scholarly journals Correlation of Feline Coronavirus Shedding in Feces with Coronavirus Antibody Titer

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 598
Author(s):  
Sandra Felten ◽  
Ute Klein-Richers ◽  
Regina Hofmann-Lehmann ◽  
Michèle Bergmann ◽  
Stefan Unterer ◽  
...  
Keyword(s):  
Antibody Titer ◽  
Immunofluorescence Assay ◽  
Virus Load ◽  
Viral Loads ◽  
Three Samples ◽  
Antibody Titers ◽  
Polymerase Chain ◽  
Continuous Presence ◽  
Fecal Virus ◽  
Feline Coronavirus

Background: Feline coronavirus (FCoV) infection is ubiquitous in multi-cat households. Responsible for the continuous presence are cats that are chronically shedding a high load of FCoV. The aim of the study was to determine a possible correlation between FCoV antibody titer and frequency and load of fecal FCoV shedding in cats from catteries. Methods: Four fecal samples from each of 82 cats originating from 19 German catteries were examined for FCoV viral loads by quantitative reverse transcriptase polymerase chain reaction (RT-qPCR). Additionally, antibody titers were determined by an immunofluorescence assay. Results: Cats with antibodies were more likely to be FCoV shedders than non-shedders, and there was a weak positive correlation between antibody titer and mean fecal virus load (Spearman r = 0.2984; p = 0.0072). Antibody titers were significantly higher if cats shed FCoV more frequently throughout the study period (p = 0.0063). When analyzing only FCoV shedders, cats that were RT-qPCR-positive in all four samples had significantly higher antibody titers (p = 0.0014) and significantly higher mean fecal virus loads (p = 0.0475) than cats that were RT-qPCR-positive in only one, two, or three samples. Conclusions: The cats’ antibody titers correlate with the likelihood and frequency of FCoV shedding and fecal virus load. Chronic shedders have higher antibody titers and shed more virus. This knowledge is important for the management of FCoV infections in multi-cat environments, but the results indicate that antibody measurement cannot replace fecal RT-qPCR.

scholarly journals Measurement of antibody levels in patients with COVID-19 over time by immunofluorescence assay: a longitudinal observational study

2022 ◽  
Vol 50 (1) ◽  
pp. 030006052110692
Author(s):  
Betul Borku Uysal ◽  
Serap Yavuzer ◽  
Mehmet Sami Islamoglu ◽  
Mahir Cengiz
Keyword(s):  
Immunofluorescence Assay ◽  
Chain Reaction ◽  
Longitudinal Observational Study ◽  
Antibody Positivity ◽  
Antibody Titers ◽  
The Mean ◽  
Polymerase Chain ◽  
Antibody Levels ◽  
Serum Igg Levels ◽  
Over Time

Background During the coronavirus disease 2019 (COVID-19) pandemic, antibody screening is a critical tool to assess anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity. We examined variation in antibody titers associated with age and sex among patients with confirmed COVID-19. Methods Blood IgG levels were tested in 1081 patients with positive SARS-CoV-2 quantitative reverse transcription polymerase chain reaction (RT-qPCR) tests between 1 September and 31 December 2020. Patients who did not experience reinfection were identified. Serum IgG levels were measured by immunofluorescence assay. Antibody positivity and antibody titers were analyzed according to time since infection, sex, and age. Results The mean (standard deviation) age was 41.2 (14.2) years and 41.2% of patients were women. The lowest antibody positivity rate between the first and ninth month post-infection was detected in the sixth month. The lowest antibody titers among patients aged 20 to 80 years occurred in those aged 30 to 39 years. The IgG titer was positively correlated with age in years (r = 0.125) and decades (r = 0.126). Conclusions Six months after infection, anti-SARS-CoV-2 antibody titers increased. Anti-SARS-CoV-2 antibody titers also increased with age. Immunity and pathogenicity should be investigated in addition to antibody positivity rates and antibody titers.

scholarly journals A comparative study of techniques used for the diagnosis of effusive feline infectious peritonitis

2020 ◽  
Vol 89 (2) ◽  
pp. 100-110
Author(s):  
A. Hellemans ◽  
D. D. Acar ◽  
V. J. E. Stroobants ◽  
S. Theuns ◽  
L. M. B. Desmarets ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
High Sensitivity ◽  
Good Alternative ◽  
Chain Reaction ◽  
Reading Frame ◽  
Feline Infectious Peritonitis ◽  
Antibody Titers ◽  
Polymerase Chain ◽  
Low Sensitivity ◽  
Feline Coronavirus

Feline infectious peritonitis (FIP) is a fatal disease caused by feline infectious peritonitis virus (FIPV). At present, neither a licensed treatment nor an accurate ante-mortem diagnosis are available. In the present study, three available tests were evaluated for their diagnostic power on effusion samples. High feline coronavirus antibody titers, measured with an immunoperoxidase monolayer assay (IPMA), were correlated with FIP but its low specificity precluded a reliable diagnosis. The in-house 5’ reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) provided a much better specificity and high sensitivity. Given the low sensitivity of immunofluorescence staining (IF) of effusive cells, the RT-qPCR alone or in combination with IPMA represents a good alternative for IF. In the majority of the effusion samples from FIP positive animals, Sanger sequencing of the open reading frame encoding the spike protein (ORF S) revealed not only mutations that were previously associated with FIP (M1058L, S1060A, I1106T and D1108Y/E/G) but also two new, closely related mutations (T1112S/N).

scholarly journals Effect of cat litters on feline coronavirus infection of cell culture and cats

2019 ◽  
Vol 22 (4) ◽  
pp. 350-357 ◽  
Author(s):  
Diane Addie ◽  
Lene Houe ◽  
Kirsty Maitland ◽  
Giuseppe Passantino ◽  
Nicola Decaro
Keyword(s):  
Cell Culture ◽  
Virus Infection ◽  
Real Life ◽  
In Vitro Study ◽  
Oral Route ◽  
Virus Shedding ◽  
Virus Load ◽  
Fuller’S Earth ◽  
Feline Coronavirus

Objectives Feline infectious peritonitis (FIP) is caused by infection with feline coronavirus (FCoV). FCoV is incredibly contagious and transmission is via the faecal–oral route. FCoV infection, and therefore FIP, is most common in breeder and rescue catteries, where many cats are kept indoors, using litter trays. Whether it is possible to break the cycle of FCoV infection and reinfection using cat litters has never been investigated. The aim of the study was to examine the effect of cat litters on FCoV infectivity and virus load in multi-cat households, and transmission frequency. Methods Fifteen cat litters were mixed and incubated with FCoV, centrifuged and the supernatants tested in vitro for the ability to prevent virus infection of cell culture. To test applicability of in vitro results to real life, virus load was measured in two households in a double crossover study of four Fuller’s earth-based cat litters by testing rectal swabs using FCoV reverse transcriptase quantitative PCR. Results Four litters abrogated FCoV infection of cell culture, nine reduced it to a greater or lesser extent and two had no effect. One brand had different virus inhibitory properties depending on where it was manufactured. Fuller’s earth-based litters performed best, presumably by adsorbing virus. In the field study, there appeared to be less virus shedding on one Fuller’s earth-based cat litter. Conclusions and relevance The in vitro study successfully identified cat litters that inactivate FCoV; such litters exist so do not need to be developed. Fuller’s earth-based litters best prevented infection of cell culture, but did not completely abrogate FCoV transmission in two multi-cat households. A dust-free clumping Fuller’s earth litter appeared to fare best, but virus shedding also varied on the control litters, complicating interpretation. Sawdust-based cat litters are not useful in FCoV-endemic households because they track badly and have a poor effect on virus infection.

scholarly journals Estimating epidemiologic dynamics from cross-sectional viral load distributions

Science ◽  
2021 ◽  
pp. eabh0635
Author(s):  
James A. Hay ◽  
Lee Kennedy-Shaffer ◽  
Sanjat Kanjilal ◽  
Niall J. Lennon ◽  
Stacey B. Gabriel ◽  
...  
Keyword(s):  
Population Distribution ◽  
Quantitative Polymerase Chain Reaction ◽  
Cross Sectional ◽  
Outbreak Management ◽  
Viral Loads ◽  
Time Estimates ◽  
Load Distributions ◽  
Random Samples ◽  
Combining Data ◽  
Polymerase Chain

Estimating an epidemic’s trajectory is crucial for developing public health responses to infectious diseases, but case data used for such estimation are confounded by variable testing practices. We show that the population distribution of viral loads observed under random or symptom-based surveillance, in the form of cycle threshold (Ct) values obtained from reverse-transcription quantitative polymerase chain reaction testing, changes during an epidemic. Thus, Ct values from even limited numbers of random samples can provide improved estimates of an epidemic’s trajectory. Combining data from multiple such samples improves the precision and robustness of such estimation. We apply our methods to Ct values from surveillance conducted during the SARS-CoV-2 pandemic in a variety of settings and offer alternative approaches for real-time estimates of epidemic trajectories for outbreak management and response.

scholarly journals Performance of the Innova SARS-CoV-2 antigen rapid lateral flow test in the Liverpool asymptomatic testing pilot: population based cohort study

BMJ ◽  
2021 ◽  
pp. n1637 ◽  
Author(s):  
Marta García-Fiñana ◽  
David M Hughes ◽  
Christopher P Cheyne ◽  
Girvan Burnside ◽  
Mark Stockbridge ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Load ◽  
Predictive Value ◽  
High Viral Load ◽  
Test Results ◽  
Chain Reaction ◽  
Viral Loads ◽  
Flow Test ◽  
Polymerase Chain ◽  
Lateral Flow Test

Abstract Objective To assess the performance of the SARS-CoV-2 antigen rapid lateral flow test (LFT) versus polymerase chain reaction testing in the asymptomatic general population attending testing centres. Design Observational cohort study. Setting Community LFT pilot at covid-19 testing sites in Liverpool, UK. Participants 5869 asymptomatic adults (≥18 years) voluntarily attending one of 48 testing sites during 6-29 November 2020. Interventions Participants were tested using both an Innova LFT and a quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) test based on supervised self-administered swabbing at testing sites. Main outcome measures Sensitivity, specificity, and predictive values of LFT compared with RT-qPCR in an epidemic steady state of covid-19 among adults with no classic symptoms of the disease. Results Of 5869 test results, 22 (0.4%) LFT results and 343 (5.8%) RT-qPCR results were void (that is, when the control line fails to appear within 30 minutes). Excluding the void results, the LFT versus RT-qPCR showed a sensitivity of 40.0% (95% confidence interval 28.5% to 52.4%; 28/70), specificity of 99.9% (99.8% to 99.99%; 5431/5434), positive predictive value of 90.3% (74.2% to 98.0%; 28/31), and negative predictive value of 99.2% (99.0% to 99.4%; 5431/5473). When the void samples were assumed to be negative, a sensitivity was observed for LFT of 37.8% (26.8% to 49.9%; 28/74), specificity of 99.6% (99.4% to 99.8%; 5431/5452), positive predictive value of 84.8% (68.1% to 94.9%; 28/33), and negative predictive value of 93.4% (92.7% to 94.0%; 5431/5814). The sensitivity in participants with an RT-qPCR cycle threshold (Ct) of <18.3 (approximate viral loads >10 6 RNA copies/mL) was 90.9% (58.7% to 99.8%; 10/11), a Ct of <24.4 (>10 4 RNA copies/mL) was 69.4% (51.9% to 83.7%; 25/36), and a Ct of >24.4 (<10 4 RNA copies/mL) was 9.7% (1.9% to 23.7%; 3/34). LFT is likely to detect at least three fifths and at most 998 in every 1000 people with a positive RT-qPCR test result with high viral load. Conclusions The Innova LFT can be useful for identifying infections among adults who report no symptoms of covid-19, particularly those with high viral load who are more likely to infect others. The number of asymptomatic adults with lower Ct (indicating higher viral load) missed by LFT, although small, should be considered when using single LFT in high consequence settings. Clear and accurate communication with the public about how to interpret test results is important, given the chance of missing some cases, even at high viral loads. Further research is needed to understand how infectiousness is reflected in the viral antigen shedding detected by LFT versus the viral loads approximated by RT-qPCR.

THE PASSIVE TRANSFER OF ANTIBODIES TO ESCHERICHIA COLI 0111:B4 FROM MOTHER TO OFFSPRING

PEDIATRICS ◽  
1961 ◽  
Vol 27 (2) ◽  
pp. 308-313
Author(s):  
Sidney Sussman
Keyword(s):  
Escherichia Coli ◽  
Antibody Titer ◽  
Passive Transfer ◽  
The Third ◽  
Coli Antibody ◽  
Antibody Titers

Esch. coli antibody titers in 27 mothers and their respective offspring were studied by the trypsinated and nontrypsinated hemagglutination technic. All of the maternal sera and colostra contained Esch. coli 0111-B4 antibody. In 19 cases the antibody titer in the specimens of colostrum on the first day was higher than that of the corresponding sera. The antibody titer in the colstrum fell rapidly during the next 3 to 4 days. Five cord sera had a low antibody titer to Esch. coli 0111:B4 when tested by the trypsinated hemagglutination method. By contrast, only two cord sera were positive for Esch. coli 0111:B4 antibody when tested by the untrypsinated hemagglutination technic. With the trypsinated method, two infants showed a 2-tube rise and one infant had a 1-tube rise in titer at the end of the third colostrum day; one infant demonstrated a 1-tube rise in titer when tested by the untrypsinated hemagglutination technic. In general, there was a 1-to-3-tube difference between the trypsinated and untrypsinated hemagglutination procedures.

scholarly journals Legionnaires' disease in the renal transplant unit of "Hospital das Clinicas, FMUSP": during a five year period (1988-1993)

1994 ◽  
Vol 36 (3) ◽  
pp. 231-236 ◽  
Author(s):  
Neusa Augusta de Oliveira Mazieri ◽  
Cid Vieira Franco de Godoy ◽  
Solange Figueiredo Alves ◽  
Dahir Ramos de Andrade ◽  
Ana Sara S. Levin ◽  
...  
Keyword(s):  
Renal Transplant ◽  
Legionella Pneumophila ◽  
Treatment Interruption ◽  
Immunofluorescence Assay ◽  
High Susceptibility ◽  
Water Decontamination ◽  
Transplant Patients ◽  
Antibody Titers ◽  
Legionnaires Disease ◽  
Renal Transplant Patients

Several reports have related Legionella pneumophila with pneumonia in renal transplant patients, however this association has not been systematically documented in Brazil. Therefore this paper reports the incidence, by serologycal assays, of Legionella pneumophila serogroup 1 in these patients during a five year period. For this purpose sera from blood samples of 70 hospitalized patients with pneumonia from the Renal Transplant Unit of Hospital das Clinicas, FMUSP collected at the acute and convalescent phase of infection were submitted to indirect immunofluorescence assay (IFA) to demonstrate anti-Legionella pneumophila serogroup 1 antibodies. Of these 70 patients studied during the period of 1988 to 1993,18 (25.71 %) had significant rises in specific antibody titers for Legionella pneumophila serogroup 1. Incidence was interrupted following Hospital water decontamination procedures, with recurrence of infections after treatment interruption. In this study, the high susceptibility (25.71%) of immunodepressed renal transplant patients to Legionella pneumophila serogroup 1 nosocomial infections is documented. The importance of the implementation and maintenance of water decontamination measures for prophylaxis of the infection is also clearly evident.

scholarly journals Clinical impact of respiratory syncytial virus infection on children hospitalized for pertussis

2020 ◽  
Author(s):  
Ruimu Zhang ◽  
Jikui Deng
Keyword(s):  
Respiratory Syncytial Virus ◽  
Hospital Stay ◽  
Antibiotic Use ◽  
Immunofluorescence Assay ◽  
Clinical Impact ◽  
Chest Auscultation ◽  
Lactam Antibiotic ◽  
Rsv Infection ◽  
Polymerase Chain ◽  
Syncytial Virus

Abstract Background: Although Respiratory syncytial virus (RSV) is one of the common pathogens in children with pertussis and viral coinfection, the clinical impact of RSV infection on pertussis remains unclear. We compared clinical characteristics and sought differences between infants with single Bordetella pertussis (B. pertussis) infection and those with RSV coinfection.Methods: We enrolled 80 patients with pertussis who were hospitalized in Shenzhen Children’s Hospital from January 2017 to December 2019. Respiratory tract samples were tested for B. pertussis with real-time polymerase chain reaction and respiratory viruses with immunofluorescence assay. Clinical data were obtained from hospital records and collected using a structured questionnaire.Results: Thirty-seven of 80 patients had B. pertussis infection alone (pertussis group) and 43 had RSV-pertussis coinfection (coinfection group). No significant differences were found with regard to sex, body weight, preterm birth history, pertussis vaccination, symptoms, presence of pneumonia, or lymphocyte count between the 2 groups. Patients with RSV coinfection were older; received more β-lactam antibiotic treatment; had higher rates of wheezes and rales on chest auscultation, a higher rate of readmission, and a longer hospital stay.Conclusions: RSV coinfection increases β-lactam antibiotic use, readmission rate, and hospital stay in children hospitalized for pertussis. RSV infection should be suspected when wheezes or rales are present on auscultation of the chest in these patients. Early detection of RSV may avoid unnecessary antibiotic use.

ANTIBODY RESPONSES TO NATURALLY OCCURRING POLIOMYELITIS INFECTIONS

PEDIATRICS ◽  
1956 ◽  
Vol 17 (4) ◽  
pp. 489-502
Author(s):  
C. Arden Miller ◽  
Margaret F. Lenahan
Keyword(s):  
Diagnostic Tool ◽  
Test Procedure ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Paralytic Poliomyelitis ◽  
Repeat Testing ◽  
Household Contacts ◽  
Naturally Occurring ◽  
Antibody Titers ◽  
Fecal Virus

The neutralizing antibody responses of 52 asymptomatic household contacts of patients with poliomyelitis were studied by the metabolic inhibition method. Half of these contacts were fecal carriers of poliomyelitis virus. For purposes of comparison the antibody responses of 25 patients with paralytic poliomyelitis, all fecal virus carriers, were studied. The errors of replication of the test procedure were determined by duplicate testing of 51 serums. Duplicate testing of serum specimens indicated disagreement regarding the presence or absence of antibody in 6.0 to 8.0 per cent of the serums. The second test gave antibody titers which disagreed with those from the first test by a factor of fourfold or more 37.0 per cent of the time; errors occurred equally in either direction. Half of all persons studied showed an increase of fourfold or more in the antibody titers of paired serums; this was 3 to 4 times as many as would be expected by chance. It was not possible to distinguish the antibody responses of paralyzed patients from asymptomatic household contacts; or the fecal virus carriers from the nonvirus carriers in the latter group. Four virus carriers who did not have homologous antibody in convalescent serums were found. By repeat testing homologous antibody was found in all but one of these. The limitations of the test procedure as a diagnostic tool are discussed.

Abstract 11437: Circulating Anti-Elastin Antibody and Arterial Disease Characteristics: Association With Arterial Stiffness and Atherosclerosis

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Seung-Hyun Lee ◽  
Kihyuk Shin ◽  
Sungha Park ◽  
Seok-Min Kang ◽  
Seung-Hyo Lee ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Arterial Stiffness ◽  
Antibody Titer ◽  
Augmentation Index ◽  
Linear Regression Analysis ◽  
Arterial Disease ◽  
Control Group ◽  
Structural Protein ◽  
Antibody Titers ◽  
Artery Disease

Objectives: Elastin is a major structural protein of arteries and elastin derived peptide is known to be related to arterial change. We previously reported a novel assay for anti-aortic elastin antibody, but its clinical implication has not been clearly shown. The aim of this study was to check if anti-aortic elastin antibody titers may reflect the risk of coronary artery disease (CAD) or its detail characteristics. Methods: This study included 174 CAD patients and 171 age-, sex-matched control subjects. In all subjects, anti-aortic elastin antibody titer was quantified by ELISA. Parameters of arterial stiffness including augmentation index (AI) and heart to femoral pulse wave velocity (hfPWV) were measured non-invasively. In patients with CAD, clinical and angiographic characteristics were evaluated. Associations between anti-aortic elastin and vascular characteristics were identified by linear regression analysis. Results: Median blood level of anti-aortic elastin was significantly lower in the CAD group than that of the control group (197 a.u. vs. 63 a.u., p<0.001). Levels of anti-aortic elastin were significantly lower in males, subjects with hypertension, diabetes mellitus, hyperlipidemia, or hfPWV (Figure). However, the levels were not dependent of atherothrombotic events or angiographic severity of CAD (Figure). In multivariate analysis, male (β=-0.38, p<0.001), diabetes mellitus (β=-0.62, p<0.001), hyperlipidemia (β=-0.29, p<0.001), and AI (β=-0.006, p=0.02) were finally identified as determinants for anti-aortic elastin levels (Table). Conclusions: Taken together, lower levels of anti-aortic elastin are related to CAD. The association between antibody titer and CAD is linked to arterial stiffness rather than advancement of atherosclerosis.

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