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. 2023 Mar;28(13):2200432.
doi: 10.2807/1560-7917.ES.2023.28.13.2200432.

At-home sampling to meet geographical challenges for serological assessment of SARS-CoV-2 exposure in a rural region of northern Sweden, March to May 2021: a retrospective cohort study

Affiliations

At-home sampling to meet geographical challenges for serological assessment of SARS-CoV-2 exposure in a rural region of northern Sweden, March to May 2021: a retrospective cohort study

Julia Wigren Byström et al. Euro Surveill. 2023 Mar.

Abstract

BackgroundThe current SARS-CoV-2 pandemic has highlighted a need for easy and safe blood sampling in combination with accurate serological methodology. Venipuncture for testing is usually performed by trained staff at healthcare centres. Long travel distances to healthcare centres in rural regions may introduce a bias of testing towards relatively large communities with closer access. Rural regions are therefore often not represented in population-based data.AimThe aim of this retrospective cohort study was to develop and implement a strategy for at-home testing in a rural region of Sweden during spring 2021, and to evaluate its role to provide equal health care for its inhabitants.MethodsWe developed a sensitive method to measure antibodies to the S-protein of SARS-CoV-2 and optimised this assay for clinical use together with a strategy of at-home capillary blood sampling.ResultsWe demonstrated that our ELISA gave comparable results after analysis of capillary blood or serum from SARS-CoV-2-experienced individuals. We demonstrated stability of the assay under conditions that reflected temperature and humidity during winter or summer. By assessment of capillary blood samples from 4,122 individuals, we could show both feasibility of the strategy and that implementation shifted the geographical spread of testing in favour of rural areas.ConclusionImplementation of at-home sampling enabled citizens living in remote rural areas access to centralised and sensitive laboratory antibody tests. The strategy for testing used here could therefore enable disease control authorities to get rapid access to information concerning immunity to infectious diseases, even across vast geographical distance.

Keywords: Sweden; coronavirus disease (COVID-19); laboratory; surveillance.

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Conflict of interest statement

Conflict of interest: JWB, JN and MF are founders and shareholders of the diagnostic company Xerum AB that provided funds towards this project via grants from the Swedish Innovations Agency, Vinnova.

Figures

Figure 1
Figure 1
Validation of ELISA methodology to detect binding and neutralising anti-SARS-CoV-2 S-specific IgG, Region Västerbotten, Sweden, March–May 2020
Figure 2
Figure 2
Verification of at-home capillary blood self-sampling test methodology, Region Västerbotten, Sweden, September–November 2020
Figure 3
Figure 3
At-home SARS-CoV-2 serology testing of the population using dried blood spot sampling kits in Region Västerbotten, Sweden, March−May 2021 (n = 4,122)
Figure 4
Figure 4
Access to SARS-CoV-2 serological testing in Region Västerbotten, Sweden, by venous blood sampling, November 2020–January 2021 (n = 8,002) and dried blood spot self-sampling, March−May 2021 (n = 4,122)

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References

    1. Milne G, Hames T, Scotton C, Gent N, Johnsen A, Anderson RM, et al. Does infection with or vaccination against SARS-CoV-2 lead to lasting immunity? Lancet Respir Med. 2021;9(12):1450-66. 10.1016/S2213-2600(21)00407-0 - DOI - PMC - PubMed
    1. Altarawneh HN, Chemaitelly H, Hasan MR, Ayoub HH, Qassim S, AlMukdad S, et al. Protection against the Omicron variant from previous SARS-CoV-2 infection. N Engl J Med. 2022;386(13):1288-90. 10.1056/NEJMc2200133 - DOI - PMC - PubMed
    1. Folkhälsomyndigheten (FoHM). Teststrategi för covid-19 under 2021. [Testing strategy för covid-19 during 2021]. Stockholm: FoHM. [Accessed: 9 Feb 2023]. Swedish. Available from: https://www.folkhalsomyndigheten.se/contentassets/a1c9634c15dd487e8a8575...
    1. Michlmayr D, Hansen CH, Gubbels SM, Valentiner-Branth P, Bager P, Obel N, et al. Observed protection against SARS-CoV-2 reinfection following a primary infection: A Danish cohort study among unvaccinated using two years of nationwide PCR-test data. Lancet Reg Health Eur. 2022;20:100452. 10.1016/j.lanepe.2022.100452 - DOI - PMC - PubMed
    1. Hansen CH, Friis NU, Bager P, Stegger M, Fonager J, Fomsgaard A, et al. Risk of reinfection, vaccine protection, and severity of infection with the BA.5 omicron subvariant: a nation-wide population-based study in Denmark. Lancet Infect Dis. 2023;23(2):167-76. 10.1016/S1473-3099(22)00595-3 - DOI - PMC - PubMed

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