scholarly journals Immunoglobulin (Ig)A seropositivity against SARS-CoV-2 in healthcare workers in Israel, 4 April to 13 July 2020: an observational study

2021 ◽  
Vol 26 (48) ◽  
Author(s):  
Yaniv Lustig ◽  
Carmit Cohen ◽  
Asaf Biber ◽  
Hanaa Jaber ◽  
Yael Becker Ilany ◽  
...  

Introduction The COVID-19 pandemic has put healthcare workers (HCW) at significant risk. Presence of antibodies can confirm prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Aim This study investigates the prevalence of IgA and IgG antibodies against SARS-CoV-2 in HCW. Methods Performance of IgA and IgG antibody ELISA assays were initially evaluated in positive and negative SARS-CoV-2 serum samples. IgA and IgG antibodies against SARS-CoV-2 were measured in 428 asymptomatic HCW. We assessed the risk of two groups: HCW with high exposure risk outside work (HROW) residing in areas where COVID-19 was endemic (n = 162) and HCW with high exposure risk at work (HRAW) in a COVID-19 intensive care unit (ICU) (n = 97). Results Sensitivities of 80% and 81.2% and specificities of 97.2% and 98% were observed for IgA and IgG antibodies, respectively. Of the 428 HCW, three were positive for IgG and 27 for IgA. Only 3/27 (11%) IgA-positive HCW had IgG antibodies compared with 50/62 (81%) in a group of previous SARS-CoV-2-PCR-positive individuals. Consecutive samples from IgA-positive HCW demonstrated IgA persistence 18–83 days in 12/20 samples and IgG seroconversion in 1/20 samples. IgA antibodies were present in 8.6% of HROW and 2% of HRAW. Conclusions SARS-CoV-2 exposure may lead to asymptomatic transient IgA response without IgG seroconversion. The significance of these findings needs further study. Out of work exposure is a possible risk of SARS-CoV-2 infection in HCW and infection in HCW can be controlled if adequate protective equipment is implemented.

Author(s):  
Mayce Mansour ◽  
Emily Levin ◽  
Kimberly Muellers ◽  
Kimberly Stone ◽  
Rao Mendu ◽  
...  

Background: SARS-CoV-2 antibody testing is important for understanding immunity prevalence, and may have implications for healthcare workers (HCW) during the SARS-CoV-2 pandemic. Methods: We conducted immunologic testing of healthcare workers to determine the prevalence of SARS-CoV-2 IgG in this population. HCW were advised to wait at least two weeks from time of symptom onset or suspected exposure before undergoing testing. All participants were self-reported asymptomatic for at least three days at the time of testing. Results: Two hundred eighty-five samples were collected from March 24, 2020 to April 4, 2020. The average age of participants was 38 years (range 18-84), and 54% were male. Thirty-three percept tested IgG positive, 3% tested weakly positive, and 64% tested negative. Neither age nor sex was associated with antibody development. Conclusion: Thirty-six percent of HCW had IgG antibodies to SARS-CoV-2, reflecting the high exposure of inpatient and ambulatory frontline staff to this viral illness, most of whom had minimal symptoms and were working in the weeks preceding testing. While we continue to recommend standard protective precautions per CDC guidelines for all HCW, HCW with SARS-CoV-2 IgG may become our safest frontline providers as we learn if our IgG antibodies confer immunity. Knowing IgG antibody status may ease concerns regarding personal risk as this pandemic continues.


2003 ◽  
Vol 10 (6) ◽  
pp. 1043-1050 ◽  
Author(s):  
Ketil Moen ◽  
Johan G. Brun ◽  
Tor Magne Madland ◽  
Turid Tynning ◽  
Roland Jonsson

ABSTRACT The objective of the present study was to investigate immunoglobulin G (IgG) and IgA antibody immune responses to Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, and Candida albicans in the sera of patients with rheumatoid arthritis (RA), the synovial fluid (SF) of patients with RA (RA-SF samples), and the SF of patients without RA (non-RA-SF samples). An enzyme-linked immunosorbent assay was used to determine IgG and IgA antibody levels in 116 serum samples from patients with RA, 52 RA-SF samples, and 43 non-RA-SF samples; and these were compared with those in SF samples from 9 patients with osteoarthritis (OA-SF samples) and the blood from 100 donors (the control [CTR] group). Higher levels of IgG antibodies against B. forsythus (P < 0.0001) and P. intermedia (P < 0.0001) were found in non-RA-SF samples than in OA-SF samples, and higher levels of IgG antibodies against B. forsythus (P = 0.003) and P. intermedia (P = 0.024) were found in RA-SF samples than in OA-SF samples. Significantly higher levels of IgA antibodies against B. forsythus were demonstrated in both RA-SF and non-RA-SF samples than in OA-SF samples. When corrected for total Ig levels, levels of IgG antibody against B. forsythus were elevated in RA-SF and non-RA-SF samples compared to those in OA-SF samples. Lower levels of Ig antibodies against B. forsythus were found in the sera of patients with RA than in the plasma of the CTR group for both IgG (P = 0.003) and IgA (P < 0.0001). When corrected for total Ig levels, the levels of IgG and IgA antibodies against B. forsythus were still found to be lower in the sera from patients with RA than in the plasma of the CTR group (P < 0.0001). The levels of antibodies against P. gingivalis and C. albicans in the sera and SF of RA and non-RA patients were comparable to those found in the respective controls. The levels of IgG and IgA antibodies against B. forsythus were elevated in SF from patients with RA and non-RA-SF samples compared to those in OA-SF samples. Significantly lower levels of IgG and IgA antibodies against B. forsythus were found in the sera of patients with RA than in the plasma of the CTR group. This indicates the presence of an active antibody response in synovial tissue and illustrates a potential connection between periodontal and joint diseases.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241164 ◽  
Author(s):  
Victoria Indenbaum ◽  
Ravit Koren ◽  
Shiri Katz-Likvornik ◽  
Mayan Yitzchaki ◽  
Osnat Halpern ◽  
...  

The COVID-19 pandemic and the fast global spread of the disease resulted in unprecedented decline in world trade and travel. A critical priority is, therefore, to quickly develop serological diagnostic capacity and identify individuals with past exposure to SARS-CoV-2. In this study serum samples obtained from 309 persons infected by SARS-CoV-2 and 324 of healthy, uninfected individuals as well as serum from 7 COVID-19 patients with 4–7 samples each ranging between 1–92 days post first positive PCR were tested by an “in house” ELISA which detects IgM, IgA and IgG antibodies against the receptor binding domain (RBD) of SARS-CoV-2. Sensitivity of 47%, 80% and 88% and specificity of 100%, 98% and 98% in detection of IgM, IgA and IgG antibodies, respectively, were observed. IgG antibody levels against the RBD were demonstrated to be up regulated between 1–7 days after COVID-19 detection, earlier than both IgM and IgA antibodies. Study of the antibody kinetics of seven COVID 19 patients revealed that while IgG levels are high and maintained for at least 3 months, IgM and IgA levels decline after a 35–50 days following infection. Altogether, these results highlight the usefulness of the RBD based ELISA, which is both easy and cheap to prepare, to identify COVID-19 patients even at the acute phase. Most importantly our results demonstrate that measuring IgG levels alone is both sufficient and necessary to diagnose past exposure to SARS-CoV-2.


2009 ◽  
Vol 7 (3) ◽  
pp. 139-144
Author(s):  
D. Chatzidimitriou ◽  
M. Exidari ◽  
G. Gioula ◽  
P. Papakonstantinou ◽  
A. Melidou ◽  
...  

The prevalence of IgG and IgA antibodies to Chlamydia pneumoniae was evaluated in a group of an apparently healthy population in northern Greece. Serum samples were obtained over a period of one year (June 2006 to May 2007) from 530 individuals (300 males and 230 females, aged from 1 month to 90 years). The sera were tested for specific antibodies to C. pneumoniae by two commercial methods, an ELISA and a micro-IF assay based on the principles of MIF. The prevalence of IgG and IgA antibodies to C. pneumoniae was 53.2% and 45.9%, respectively, and was found to be unrelated to gender, even in the elderly >61 years old. The IgG antibody prevalence was low in children under 5 years old (7.7%), sharply increased by the age of 20 (40%) and continued to increase, gradually, to reach 80.1% in the elderly. IgA antibodies also increased with similar kinetics to IgG, although at a lower level (3.8–66.1%). Our results show that infection with C. pneumoniae is common in northern Greece. The high prevalence of IgA specific antibodies reported in the present study is due to primary infection at a young age, while in the elderly is probably due to infection or reinfection, although the option of persistence cannot be excluded.


2020 ◽  
Vol 14 (1) ◽  
pp. 47-52
Author(s):  
Md Shariful Alam Jilani ◽  
Tang Thean Hock ◽  
Sraboni Mazumder ◽  
Fahmida Rahman ◽  
Md Mohiuddin ◽  
...  

Background and objectives: Several types of Burkholderia pseudomallei antigens have been used to determine the antibody response in acute and asymptomatic cases. In the present study, we have detected immunoglobulin G (IgG) antibody to recombinant truncated flagellin antigen (RTFA) of B. pseudomallei in the sera of acute melioidosis cases and healthy individuals from melioidosis endemic areas of Bangladesh by indirect enzyme-linked immunosorbent assay (ELISA). In parallel, IgG antibody to sonicated whole cell antigen (SWCA) of B. pseudomallei was determined to compare with anti-RTFA antibody. Methodology: Serum samples from culture confirmed melioidosis cases and from healthy individuals aged 21 years and above residing in melioidosis endemic rural areas were included in the study. Serum IgG antibody to RTFA and SWCA of B. pseudomallei was determined by indirect ELISA. Results: Out of 8 culture confirmed acute melioidosis cases, 7 (87.5%) and 8 (100%) were positive for anti-B. pseudomallei IgG antibodies by RTFA and SWCA methods respectively. Among 361 healthy individuals, the rate of seropositivity by RTFA-ELISA was significantly less than that of SWCA-ELISA (16.1% versus 26.8%; p = 0.001). The mean optical density (OD) of RTFA-ELISA of positive cases was significantly less than that of SWCA-ELISA in both melioidosis and healthy individuals (0.79±0.11 versus 2.4±0.08, p = 0.0001; 0.67±0.01 versus 1.27±0.02, p = 0.0001). The sensitivity and specificity of RTFA-ELISA were 88.9% and 100% respectively. Conclusion: Findings of the study suggest that multiple or combination of antigens should be used to study the seroprevalence of B. pseudomallei infection in a community. Also, prospective study is necessary to find out the duration of persistence of antibodies to different antigenic components of B. pseudomallei after exposure. Ibrahim Med. Coll. J. 2020; 14(1): 47-52


2021 ◽  
Author(s):  
M R Shincy ◽  
Vandana Govindan ◽  
H H Sudhakar ◽  
V T Venkatesha ◽  
K Padmapriya ◽  
...  

ABSTRACTBackgroundMedical professionals and researchers have been urging the need for wide and rapid testing of citizens in order to plan measures that can contain the spread of the virus. Antibody tests play an important role throughout the patient care pathway and are vital for the management and surveillance of the virus. Although RT-PCR is considered as the gold standard, serological tests based on antibodies are helpful for on-time detection. We performed one to one assessment of point-of-care lateral flow assay (POCTs), enzyme immunoassay (EIAs), electrochemiluminescence immunoassay (CLIA), to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibody.Materials and Methods611 healthcare workers were recruited between November and December 2020 at Central Research Laboratory, KIMS. Collected serum samples were analysed according to manufacturer’s protocol. The Standard Q IgG/IgM combo assay, Anti-SARS CoV-2 Human IgG ELISA, and the Elecsys® to measure the IgG titer of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).ResultsThe kits displayed a sensitivity of 61.2%,79.5%, 91.8% and specificity of 61.7%,64.1%,80.2% for the Standard Q IgG/IgM combo assay, Anti-SARS CoV-2 Human IgG ELISA, and the Elecsys® in order.ConclusionOur results indicate high sensitivity and specificity for the Elecsys® assay compared to Anti-SARS CoV-2 Human IgG ELISA, the Standard Q IgG/IgM combo assay.


2020 ◽  
Author(s):  
Fang Hu ◽  
Xiaoling Shang ◽  
Meizhou Chen ◽  
Changliang Zhang

AbstractBackgroundThis study was aimed to investigate the application of SARS- COV-2 IgM and IgG antibodies in diagnosis of COVID-19 infection.MethodThis study enrolled a total of 178 patients at Huangshi Central Hospital from January to February, 2020. Among them, 68 patients were SARS-COV-2 infected confirmed with nucleic acid test (NAT) and CT imaging. 9 patients were in the suspected group (NAT negative) with fever and other respiratory symptoms. 101 patients were in the control group with other diseases and negative to SARS-COV-2 infection. After serum samples were collected, SARS-COV-2 IgG and IgM antibodies were tested by chemiluminescence immunoassay (CLIA) for all patients.ResultsThe specificity of serum IgM and IgG antibodies to SARS-COV-2 were 99.01% (100/101) and 96.04% (97/101) respectively, and the sensitivity were 88.24% (60/68) and 97.06% (66/68) respectively. The combined detection rate of SARS-COV-2 IgM and IgG antibodies were 98.53% (67/68).ConclusionCombined detection of serum SARS-COV-2 IgM and IgG antibodies had better sensitivity compared with single IgM or IgG test, which can be used as an important diagnostic tool for SARS-COV-2 infection and a screening tool of potential SARS-COV-2 carriers in clinics, hospitals and accredited scientific laboratory.


Author(s):  
Fang Hu ◽  
Xiaoling Shang ◽  
Meizhou Chen ◽  
Changliang Zhang

Background. This study was aimed to investigate the application of SARS-CoV-2 IgM and IgG antibodies in diagnosis of COVID-19 infection. Method. This study enrolled a total of 178 patients at Huangshi Central Hospital from January to February 2020. Among them, 68 patients were SARS-CoV-2 infected, confirmed with nucleic acid test (NAT) and CT imaging. Nine patients were in the suspected group (NAT negative) with fever and other respiratory symptoms. 101 patients were in the control group with other diseases and negative to SARS-CoV-2 infection. After serum samples were collected, SARS-CoV-2 IgG and IgM antibodies were tested by chemiluminescence immunoassay (CLIA) for all patients. Results. The specificity of serum IgM and IgG antibodies to SARS-CoV-2 was 99.01% (100/101) and 96.04% (97/101), respectively, and the sensitivity was 88.24% (60/68) and 97.06% (66/68), respectively. The combined detection rate of SARS-CoV-2 IgM and IgG antibodies was 98.53% (67/68). Conclusion. Combined detection of serum SARS-CoV-2 IgM and IgG antibodies had better sensitivity compared with single IgM or IgG antibody testing, which can be used as an important diagnostic tool for SARS-CoV-2 infection and a screening tool of potential SARS-CoV-2 carriers in clinics, hospitals, and accredited scientific laboratories.


2020 ◽  
Vol 8 ◽  
Author(s):  
Kohei Fujita ◽  
Shinpei Kada ◽  
Osamu Kanai ◽  
Hiroaki Hata ◽  
Takao Odagaki ◽  
...  

Background: The coronavirus disease-2019 (COVID-19) pandemic is associated with a heavy burden on the mental and physical health of patients, regional healthcare resources, and global economic activity. While understanding of the incidence and case-fatality rates has increased, there are limited data concerning seroprevalence of antibodies against the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in healthcare workers during the pre-pandemic period. This study aimed to quantitatively evaluate seroprevalence of SARS-CoV-2 antibodies in healthcare workers in the southern part of Kyoto city, Japan.Methods: We prospectively recruited healthcare workers from a single hospital between April 10 and April 20, 2020. We collected serum samples from these participants and quantitatively evaluated SARS-CoV-2 IgG antibody levels using enzyme-linked immunosorbent assays.Results: Five (5.4%), 15 (16.3%), and 72 (78.3%) participants showed positive, borderline, and negative serum SARS-CoV-2 IgG antibody status, respectively. We found the mean titer associated with each antibody status (overall, positive, borderline, and negative) was clearly differentiated. Participants working at the otolaryngology department and/or with a history of seasonal common cold symptoms had a significantly higher SARS-CoV-2 IgG antibody titer (p = 0.046, p = 0.046, respectively).Conclusions: Five (5.4%) and 15 (16.3%) participants tested positive and borderline, respectively, for SARS-CoV-2 IgG antibody during the COVID-19 pre-pandemic period. These rates were higher than expected, based on government situation reports. These findings suggest that COVID-19 had already spread within the southern part of Kyoto city at the early stage of the pandemic.


2005 ◽  
Vol 79 (20) ◽  
pp. 13186-13189 ◽  
Author(s):  
James E. Cummins ◽  
Roumiana S. Boneva ◽  
William M. Switzer ◽  
Logan L. Christensen ◽  
Paul Sandstrom ◽  
...  

ABSTRACT Simian foamy virus (SFV) infection and the subsequent immune response are not well characterized. Blood plasma, saliva, and urine were obtained from four humans and nine chimpanzees persistently infected with chimpanzee-type SFV for an unknown length of time. SFV-specific immunoglobulin G (IgG) antibodies, but not IgA antibodies, against the Gag and Bet proteins were detected, by Western blotting, in all sample types from infected humans and chimpanzees. Overall, chimpanzee samples had higher anti-SFV IgG titers than humans. These results provide a first comparative evaluation of SFV-specific host mucosal humoral immunity in infected humans and chimpanzees that is characterized by a predominant IgG response and a virtually absent IgA response.


Sign in / Sign up

Export Citation Format

Share Document