): 0·38–0·58%); 620 cases had IgG positivity (3·37%, 95% CI: 3·11–3·64%), and 650 cases had either IgG positivity or IgM positivity (3·53%, 95% CI: 3·26–3·80%). After standardizing for the genders and ages in the population of Wuhan, the overall standardized seroprevalence of IgG was 3·33% (95% CI: 3·07–3·59%) and the standardized seroprevalence of IgG was 3·01% (95% CI: 2·69–3·33%) among males and 3·66% (95 % CI: 3·23–4·09%) among females. The standardized seroprevalence of IgG was higher in women than in men with a significant difference (χ2 = 2,060·3, p < 0·01). By a detection method adjustment, the seroprevalence of IgG was 1·57% (95% CI: 1·39–1·75%) in all medical records, of which males were 1·96% (95% CI: 1·64–2·28%), and females were 1·19% (95% CI: 0·99–1·39%). The assay-adjusted seroprevalence of IgG was higher in women than in men, and the difference was significant (χ2 = 5,871·0, p < 0·01). The differences were significant for the seroprevalence of IgG among people who went back to work in different categories of workplace (χ2 = 198·44, p < 0·01). The differences in seroprevalence for IgG positivity or IgM positivity among people who went back to work in different urban and rural areas was also significant (χ2 = 45·110, p < 0·01). Calculated as IgG and/or IgM antibody positivity, the number of new infections was reduced by 64·8% from March 26 to April 28, 2020. Based on the census population aged 16–64 years in Wuhan in 2017, we estimated that 172,340 (95% CI: 157,568–187,112) asymptomatic people aged 16–64 years were infected with SARS-CoV-2 in Wuhan between March 25 and April 28, 2020. This estimate was 3·4-times higher than the officially reported 50,333 infections on April 28.InterpretationThe seropositivity rate in Wuhan indicated that RT-PCR-confirmed patients only represented a small part of the total number of cases. Seropositivity progressively decreased in the Wuhan population from March 26 to April 28, 2020, comparable to Japan and Denmark, but well below the level reported in New York, Iran, Italy, and Germany. The prevalence of asymptomatic infection was higher in women than in men among people who went back to work in Wuhan. The low seroprevalence suggests that most of the population remains susceptible to COVID-19.FundingThe Emergency Management Project of the National Natural Science Foundation of China (81842035) and Advisory Research Project of the Chinese Academy of Engineering in 2019 (2019-XZ-70).

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