Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levels
Abstract Background Asymptomatic SARS-CoV-2 infection occurring in RT-PCR negative individuals represent a poorly characterized cohort with important infection control connotations. While household and community-based studies have evaluated seroprevalence of antibody and transmission dynamics in thi...
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| Format: | Article |
| Language: | English |
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BMC
2022-10-01
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| Series: | BMC Public Health |
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| Online Access: | https://doi.org/10.1186/s12889-022-14381-5 |
| _version_ | 1811335189529362432 |
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| author | Ridma P Karunathilake Sameera Hewage Gihani Vidanapathirana Athula Kumara Prabhath Ranasinghe Faseeha Noordeen Indika Gawarammana Champa N Ratnatunga |
| author_facet | Ridma P Karunathilake Sameera Hewage Gihani Vidanapathirana Athula Kumara Prabhath Ranasinghe Faseeha Noordeen Indika Gawarammana Champa N Ratnatunga |
| author_sort | Ridma P Karunathilake |
| collection | DOAJ |
| description | Abstract Background Asymptomatic SARS-CoV-2 infection occurring in RT-PCR negative individuals represent a poorly characterized cohort with important infection control connotations. While household and community-based studies have evaluated seroprevalence of antibody and transmission dynamics in this group, workplace-based data is currently unavailable. Methods A cohort study was carried out in July 2021, during and immediately following the peak of the 3rd wave of COVID-19 in Sri Lanka, prior to mass vaccination. A total of 92 unvaccinated individuals between the ages of 17–65 years were purposively sampled from an office and two factory settings. The selected cohort that had been exposed to RT-PCR positive cases in the workplace was tested RT-PCR negative. Serological samples collected six weeks post exposure were tested for anti-SARS-CoV-2 neutralizing antibody. Results The seroprevalence for SARS-CoV-2 specific neutralizing antibodies in the overall cohort was 63.04% (58/92). Seroprevalences in the office setting, factory setting 1 and factory setting 2 were 69.2% (9/13), 55.7% (34/61) and 83.33% (15/18), respectively. Primary risk factor associated with seropositivity was face to face contact with no mask for > 15 min (p < 0.024, Odds Ratio (OR); 5.58, 95%CI;1.292– 25.65). Individuals with workspace exposure had significantly higher levels of neutralizing antibodies than those who did not (percentage neutralization in assay 63.3% (SD:21)vs 45.7% (SD:20), p = 0.0042), as did individuals who engaged socially without protective measures (62.4 (SD:21.6)% vs 49.7 (SD:21)%, p = 0.026). Conclusion There was a high seroprevalence for SARS-CoV-2 specific neutralizing antibodies among RT-PCR negative contacts in workplace settings in Sri Lanka. Higher levels of transmission of SARS-CoV-2 infection than estimated based on RT-PCR positive contact data indicate need for targeted infection control measures in these settings during future outbreaks. |
| first_indexed | 2024-04-13T17:20:29Z |
| format | Article |
| id | doaj.art-7254e14c36f34e009806a41ddb755dbe |
| institution | Directory Open Access Journal |
| issn | 1471-2458 |
| language | English |
| last_indexed | 2024-04-13T17:20:29Z |
| publishDate | 2022-10-01 |
| publisher | BMC |
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| series | BMC Public Health |
| spelling | doaj.art-7254e14c36f34e009806a41ddb755dbe2022-12-22T02:38:00ZengBMCBMC Public Health1471-24582022-10-0122111210.1186/s12889-022-14381-5Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levelsRidma P Karunathilake0Sameera Hewage1Gihani Vidanapathirana2Athula Kumara3Prabhath Ranasinghe4Faseeha Noordeen5Indika Gawarammana6Champa N Ratnatunga7Department of Microbiology, Faculty of Medicine, University of PeradeniyaOffice of the Regional Director of Health ServicesDepartment of Microbiology, Faculty of Medicine, University of PeradeniyaDepartment of Microbiology, Faculty of Medicine, University of PeradeniyaProvincial Department of Health ServicesDepartment of Microbiology, Faculty of Medicine, University of PeradeniyaDepartment of Medicine, Faculty of Medicine, University of PeradeniyaDepartment of Microbiology, Faculty of Medicine, University of PeradeniyaAbstract Background Asymptomatic SARS-CoV-2 infection occurring in RT-PCR negative individuals represent a poorly characterized cohort with important infection control connotations. While household and community-based studies have evaluated seroprevalence of antibody and transmission dynamics in this group, workplace-based data is currently unavailable. Methods A cohort study was carried out in July 2021, during and immediately following the peak of the 3rd wave of COVID-19 in Sri Lanka, prior to mass vaccination. A total of 92 unvaccinated individuals between the ages of 17–65 years were purposively sampled from an office and two factory settings. The selected cohort that had been exposed to RT-PCR positive cases in the workplace was tested RT-PCR negative. Serological samples collected six weeks post exposure were tested for anti-SARS-CoV-2 neutralizing antibody. Results The seroprevalence for SARS-CoV-2 specific neutralizing antibodies in the overall cohort was 63.04% (58/92). Seroprevalences in the office setting, factory setting 1 and factory setting 2 were 69.2% (9/13), 55.7% (34/61) and 83.33% (15/18), respectively. Primary risk factor associated with seropositivity was face to face contact with no mask for > 15 min (p < 0.024, Odds Ratio (OR); 5.58, 95%CI;1.292– 25.65). Individuals with workspace exposure had significantly higher levels of neutralizing antibodies than those who did not (percentage neutralization in assay 63.3% (SD:21)vs 45.7% (SD:20), p = 0.0042), as did individuals who engaged socially without protective measures (62.4 (SD:21.6)% vs 49.7 (SD:21)%, p = 0.026). Conclusion There was a high seroprevalence for SARS-CoV-2 specific neutralizing antibodies among RT-PCR negative contacts in workplace settings in Sri Lanka. Higher levels of transmission of SARS-CoV-2 infection than estimated based on RT-PCR positive contact data indicate need for targeted infection control measures in these settings during future outbreaks.https://doi.org/10.1186/s12889-022-14381-5COVID-19Workplace settingsPCR negative contactsNeutralizing antibodiesRisk factors |
| spellingShingle | Ridma P Karunathilake Sameera Hewage Gihani Vidanapathirana Athula Kumara Prabhath Ranasinghe Faseeha Noordeen Indika Gawarammana Champa N Ratnatunga Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levels BMC Public Health COVID-19 Workplace settings PCR negative contacts Neutralizing antibodies Risk factors |
| title | Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levels |
| title_full | Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levels |
| title_fullStr | Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levels |
| title_full_unstemmed | Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levels |
| title_short | Pre-vaccination RT-PCR negative contacts in workplace settings show high, SARS COV-2 neutralizing antibody levels |
| title_sort | pre vaccination rt pcr negative contacts in workplace settings show high sars cov 2 neutralizing antibody levels |
| topic | COVID-19 Workplace settings PCR negative contacts Neutralizing antibodies Risk factors |
| url | https://doi.org/10.1186/s12889-022-14381-5 |
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