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. 2024 Jan 8;24(1):64.
doi: 10.1186/s12879-023-08948-9.

The effectiveness and efficiency of asymptomatic SARS-CoV-2 testing strategies for patient and healthcare workers within acute NHS hospitals during an omicron-like period

Stephanie Evans  1   2 , Nichola R Naylor  3   4 , Tom Fowler  5   6 , Susan Hopkins  5   7 , Julie Robotham  5   8   6
Affiliations

The effectiveness and efficiency of asymptomatic SARS-CoV-2 testing strategies for patient and healthcare workers within acute NHS hospitals during an omicron-like period

Stephanie Evans et al. BMC Infect Dis. .

Abstract

Background: Asymptomatic SARS-CoV-2 testing of hospitalised patients began in April-2020, with twice weekly healthcare worker (HCW) testing introduced in November-2020. Guidance recommending asymptomatic testing was withdrawn in August-2022. Assessing the impact of this decision from data alone is challenging due to concurrent changes in infection prevention and control practices, community transmission rates, and a reduction in ascertainment rate from reduced testing. Computational modelling is an effective tool for estimating the impact of this change.

Methods: Using a computational model of SARS-CoV-2 transmission in an English hospital we estimate the effectiveness of several asymptomatic testing strategies, namely; (1) Symptomatic testing of patients and HCWs, (2) testing of all patients on admission with/without repeat testing on days 3 and 5-7, and (3) symptomatic testing plus twice weekly asymptomatic HCW testing with 70% compliance. We estimate the number of patient and HCW infections, HCW absences, number of tests, and tests per case averted or absence avoided, with differing community prevalence rates over a 12-week period.

Results: Testing asymptomatic patients on admission reduces the rate of nosocomial SARS-CoV-2 infection by 8.1-21.5%. Additional testing at days 3 and 5-7 post admission does not significantly reduce infection rates. Twice weekly asymptomatic HCW testing can reduce the proportion of HCWs infected by 1.0-4.4% and monthly absences by 0.4-0.8%. Testing asymptomatic patients repeatedly requires up to 5.5 million patient tests over the period, and twice weekly asymptomatic HCW testing increases the total tests to almost 30 million. The most efficient patient testing strategy (in terms of tests required to prevent a single patient infection) was testing asymptomatic patients on admission across all prevalence levels. The least efficient was repeated testing of patients with twice weekly asymptomatic HCW testing in a low prevalence scenario, and in all other prevalence levels symptomatic patient testing with regular HCW testing was least efficient.

Conclusions: Testing patients on admission can reduce the rate of nosocomial SARS-CoV-2 infection but there is little benefit of additional post-admission testing. Asymptomatic HCW testing has little incremental benefit for reducing patient cases at low prevalence but has a potential role at higher prevalence or with low community transmission. A full health-economic evaluation is required to determine the cost-effectiveness of these strategies.

Keywords: COVID-19; Lateral flow testing; Modelling.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Modelled (solid lines) and predicted (dashed lines) community prevalence (A) and hospital admissions (B). Grey lines = variation in known admissions rates between trusts from NHSE Situation Report dataset
Fig. 2
Fig. 2
Impact of asymptomatic patient testing on infections in patients and HCW populations. (A) Percentage of patients infected nosocomially over 12 weeks. (B) Percentage of HCWs infected nosocomially (dark bars) and in the community (pale bars) over 12 weeks. (C) Percentage of HCWs absent with a detected or SARS-CoV-2 infection per month. In all scenarios HCWs are tested twice weekly with 70% compliance. Bars: median, Error bars: IQR
Fig. 3
Fig. 3
Impact of twice weekly asymptomatic HCW testing on infections in patients and HCW populations. (A) Percentage of patients infected nosocomially over 12 weeks. (B) Percentage of HCWs infected nosocomially (dark bars) and in the community (pale bars) over 12 weeks. (C) Percentage of HCWs absent with a detected or SARS-CoV-2 infection per month. In both scenarios all patients are tested on admission and at days 3 and 5–7. Bars: median, Error bars: IQR
Fig. 4
Fig. 4
Efficiency of asymptomatic testing strategies. (A) Total tests required over 12-week simulation period for patients (light) and HCWs (dark). (B) Number of patient (light) and HCW (dark) infection prevented under each strategy compared to symptomatic testing only. (C) Number of tests required to prevent a single patient infection compared to symptomatic testing only. (D) Number of tests required to prevent a single HCW infection compared to symptomatic testing only
Fig. 5
Fig. 5
Sensitivity analysis. Partial-rank correlation coefficients were calculated for the number of nosocomial patient infections in the absence of asymptomatic testing (A), number of nosocomial patient infections averted when asymptomatic testing of patient and HCWs was on vs. off (B), total number of HCW infections in the absence of asymptomatic testing (C), and total number of HCW infections averted when asymptomatic testing of patient and HCWs was on vs. off (D). Simulations were carried out for a 12 week omicron-like time period of medium prevalence
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References

    1. Bhattacharya A, Collin SM, Stimson J, Thelwall S, Nsonwu O, Gerver S, et al. Healthcare-associated COVID-19 in England: a national data linkage study. J Infect. 2021;83(5):565–72. doi: 10.1016/j.jinf.2021.08.039. - DOI - PMC - PubMed
    1. Lindsey BB, Villabona-Arenas CJ, Campbell F, Keeley AJ, Parker MD, Shah DR, et al. Characterising within-hospital SARS-CoV-2 transmission events using epidemiological and viral genomic data across two pandemic waves. Nat Commun. 2022;13(1):671. doi: 10.1038/s41467-022-28291-y. - DOI - PMC - PubMed
    1. Eyre DW, Lumley SF, O’Donnell D, Campbell M, Sims E, Lawson E, et al. Differential occupational risks to healthcare workers from SARS-CoV-2: a prospective observational study. medRxiv. 2020;2020.06.24:20135038. - PMC - PubMed
    1. Hall VJ, Foulkes S, Charlett A, Atti A, Monk EJM, Simmons R, et al. SARS-CoV-2 Infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN) Lancet. 2021;17(10283):1459–69. doi: 10.1016/S0140-6736(21)00675-9. - DOI - PMC - PubMed
    1. Garrett N, Tapley A, Andriesen J, Seocharan I, Fisher LH, Bunts L et al. High asymptomatic carriage with the Omicron variant in South Africa. Clin Infect Dis. 2022. - PMC - PubMed