scholarly journals Longitudinal Follow Up of Immune Responses to SARS-CoV-2 in Health Care Workers in Sweden With Several Different Commercial IgG-Assays, Measurement of Neutralizing Antibodies and CD4+ T-Cell Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Emelie Marklund ◽  
Susannah Leach ◽  
Kristina Nyström ◽  
Anna Lundgren ◽  
Jan-Åke Liljeqvist ◽  
...  
Keyword(s):  
Health Care ◽  
T Cell ◽  
Health Care Workers ◽  
Neutralizing Antibodies ◽  
Blood Donors ◽  
Past Infection ◽  
Cell Reactivity ◽  
Time Points ◽  
Care Workers ◽  
T Cell Reactivity

BackgroundThe risk of SARS-CoV-2 infection among health care workers (HCWs) is a concern, but studies that conclusively determine whether HCWs are over-represented remain limited. Furthermore, methods used to confirm past infection vary and the immunological response after mild COVID-19 is still not well defined.Method314 HCWs were recruited from a Swedish Infectious Diseases clinic caring for COVID-19 patients. IgG antibodies were measured using two commercial assays (Abbot Architect nucleocapsid (N)-assay and YHLO iFlash-1800 N and spike (S)-assays) at five time-points, from March 2020 to January 2021, covering two pandemic waves. Seroprevalence was assessed in matched blood donors at three time-points. More extensive analyses were performed in 190 HCWs in September/October 2020, including two additional IgG-assays (DiaSorin LiaisonXL S1/S2 and Abbot Architect receptor-binding domain (RBD)-assays), neutralizing antibodies (NAbs), and CD4+ T-cell reactivity using an in-house developed in vitro whole-blood assay based on flow cytometric detection of activated cells after stimulation with Spike S1-subunit or Spike, Membrane and Nucleocapsid (SMN) overlapping peptide pools.FindingsSeroprevalence was higher among HCWs compared to sex and age-matched blood donors at all time-points. Seropositivity increased from 6.4% to 16.3% among HCWs between May 2020 and January 2021, compared to 3.6% to 11.9% among blood donors. We found significant correlations and high levels of agreement between NAbs and all four commercial IgG-assays. At 200-300 days post PCR-verified infection, there was a wide variation in sensitivity between the commercial IgG-assays, ranging from <30% in the N-assay to >90% in the RBD-assay. There was only moderate agreement between NAbs and CD4+ T-cell reactivity to S1 or SMN. Pre-existing CD4+ T-cell reactivity was present in similar proportions among HCW who subsequently became infected and those that did not.ConclusionsHCWs in COVID-19 patient care in Sweden have been infected with SARS-CoV-2 at a higher rate compared to blood donors. We demonstrate substantial variation between different IgG-assays and propose that multiple serological targets should be used to verify past infection. Our data suggest that CD4+ T-cell reactivity is not a suitable measure of past infection and does not reliably indicate protection from infection in naive individuals.

scholarly journals Differential T cell reactivity to seasonal coronaviruses and SARS-CoV-2 in community and health care workers

2021 ◽  
Author(s):  
Ricardo da Silva Antunes ◽  
Suresh Pallikkuth ◽  
Erin Williams ◽  
Esther Dawen Yu ◽  
Jose Mateus ◽  
...  
Keyword(s):  
Health Care ◽  
T Cell ◽  
Health Care Workers ◽  
Cross Reactivity ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Care Workers ◽  
Community Controls ◽  
T Cell Reactivity

AbstractHerein we measured CD4+ T cell responses against common cold corona (CCC) viruses and SARS-CoV-2 in high-risk health care workers (HCW) and community controls. We observed higher levels of CCC reactive T cells in SARS-CoV-2 seronegative HCW compared to community donors, consistent with potential higher occupational exposure of HCW to CCC. We further show that SARS-CoV-2 reactivity of seronegative HCW was higher than community controls and correlation between CCC and SARS-CoV-2 responses is consistent with cross-reactivity and not associated with recent in vivo activation. Surprisingly, CCC reactivity was decreased in SARS-CoV-2 infected HCW, suggesting that exposure to SARS-CoV-2 might interfere with CCC responses, either directly or indirectly. This result was unexpected, but consistently detected in independent cohorts derived from Miami and San Diego.

scholarly journals Differential T cell reactivity to endemic coronaviruses and SARS-CoV-2 in community and health care workers

2021 ◽  
Author(s):  
Ricardo da Silva Antunes ◽  
Suresh Pallikkuth ◽  
Erin Williams ◽  
Dawen Yu Esther ◽  
Jose Mateus ◽  
...  
Keyword(s):  
Health Care ◽  
T Cell ◽  
Health Care Workers ◽  
Cross Reactivity ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Care Workers ◽  
Community Controls ◽  
T Cell Reactivity

Abstract Herein we measured CD4 + T cell responses against common cold corona (CCC) viruses and SARS-CoV-2 in high-risk health care workers (HCW) and community controls. We observed higher levels of CCC reactive T cells in SARS-CoV-2 seronegative HCW compared to community donors, consistent with potential higher occupational exposure of HCW to CCC. We further show that SARS-CoV-2 T cell reactivity of seronegative HCW was higher than community controls and correlation between CCC and SARS-CoV-2 responses is consistent with cross-reactivity and not associated with recent in vivo activation. Surprisingly, CCC T cell reactivity was decreased in SARS-CoV-2 infected HCW, suggesting that exposure to SARS-CoV-2 might interfere with CCC responses, either directly or indirectly. This result was unexpected, but consistently detected in independent cohorts derived from Miami and San Diego.

scholarly journals Upregulation of PD-1 expression on circulating CD8+ but not CD4+ T cells is associated with tuberculosis infection in health care workers

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Cui-lin Shi ◽  
Jian-ping Zhang ◽  
Ping Xu ◽  
Jin Li ◽  
Jie Shen ◽  
...  
Keyword(s):  
Health Care ◽  
T Cells ◽  
T Cell ◽  
Health Care Workers ◽  
Cd4 T Cells ◽  
Receptor Expression ◽  
Effector Memory ◽  
Care Workers ◽  
Latent Tb ◽  
Latent Tb Infection

Abstract Background Health care workers (HCWs) are at risk for occupationally acquired Mycobacterium tuberculosis infection and tuberculosis (TB) disease due to repeated exposure to workplace tubercle bacilli. To determine whether continual mycobacterial stimulation correlates with increased expression of inhibitory T cell receptors, here we compared PD-1 receptor expression on surfaces of circulating T cells between naïve (uninfected) HCWs and HCWs with latent TB infection (LTBI). Result Data collected from 133 medical workers who met study selection criteria were included in the final analysis. QuantiFERON-TB Gold In-​Tube (QFT-GIT) testing yielded positive results for 32 HCWs, for an overall LTBI rate of 24.1%. Multivariate analysis identified HCW length of service > 15 years as an independent risk factor for a positive QFT-GIT result. In addition, comparisons of blood T cell subgroup profiles between QFT- and QFT+ groups indicated QFT+ subjects possessed greater proportions of mature (TM), transitional memory (TTM) and effector memory (TEM) CD4+ T cell subgroups and lower proportions of naïve T cells (TN). Moreover, the QFT+ group percentage of CD8+ T cells with detectable surface PD-1 was significantly higher than the corresponding percentage for the QFT- group. Meanwhile, no statistical intergroup difference was observed in percentages of CD4+ T cells with detectible surface PD-1. Conclusions Our data demonstrated that upregulated PD-1 expression on circulating CD8+, but not CD4+ T cells, was associated with latent TB infection of HCWs. As compared to other hospitals, occupational TB infection risk in our hospital was substantially mitigated by implementation of multitiered infection control measures.

scholarly journals SARS-CoV-2–Specific Neutralizing Antibody Responses in Norwegian Health Care Workers After the First Wave of COVID-19 Pandemic: A Prospective Cohort Study

2020 ◽  
Author(s):  
Mai-Chi Trieu ◽  
Amit Bansal ◽  
Anders Madsen ◽  
Fan Zhou ◽  
Marianne Sævik ◽  
...  
Keyword(s):  
Health Care ◽  
Cohort Study ◽  
Prospective Cohort Study ◽  
Health Care Workers ◽  
Prospective Cohort ◽  
Neutralizing Antibodies ◽  
Rt Pcr ◽  
Patient Exposure ◽  
Specific Antibodies ◽  
Care Workers

Abstract Background During the coronavirus disease 2019 (COVID-19) pandemic, many countries experienced infection in health care workers (HCW) due to overburdened health care systems. Whether infected HCW acquire protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Methods In a Norwegian prospective cohort study, we enrolled 607 HCW before and after the first COVID-19 wave. Exposure history, COVID-19–like symptoms, and serum samples were collected. SARS-CoV-2–specific antibodies were characterized by spike-protein IgG/IgM/IgA enzyme-linked immunosorbent and live-virus neutralization assays. Results Spike-specific IgG/IgM/IgA antibodies increased after the first wave in HCW with, but not in HCW without, COVID-19 patient exposure. Thirty-two HCW (5.3%) had spike-specific antibodies (11 seroconverted with ≥4-fold increase, 21 were seropositive at baseline). Neutralizing antibodies were found in 11 HCW that seroconverted, of whom 4 (36.4%) were asymptomatic. Ninety-seven HCW were tested by reverse transcriptase polymerase chain reaction (RT-PCR) during follow-up; 8 were positive (7 seroconverted, 1 had undetectable antibodies). Conclusions We found increases in SARS-CoV-2 neutralizing antibodies in infected HCW, especially after COVID-19 patient exposure. Our data show a low number of SARS-CoV-2–seropositive HCW in a low-prevalence setting; however, the proportion of seropositivity was higher than RT-PCR positivity, highlighting the importance of antibody testing.

scholarly journals Gamma delta T cell responses associated with the development of tuberculosis in health care workers

2005 ◽  
Vol 43 (3) ◽  
pp. 339-350 ◽  
Author(s):  
Diane J. Ordway ◽  
Luisa Pinto ◽  
Leonor Costa ◽  
Marta Martins ◽  
Clara Leandro ◽  
...  
Keyword(s):  
Health Care ◽  
T Cell ◽  
Health Care Workers ◽  
T Cell Responses ◽  
Gamma Delta ◽  
Cell Responses ◽  
Care Workers ◽  
Gamma Delta T Cell

scholarly journals A prospective study to assess the prevalence of hepatitis B infection in health care workers, voluntary blood donors, and patients with liver disorders at a tertiary care centre

2017 ◽  
Vol 6 (7) ◽  
pp. 1708
Author(s):  
Purshottam K. Kaundal ◽  
Anju Partap Kaundal
Keyword(s):  
Health Care ◽  
Hepatitis B ◽  
Health Care Workers ◽  
Blood Donors ◽  
Risk Behaviour ◽  
Liver Disorder ◽  
Hepatitis B Infection ◽  
Liver Disorders ◽  
Care Workers ◽  
High Risk Behaviour

Background: Hepatitis B virus (HBV) is highly infectious when compared with human immuno-deficiency virus (HIV), even minute quantity of infected blood as little as 0.0001 ml can transmit infection. A number of the routine therapeutic, diagnostic, prophylactic invasive procedures can spread HBV infection. The study was planned to assess the prevalence of hepatitis B surface antigen in health care workers, voluntary blood donors, and patients with liver disorders.Methods: The study was a cross sectional study carried out among 90 subjects during a period of one year in Indira Gandhi Medical College and Hospital, Shimla. These 90 subjects consisted of 30 patients with liver disorder, 30 health care workers and 30 voluntary blood donors. The blood samples were collected and sent for detection of HBsAg by ELISA.Results: Majority of the subjects 47 (52.2%) belonged to the age group of 21-30 years. Among voluntary blood donors, 90% were males. 64.4% of the subjects belonged to urban areas. 50% of the rural subjects were having liver disorders. Liver disorder was more common (71.5%) among heterosexual high risk behaviour subjects compared to only 25.7% with no high risk behaviour. Seropositivity was found highest among patients with liver disorder (66.7%) followed by health care workers (20%). Overall, the seropositivity was 28.9%.Conclusions: Patients with liver disorders especially chronic hepatitis were mostly seropositive. Among health care workers, being a doctor was a significant risk factor for acquiring hepatitis B infection. Thus, it is advised that all health care workers should be immunized for hepatitis B. 

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