SARS-CoV-2 antibody dynamics and transmission from community-wide serological testing in the Italian municipality of Vo’

AbstractIn February and March 2020, two mass swab testing campaigns were conducted in Vo’, Italy. In May 2020, we tested 86% of the Vo’ population with three immuno-assays detecting antibodies against the spike and nucleocapsid antigens, a neutralisation assay and Polymerase Chain Reaction (PCR). Subjects testing positive to PCR in February/March or a serological assay in May were tested again in November. Here we report on the results of the analysis of the May and November surveys. We estimate a seroprevalence of 3.5% (95% Credible Interval (CrI): 2.8–4.3%) in May. In November, 98.8% (95% Confidence Interval (CI): 93.7–100.0%) of sera which tested positive in May still reacted against at least one antigen; 18.6% (95% CI: 11.0–28.5%) showed an increase of antibody or neutralisation reactivity from May. Analysis of the serostatus of the members of 1,118 households indicates a 26.0% (95% CrI: 17.2–36.9%) Susceptible-Infectious Transmission Probability. Contact tracing had limited impact on epidemic suppression.

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Association between Platelet-Specific Collagen Receptor Glycoprotein 6 Gene Variants, Selected Biomarkers, and Recurrent Pregnancy Loss in Korean Women

Genes ◽

10.3390/genes11080862 ◽

2020 ◽

Vol 11 (8) ◽

pp. 862

Author(s):

Hui Jeong An ◽

Eun Hee Ahn ◽

Jung Oh Kim ◽

Chang Soo Ryu ◽

Han Sung Park ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Confidence Interval ◽

Odds Ratio ◽

Pregnancy Loss ◽

Adjusted Odds Ratio ◽

Recurrent Pregnancy Loss ◽

Korean Women ◽

Chain Reaction ◽

Genotype Frequencies ◽

Polymerase Chain

This paper investigates whether glycoprotein 6 (GP6) gene polymorphisms are a risk factor for recurrent pregnancy loss (RPL) in Korean women. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and real-time polymerase chain reaction amplification. We identified five polymorphisms in the GP6 gene: rs1654410 T>C, rs1671153 T>G, rs1654419 G>A, rs12610286 A>G, and rs1654431 G>A. GP6 rs1654410 CC was associated with decreased RPL risk (adjusted odds ratio = 0.292, 95% confidence interval = 0.105–0.815, p = 0.019), and recessive genotypes were also significantly associated with decreased RPL risk (adjusted odds ratio = 0.348, 95% confidence interval = 0.128−0.944, p = 0.038). GP6 rs1654419 GA was associated with decreased RPL risk (adjusted odds ratio = 0.607, 95% confidence interval = 0.375-0.982, p = 0.042), and dominant genotypes were significantly associated with decreased RPL risk (adjusted odds ratio = 0.563, 95% confidence interval = 0.358−0.885, p = 0.013). Altogether, the genotype frequencies of GP6 rs1654410 T>C and GP6 rs1654419 G>A were significantly different between RPL patients and control participants. Therefore, although GP6 polymorphisms may be useful as biomarkers of RPL, additional studies with heterogeneous cohorts are required to better understand the influence of GP6 and assess its performance as a biomarker.

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Current Avenues for COVID-19 Serology

Annals of the National Academy of Medical Sciences (India) ◽

10.1055/s-0040-1713709 ◽

2020 ◽

Vol 56 (02) ◽

pp. 087-090

Author(s):

Saumya Srivastava ◽

Vidhi Jain ◽

Vijaya Lakshmi Nag ◽

Sanjeev Misra ◽

Kuldeep Singh

Keyword(s):

Polymerase Chain Reaction ◽

Gold Standard ◽

Diagnostic Tests ◽

Immune Status ◽

Contact Tracing ◽

Great Promise ◽

Rt Pcr ◽

Chain Reaction ◽

Diagnostic Assays ◽

Polymerase Chain

AbstractDevelopment of rapid, reliable, and easy diagnostic tests with high-throughput is the need of the hour for laboratories combating the COVID-19 pandemic. While real-time polymerase chain reaction (RT-PCR) is the gold standard for diagnosing active infections, it is expensive and time-consuming. Serological diagnostic assays with a premise to aid rapid contact tracing, immune status determination, and identification of potential convalescent plasma donors hold great promise. Timely diagnosis, effective treatment, and future prevention are key to management of COVID-19.

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Difference in SARS-CoV-2 attack rate between children and adults may reflect bias

Clinical Infectious Diseases ◽

10.1093/cid/ciab183 ◽

2021 ◽

Cited By ~ 1

Author(s):

Zoë Hyde

Keyword(s):

Polymerase Chain Reaction ◽

Infectious Virus ◽

Data Interpretation ◽

Asymptomatic Infection ◽

Household Contact ◽

Serological Testing ◽

Chain Reaction ◽

Design Data ◽

High Prevalence ◽

Polymerase Chain

Abstract The epidemiology of coronavirus disease 2019 (COVID-19) in children has been challenging to establish, owing to the high prevalence of asymptomatic infection in this population. Lower secondary attack rates in children compared to adults have been observed in household contact studies, but there is evidence this may reflect lower testing in children and reduced exposure, rather than a genuine difference in biological susceptibility. Additionally, children may shed infectious virus for a shorter period than adults and their antibody response may be less broad, with implications for both polymerase chain reaction and serological testing. Improvements in study design, data collection, and data interpretation are required to better understand the epidemiology of COVID-19 in children.

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Evaluation method for asymmetric uncertainty of quantitative polymerase chain reaction measurements of deoxyribonucleic acids with low copy number

Scientific Reports ◽

10.1038/s41598-021-90959-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Unoh Ki ◽

Takeru Suzuki ◽

Satoshi Nakazawa ◽

Yuuki Yonekawa ◽

Kazuki Watanabe ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Confidence Interval ◽

Real Time ◽

Real Time Pcr ◽

Copy Number ◽

Limit Of Detection ◽

Quantitative Polymerase Chain Reaction ◽

Chain Reaction ◽

Low Copy Number ◽

Polymerase Chain

AbstractRecently, in food safety and various other fields, qualitative and quantitative gene analysis using real-time polymerase chain reaction (PCR) method has become increasingly popular. The limit of detection (LOD) and quantifiable range for these measurements depends on the range and precision of DNA calibrators’ concentrations. Low-copy-number nucleic acid reference materials with low uncertainty produced by an inkjet system have been developed to allow for precise measurements in a low-copy-number region. However, when using a calibrator with a low copy number near one, the copy number distribution is asymmetric. Consequently, the confidence intervals of estimated copy numbers can include negative values when conventional methods of uncertainty estimation are used. A negative confidence interval is irrelevant in the context of copy number, which is always positive value or zero. Here, we propose a method to evaluate the uncertainty of real-time PCR measurements with representative values and an asymmetric 95% confidence interval. Moreover, we use the proposed method for the actual calculation of uncertainty of real-time PCR measurement results for low-copy-number DNA samples and demonstrate that the proposed method can evaluate the precision of real-time PCR measurements more appropriately in a low-copy-number region.

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Determining the Most Accurate and Early Form for Detection of Lyme Disease

Maneto Undergraduate Research Journal ◽

10.15367/m:turj.v3i1.320 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Samantha Zaremba

Keyword(s):

Polymerase Chain Reaction ◽

Lyme Disease ◽

Diagnostic System ◽

Cost Effective ◽

Serological Testing ◽

Chain Reaction ◽

Early Form ◽

Chronic Lyme Disease ◽

Diagnostic Standards ◽

Polymerase Chain

Lyme disease is the most common vector-based disease with over 300,000 new cases each year. The current diagnostic system for those with Early Lyme disease is only about 40% accurate. Since the severity of symptoms and probability of recurrence significantly increases as time progresses, there is a need to find a new alternative diagnostic system for Early Lyme disease. Many solutions to this problem are considered within this document, most notably: polymerase chain reaction detection, metabolic biosignature testing, and OspC targeting serological testing. After further analysis, metabolic biosignature testing is considered the best alternative since it yields the highest diagnosis sensitivity with around 89% accuracy. Additionally, metabolic biosignature testing is both cost effective and widely applicable since it does not require the Erythema migran rash to be used. Once in place, Lyme disease will be able to be diagnosed quicker, thus reducing the number of cases of Chronic Lyme disease which significantly reduces personal quality of life and is often costly. Keywords: Early Lyme disease, Metabolic Biosignature, Serological testing, Borrelia burgdorferi, Diagnostic Standards, Polymerase Chain Reaction

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Diagnosis of Streptococcus pneumoniae Lower Respiratory Infection in Hospitalized Children by Culture, Polymerase Chain Reaction, Serological Testing, and Urinary Antigen Detection

Clinical Infectious Diseases ◽

10.1086/324358 ◽

2002 ◽

Vol 34 (1) ◽

pp. e1-e11 ◽

Cited By ~ 68

Author(s):

I. C. Michelow ◽

J. Lozano ◽

K. Olsen ◽

C. Goto ◽

N. K. Rollins ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Streptococcus Pneumoniae ◽

Respiratory Infection ◽

Hospitalized Children ◽

Lower Respiratory Infection ◽

Serological Testing ◽

Urinary Antigen ◽

Chain Reaction ◽

Polymerase Chain ◽

Urinary Antigen Detection

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Audit of treatment and contact-tracing rates in immediate (presumptive) versus delayed (polymerase chain reaction) diagnosis of chlamydial infection

International Journal of STD & AIDS ◽

10.1258/0956462054308378 ◽

2005 ◽

Vol 16 (7) ◽

pp. 502-503

Author(s):

I Fernando ◽

D J Clutterbuck

Keyword(s):

Polymerase Chain Reaction ◽

Success Rate ◽

Chlamydial Infection ◽

Contact Tracing ◽

Chain Reaction ◽

Medicine Clinic ◽

Gonococcal Urethritis ◽

Polymerase Chain

An audit of all cases of chlamydial infection diagnosed in men at the Edinburgh genitourinary (GU) medicine clinic over a six-month period from January 2003 is reported. In all, 189 men identified as requiring treatment for possible chlamydial infection on first attendance (because of contact with a partner with chlamydia or the diagnosis of non-gonococcal urethritis [NGU] on microscopy), who later proved chlamydia-positive by polymerase chain reaction (PCR), were compared with 83 men in whom infection was identified only on receipt of a PCR result. Treatment rates were 100% in the first group and 97.6% in the second group (χ2 0.046, P <0.05). In men presumptively diagnosed and treated, 88.6% of contacts identified were confirmed as traced, compared with 90% confirmed as traced in the group diagnosed by PCR alone. Our audit suggests that identifying men with chlamydial NGU by routine microscopy may carry a small but significant advantage in increasing treatment rates, but makes no difference to contact-tracing success rate.

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Are we prepared for the revolution in diagnostic technology?

Microbiology Australia ◽

10.1071/ma06055 ◽

2006 ◽

Vol 27 (2) ◽

pp. 55

Author(s):

Antony Della-Porta

Keyword(s):

Polymerase Chain Reaction ◽

Large Scale ◽

High Sensitivity ◽

Infectious Agents ◽

Serological Testing ◽

Chain Reaction ◽

The Past ◽

Dna And Rna ◽

Diagnostic Technology ◽

Polymerase Chain

The advances in diagnostic technology have been significant over the past 3 decades. The introduction of the enzyme linked immunoabsorbent assay (ELISA) revolutionised serological assays and enabled large scale automation of serological testing. Equally, the introduction of the polymerase chain reaction (PCR) enabled the amplification of DNA and RNA gene segments and the detection of infectious agents with high sensitivity and specificity.

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Development of a novel loop-mediated isothermal amplification assay for rapid detection of Mycobacterium leprae in clinical samples

Indian Journal of Dermatology Venereology and Leprology ◽

10.25259/ijdvl_248_19 ◽

2021 ◽

Vol 0 ◽

pp. 1-7

Author(s):

Shweta Joshi ◽

Vanila Sharma ◽

V. Ramesh ◽

Ruchi Singh ◽

Poonam Salotra

Keyword(s):

Polymerase Chain Reaction ◽

Confidence Interval ◽

Quantitative Polymerase Chain Reaction ◽

Mycobacterium Leprae ◽

Isothermal Amplification ◽

Chain Reaction ◽

Assay Sensitivity ◽

Loop Mediated Isothermal Amplification ◽

Amplification Assay ◽

Polymerase Chain

Background: Sensitive and definitive diagnostic tests are required for timely treatment of leprosy and to control its transmission. Aim: In the present study, we report the development of loop-mediated isothermal amplification assay using six primers targeting the RLEP gene sequence uniquely present in Mycobacterium leprae. Methods: Tissue punch samples (n = 50) and slit aspirates (n = 50) from confirmed cases of leprosy (M. leprae positive by quantitative polymerase chain reaction), reporting at the Department of Dermatology, Safdarjung Hospital, New Delhi, were analyzed using newly developed closed tube loop-mediated isothermal amplification assay. The sensitivity and specificity; positive predictive value, negative predictive value and accuracy were calculated using MedCalc statistical software. Results: The loop-mediated isothermal amplification assay specifically amplified M. leprae genomic DNA with an analytical sensitivity of 100 fg. About 47 Out of the 50 quantitative polymerase chain reactions confirmed M. leprae positive tissue samples, 47 were positive by loop-mediated isothermal amplification assay (sensitivity 94%; 95% confidence interval 83.5%–98.8%) while only 31/50 were positive by histopathology (sensitivity 62%; 95% confidence interval 47.2%–75.4%). Using slit aspirate samples of these 50 patients, 42 were positive by both quantitative polymerase chain reaction and loop-mediated isothermal amplification assay (sensitivity 84%; 95% confidence interval 70.9%–92.8%) while only 23/50 (sensitivity 46%; 95% confidence interval 31.8%–60.7%) were positive by microscopy. Limitations: In the present study, the leprosy patient cohort was not uniform, as it comprised of a lower number of paucibacillary cases (22%) compared to multibacillary (78%) cases. Conclusion: Loop-mediated isothermal amplification assay established here provides a rapid and accurate diagnostic test for leprosy in terms of sensitivity and specificity. The assay is simple to perform in comparison with other molecular techniques (polymerase chain reaction/quantitative polymerase chain reaction) and has potential for field applicability.

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