scholarly journals Salivary testing of COVID-19: evaluation of serological testing following positive salivary results

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lisa Caulley ◽  
Julie Shaw ◽  
Martin Corsten ◽  
Nadia Hua ◽  
Jonathan B. Angel ◽  
...  

Abstract Background Salivary detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proposed as an alternative to nasopharyngeal or oropharyngeal swab testing. Our group previously published a study demonstrating that both testing methods identified SARS-CoV-2 using polymerase chain reaction (PCR)-based detection methodology. We therefore conducted a follow-up study using antibody testing to evaluate the accuracy of saliva versus swabs for COVID-19 detection and the durability of antibody response. Methods Venous blood samples were collected from consenting participants and the presence of serum antibodies for SARS-CoV-2 was evaluated on a large, automated immunoassay platform by the Roche anti-SARS-CoV-2 qualitative assay (Roche Diagnostics, Laval Quebec). Individuals with a serum antibody cut-off index (COI) ≥ 1.0 were considered positive. Results In asymptomatic and mildly symptomatic patients with a previously positive standard swab and/or saliva SARS-CoV-2 PCR-test, 42 demonstrated antibodies with 13 patients positive by swab alone, and 8 patients positive by saliva alone. Conclusions Despite their status as ‘current standard’ for COVID-19 testing, these findings highlight limitations of PCR-based tests.

Author(s):  
Gopal Lama ◽  
Lilee Shrestha ◽  
Nabin Karmacharya ◽  
Rekha Manandhar ◽  
Runa Jha

Background: Coronavirus Disease 2019 (covid-19) is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). People who are infected with SARS-CoV-2 or are vaccinated with covid-19 vaccines are supposed to develop immunoglobulins and these immune responses in human body will determine the efficacy of the vaccines as well as help to discover new therapeutic options. Methods: A cross-sectional study conducted between April to June, 2021, assessing serum antibody titer from participants who had taken the first dose of covishieldTM vaccine (naïve as well as prior covid-19 infected individuals). Antibody testing was carried out with Roche Elecsys Anti-SARS-CoV-2 S electrochemiluminescence immunoassay on Roche Cobas e 601 module. Twenty-eight of these participants had follow up repeat antibody test after second dose of vaccine. Results: A total of 122 participants with the first dose of CovishieldTM vaccine were all tested seropositive, antibody titer ranging from minimum of 2.95 U/mL to maximum 2500 U/mL. Average antibody titer was 308.9 U/mL for naive cohort and 1604 U/mL for prior covid-19 infection. In twenty-eight participants who had antibody titer measured after 1 month of second dose, average titer was 1459.7 U/mL for naïve cohort and 1803.4 U/mL for prior covid-19 infected individuals, which was statistically significant compared to antibody response after the first dose. Conclusions: Antibody responses against SARS-CoV-2 following immunization was 100%, with significant development after second dose in naïve population while robust immune response was present after first dose in prior SARS-CoV-2 infected individuals.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Takahiro Matsuo ◽  
Akira Saito ◽  
Fujimi Kawai ◽  
Kazuhiro Ishikawa ◽  
Ryo Hasegawa ◽  
...  

Abstract Background Entamoeba histolytica (E. histolytica) is rarely identified as a cause of amebic pericarditis. We report a case of amebic pericarditis complicated by cardiac tamponade, in which the diagnosis was missed initially and was made retrospectively by polymerase chain reaction (PCR) testing of a stored sample of pericardial fluid. Furthermore, we performed a systematic review of the literature on amebic pericarditis. Case presentation A 71-year-old Japanese man who had a history of sexual intercourse with several commercial sex workers 4 months previously, presented to our hospital with left chest pain and cough. He was admitted on suspicion of pericarditis. On hospital day 7, he developed cardiac tamponade requiring urgent pericardiocentesis. The patient’s symptoms temporarily improved, but 1 month later, he returned with fever and abdominal pain, and multiple liver lesions were found in the right lobe. Polymerase chain reaction of the aspiration fluid of the liver lesion and pericardial and pleural fluid stored from the previous hospitalization were all positive for E. histolytica. Together with the positive serum antibody for E. histolytica, a diagnosis of amebic pericarditis was made. Notably, the diagnosis was missed initially and was made retrospectively by performing PCR testing. The patient improved with metronidazole 750 mg thrice daily for 14 days, followed by paromomycin 500 mg thrice daily for 10 days. Conclusions This case suggests that, although only 122 cases of amebic pericarditis have been reported, clinicians should be aware of E. histolytica as a potential causative pathogen. The polymerase chain reaction method was used to detect E. histolytica in the pericardial effusion and was found to be useful for the diagnosis of amebic pericarditis in addition to the positive results for the serum antibody testing for E. histolytica. Because of the high mortality associated with delayed treatment, prompt diagnosis should be made.


2021 ◽  
Author(s):  
Hari Ram Choudhary ◽  
Debaprasad Parai ◽  
Girish Chandra Dash ◽  
Annalisha Peter ◽  
Subrat Kumar Sahoo ◽  
...  

Abstract Objectives: Coronavirus disease-19 (COVID-19) pandemic became the greatest public health challenge globally. Study of dynamicity and durability of naturally developed antibodies against SARS-CoV-2 are of great importance from an epidemiological viewpoint.Methods: In this observational cohort study, we have followed up the 76 individuals who tested positive for SARS-CoV-2 infection by real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) for 16 weeks (post enrollment) to record the periodic changes in titre, concentration, clinical growth and persistence of naturally developed SARS-CoV-2 antibodies. We collected serum samples from these individuals for 16 weeks with a frequency of weekly and fortnightly during each follow-up and tested them in two CLIA-based platforms (Abbott Architect i1000SR and Roche Cobas e411) for testing SARS-CoV-2 antibodies both qualitatively and quantitatively.Results: We recorded the antibody magnitude of these individuals 10 times between September 2020 and February 2021. We found a waning of antibodies against nucleocapsid antigen protein but not a complete disappearance by the end of 16 weeks. Out of 76 cases, 30 cases (39.47%) became seronegative in qualitative assay, although all the sera samples (100%) remained positive when tested in quantitative assay.Conclusion: The lower persistence of anti-nucleocapsid SARS-CoV-2 antibody may not be the exact phenomenon as those cases were still seropositive against spike protein and help in neutralizing the virus.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249408
Author(s):  
Kuldeep Sharma ◽  
Pragya Aggarwala ◽  
Deepa Gandhi ◽  
Anuniti Mathias ◽  
Priyanka Singh ◽  
...  

Background An appropriate specimen is of paramount importance in Real Time reverse transcription-polymerase chain reaction (rRT-PCR) based diagnosis of novel coronavirus (nCoV) disease (COVID-19). Thus, it’s pertinent to evaluate various diversified clinical specimens’ diagnostic utility in both diagnosis and follow-up of COVID-19. Methods A total of 924 initial specimens from 130 COVID-19 symptomatic cases before initiation of treatment and 665 follow up specimens from 15 randomly selected cases comprising of equal number of nasopharyngeal swab (NPS), oropharyngeal swab (OPS), combined NPS and OPS (Combined swab), sputum, plasma, serum and urine were evaluated by rRT-PCR. Results Demographic analysis showed males (86) twice more affected by COVID-19 than females (44) (p = 0.00001). Combined swabs showed a positivity rate of 100% followed by NPS (91.5%), OPS (72.3%), sputum (63%), while nCoV was found undetected in urine, plasma and serum specimens. The lowest cycle threshold (Ct) values of targeted genes E, ORF1b and RdRP are 10.56, 10.14 and 12.26 respectively and their lowest average Ct values were found in combined swab which indicates high viral load in combined swab among all other specimen types. Analysis of 665 follow-up multi-varied specimens also showed combined swab as the last specimen among all specimen types to become negative, after an average 6.6 (range 4–10) days post-treatment, having lowest (15.48) and average (29.96) Ct values of ORF1b respectively indicating posterior nasopharyngeal tract as primary nCoV afflicted site with high viral load. Conclusion The combined swab may be recommended as a more appropriate specimen for both diagnosis and monitoring of COVID-19 treatment by rRT-PCR for assessing virus clearance to help physicians in taking evidence-based decision before discharging patients. Implementing combined swabs globally will definitely help in management and control of the pandemic, as it is the need of the hour.


2021 ◽  
Vol 8 ◽  
Author(s):  
Khitam Muhsen ◽  
Mitchell J. Schwaber ◽  
Jihad Bishara ◽  
Eias Kassem ◽  
Alaa Atamna ◽  
...  

Objectives: This study aims to examine the prevalence and risk factors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sero-positivity in health care workers (HCWs), a main risk group, and assess the sero-incidence of SARS-CoV-2 infection between the first and second waves of coronavirus disease 2019 (COVID-19) in Israel.Methods: A longitudinal study was conducted among 874 HCWs from nine hospitals. Demographics, health information, and blood samples were obtained at baseline (first wave—April–May 2020) and at follow-up (n = 373) (second wave—September–November 2020). Sero-positivity was determined based on the detection of total antibodies to the nucleocapsid antigen of SARS-CoV-2, using electro-chemiluminescence immunoassay (Elecsys® Anti-SARS-CoV-2, Roche Diagnostics, Rotkreuz, Switzerland).Results: The sero-prevalence of SARS-CoV-2 antibodies was 1.1% [95% confidence intervals (CI) 0.6–2.1] at baseline and 8.3% (95% CI 5.9–11.6) at follow-up. The sero-conversion of SARS-CoV-2 serum antibody was 6.9% (95% CI 4.7–9.9) during the study period. The increase in SARS-CoV-2 sero-prevalence paralleled the rise in PCR-confirmed SARS-CoV-2 infections among the HCWs across the country. The likelihood of SARS-CoV-2 sero-prevalence was higher in males vs. females [odds ratio (OR) 2.52 (95% CI 1.05–6.06)] and in nurses vs. physicians [OR 4.26 (95% CI 1.08–16.77)] and was associated with being quarantined due to exposure to COVID-19 patients [OR 3.54 (95% CI 1.58–7.89)] and having a positive PCR result [OR 109.5 (95% CI 23.88–502.12)].Conclusions: A significant increase in the risk of SARS-CoV-2 infection was found among HCWs between the first and second waves of COVID-19 in Israel. Nonetheless, the sero-prevalence of SARS-CoV-2 antibodies remains low, similar to the general population. Our findings reinforce the rigorous infection control policy, including quarantine, and utilization of personal protective equipment that should be continued together with COVID-19 immunization in HCWs and the general population.


2020 ◽  
Author(s):  
Agustin Lara-Esqueda ◽  
Sergio A Zaizar-Fregoso ◽  
Violeta M Madrigal-Perez ◽  
Mario Ramirez-Flores ◽  
Daniel A Montes-Galindo ◽  
...  

BACKGROUND Diabetes Mellitus is a worldwide health problem and the leading cause of premature death with increasing prevalence over time. Usually, along with it, Hypertension presents and acts as another risk factor that increases mortality risk. Both diseases impact the country's health while also producing an economic burden for society, causing billions of dollars to be invested in their management. OBJECTIVE The present study evaluated the quality of medical care for patients diagnosed with diabetes mellitus (DM), hypertension (HBP), and both pathologies (DM+HBP) within a public health system in Mexico, according to the official Mexican standard for each pathology. METHODS 45,498 patients were included from 2012 to 2015. All information was taken from the electronic medical records database, exported as anonymized data for research purposes. Each patient record was compared against the standard to test the quality of medical care. RESULTS Glycemia with hypertension goals reached 29.6% in DM+HBP, 48.6% in DM, and 53.2% in HBP. The goals of serum lipids were reached by 3% in DM+HBP, 5% in DM, and 0.2% in HBP. Glycemia, hypertension, and LDL cholesterol reached 0.04%. 15% of patients had an undiagnosed disease of diabetes or hypertension. Clinical follow-up examinations reached 20% for foot examination and clinical eye examination in the whole population. Specialty referral reached 1% in angiology or cardiology in the whole population. CONCLUSIONS Goals for glycemic and hypertension reached 50% in the overall population, while serum lipids, clinical follow-up examinations, and referral to a specialist were deficient. Patients who had both diseases had more consultations, better control for hypertension and lipids, but inferior glycemic control. Overall, quality care for DM and/or HBP has not been met according to the standards. While patients with DM and HBP do not have a current standard to evaluate their own needs.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 352
Author(s):  
Wei Wei ◽  
Valeria Trivellone ◽  
Christopher H. Dietrich ◽  
Yan Zhao ◽  
Kristi D. Bottner-Parker ◽  
...  

Phytoplasmas are obligate transkingdom bacterial parasites that infect a variety of plant species and replicate in phloem-feeding insects in the order Hemiptera, mainly leafhoppers (Cicadellidae). The insect capacity in acquisition, transmission, survival, and host range directly determines the epidemiology of phytoplasmas. However, due to the difficulty of insect sampling and the lack of follow-up transmission trials, the confirmed phytoplasma insect hosts are still limited compared with the identified plant hosts. Recently, quantitative polymerase chain reaction (qPCR)-based quick screening of 227 leafhoppers collected in natural habitats unveiled the presence of previously unknown phytoplasmas in six samples. In the present study, 76 leafhoppers, including the six prescreened positive samples, were further examined to identify and characterize the phytoplasma strains by semi-nested PCR. A total of ten phytoplasma strains were identified in leafhoppers from four countries including South Africa, Kyrgyzstan, Australia, and China. Based on virtual restriction fragment length polymorphism (RFLP) analysis, these ten phytoplasma strains were classified into four distinct ribosomal (16Sr) groups (16SrI, 16SrIII, 16SrXIV, and 16SrXV), representing five new subgroups (16SrI-AO, 16SrXIV-D, 16SrXIV-E, 16SrXIV-F, and 16SrXV-C). The results strongly suggest that the newly identified phytoplasma strains not only represent new genetic subgroup lineages, but also extend previously undiscovered geographical distributions. In addition, ten phytoplasma-harboring leafhoppers belonged to seven known leafhopper species, none of which were previously reported insect vectors of phytoplasmas. The findings from this study provide fresh insight into genetic diversity, geographical distribution, and insect host range of phytoplasmas. Further transmission trials and screening of new potential host plants and weed reservoirs in areas adjacent to collection sites of phytoplasma harboring leafhoppers will contribute to a better understanding of phytoplasma transmission and epidemiology.


2021 ◽  
pp. 101053952110110
Author(s):  
Salma Abbas ◽  
Aun Raza ◽  
Ayesha Iftikhar ◽  
Aamir Khan ◽  
Shahzaib Khan ◽  
...  

Health care personnel (HCP) are at high risk for coronavirus disease-2019 acquisition. Serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) indicate past infection. Our institution offered SARS-CoV-2 antibody testing to HCP. We surveyed HCP with positive test results to explore past exposure to SARS-CoV-2, details of symptoms during the preceding 6 months, and a history of SARS-CoV-2 polymerase chain reaction testing. A total of 2162 HCP underwent antibody testing. Eight hundred fifty-seven (39.6%) employees tested positive and, of these, 820 (95.7%) participated in the survey. When adjusted for age, males had higher odds of testing positive for SARS-CoV-2 antibodies compared with females (OR = 1.68; 95% CI = 1.37-2.05; P = .00) and clinical staff had higher odds of SARS-CoV-2 seropositivity compared with nonclinical staff (OR = 1.273; 95% CI = 1.06-1.53; P = .01). Implementation of effective infection control measures is essential to protect HCP from coronavirus disease-2019.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1383.2-1383
Author(s):  
S. G. Werner ◽  
H. E. Langer ◽  
P. Höhenrieder ◽  
R. Chatelain

Background:PCR (Polymerase Chain Reaction) is generally considered the gold standard for confirming the diagnosis in the early stages of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection. However, in our rheumatology outpatient clinic we observed a significant discrepancy between clinical evidence of COVID-19 and PCR results.Objectives:Aim of this retrospective study was to analyze the significance of PCR and serologic tests in the diagnosis of COVID-19 (Corona Virus Disease 2019) in a cohort of patients with rheumatic diseases.Methods:Between March 2020 and January 2021, 35 patients with a history of established COVID-19 or typical signs and symptoms were identified on the occasion of a routine rheumatology follow-up examination in our institution. Previous diagnostic work-up in external facilities (results of PCR or antibody testing, imaging) was documented. Antibody ELISA-tests (IgG, IgA, IgM, Euroimmun) were performed in patients reporting typical signs and symptoms of COVID-19 in the past.Results:PCR diagnostics had been performed in 15/35 patients (43%), in 13/35 (39%) at the onset of the first symptoms, in 2 subjects only 2 months later. PCR was positive in 7/13 (54%) of those tested early, but negative in the two patients tested later. In 29/35 patients (83%) SARS-CoV-2-ELISA tests were performed on the occasion of the routine rheumatologic examination (interval between first symptoms and testing on average 98 days, median86, range 4-283 days). In two of the initially negative individuals the second PCR was positive. ELISA tests were positive in all patients. SARS-CoV-2 IgM antibodies were positive in only two patients (however 55 and 71 days after disease onset), n=8/29 (28%) IgG only, n=9/29 (31%) IgG and IgA, n=12/29 (41%) IgA only. In these subjects, IgG antibodies did not develop even in the further course. Antibody titers were in part very high, but in part also very low (only just above the normal value), so even low titers were diagnostic obviously. In all patients with negative PCR, ELISA was positive and retrospectively led to confirmation of the diagnosis. Only in 13/35 patients (37%) diagnosis had been made with the onset of the first symptoms or in the course of clinically manifest disease and had led to appropriate quarantine measures and contact tracing by the health authorities. In contrast, in the majority of patients (63%), the diagnosis of COVID-19 infection was only made retrospectively on the occasion of a routine rheumatologic follow-up. However, 5 of these 22 patients (23%) had quarantined themselves during the symptomatic phase. Titer histories were available from 12 patients. The titer became negative in 7 patients, after a mean of 188 days (median 202, min 51, max 296 days), and remained positive in 5 individuals (mean 190 days, median 191, min 122, max 260 days). The change of the titer was independent of disease severity or antirheumatic therapy.Conclusion:The results suggest that the importance of PCR in the diagnosis of COVID-19 may be overestimated. Therefore, antibody testing for SARS-CoV-2 should be performed in cases of clinical suspicion and negative PCR. In antibody diagnostics, special features were observed compared to other viruses, in particular, in some patients only low antibody titers or the absence of seroconversion with lack of development of IgG antibodies. Normalization of antibody titers in some patients supports the recommendation to vaccinate even after expired COVID-19 disease.Disclosure of Interests:None declared


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 625.2-626
Author(s):  
H. Gerasimova ◽  
T. Popkova ◽  
I. Kirillova ◽  
M. Cherkasova ◽  
A. Martynova ◽  
...  

Background:N-terminal pro-brain natriuretic peptide (NT-proBNP) is a recognized predictor of congestive heart failure (CHF) and cardiovascular death. Rheumatoid arthritis (RA) patients (pts) were shown to have higher NT-proBNP concentrations than in general population, but it remains unclear, whether NT-proBNP levels are related to RA duration, activity or treatment.Objectives:To investigate the effect of interleukin 6 receptor inhibitor - tocilizumab (TCZ) and JAK inhibitor - tofacitinib (TOFA) on NT-proBNP levels in RA pts during a 12-month (m) follow-up period.Methods:The study enrolled 60pts (50women/10men) with the lack of efficacy/resistance and/or intolerance of basic anti-inflammatory drugs (DMARDs); median age was 55[42;61] years, median disease duration 55[29;120]m, with moderate to high activity (DAS28-5,1[4,6;6,1], serum positivity for rheumatoid factor (RF)(85%)/ anti-cyclic citrullinated peptide antibodies (ACCP)(80%). The study did not include RA pts with CHF and clinically overt cardiovascular disease (CVD). Twenty nine RA pts received TCZ(8mg/kg) every 4 weeks: 61% received TCZ in combination with methotrexate (MTX), 35% - with low-dose glucocorticoids (GCs). Thirty one RA pts were prescribed oral TOFA at 5 mg BID with dose escalation to 10 mg BID in 8 (26%)pts. TOFA was used in combination with MTX in 90% pts, with GCs – in 29% pts. Pts treated with TCZ and TOFA were comparable in terms of age, sex, body mass index. RA activity rates (DAS28, SDAI, ESR, CRP) were higher in pts on TCZ -therapy compared with pts treated with TOFA. Echocardiography data and NT-proBNP levels using electrochemiluminescence method Elecsys proBNP II (Roche Diagnostics, Switzerland) were obtained at baseline and after 12m.Results:Significant positive changes in major disease activity, clinical and laboratory parameters were found in RA pts after 12 m of TCZ infusion and TOFA intake: remission (DAS28<2,6) was achieved in 54% and 39% pts, low activity levels (DAS28<3,2) – in 46% and 51% pts, respectively.The NT-proBNP levels were significantly higher in RA pts than in the control group (median 69,1 (37,9;105,8) pg/mL vs 55,3 (36,6;67,3) pg/mL,p<0.05).Six pts (10%) (three in each pts group) had NT-proBNP levels over 125pg/ml, but were asymptomatic and had unremarkable echocardiography.There was a good correlation between NT-proBNP level at baseline with age (r=0,55,p<0,001), SDAI (r=0,5, h=0,01), ACCP (r=0,23,p=0,01).Decrease of median NT-proBNP levels was documented after 12m of TCZ therapy (81,5[43,0;102,0]vs41,6[25,4;64,2]pg/ml (p<0,01) and after 12m TOFA therapy (66,1[30,5;105,0]vs16,8 [5,0;81,0]pg/ml,p=0,001).After 12m of TCZ correlations of ΔNT-proBNP were established with ΔESR (R=0,43;p<0,05], ΔСRP (R=0,46;p<0,05], ΔEe left ventricle (LV) (r=0,88,p=0,03).In the group of pts treated with TOFA ΔNT-proBNP level significantly correlated with the percentage change in DAS 28 (r=0,41,p=0,038), there was no direct correlation with changes in the parameters of the LV diastolic function.Conclusion:TCZ and TOFA treatment for 12 m reduced NT-proBNP levels in RA pts without clinically manifest CVD and CHF. Falling NT-proBNP concentrations are associated with positive dynamics of RA activity (DAS 28) and inflammatory markers (CRP, ESR), therefore allowing to suggest that increased NT-proBNP levels should be considered as a component of disease activity. Correlation between ΔNT-proBNP and ΔEeLF may be indicative as possible impact of these biomarkers on the LV diastolic function’s development in RA pts.Disclosure of Interests:None declared


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