URL
https://www.medrxiv.org/content/10.1101/2020.12.08.20246009v2
Type d’article
Preprint
Thème
Stratégies de contrôle
Que retenir de cet article, en 1-2 phrases ?
The potential of a (repeated) mass testing campaign is evaluated. By itself, even repeated mass testing is not enough to efficiently contain the epidemic.
Objectifs de l’étude / Questions abordées
Assessment of a mass testing strategy to contain the epidemic.
Méthode
Deterministic SEEIR model (two exposed phases: E1 non-infectious, E2 infectious).
Assumptions on testing success: probability to test positive when in compartment I and E2 is 90% (sensitivity analysis with 60% and 75%), otherwise the probability is zero.
In case of a positive test result, the transmission rate is reduced by 70% (sensitivity analysis with 50% and 90%).
Résultats principaux
The impact of mass testing on epidemic dynamics in France is quantified. Importantly, in the baseline scenario (90% probability of testing positive in case of an infection, 70% transmission reduction, 75% of the population is tested) repeated testing in an interval of 6 to 16 days, depending on the effective reproduction number (ranging from 1.2 to 1.4), is necessary to have less than 40,000 daily infections by the beginning of May. A single mass testing campaign would delay the epidemic by at most 10 days.
In conclusion, the authors argue that a single mass testing campaign will only have a limited effect on the epidemic dynamics. Repeated mass testing would be required to contain a fast growing epidemic. In combination with other epidemic containing efforts, repeated mass testing could add to the control measures. An important limitation is that, as the authors state, about 50% of individuals will still be in the latent phase E1 at the time of testing and therefore be missed. These individuals are responsible for the rebound of the epidemic after the mass testing campaign. The authors therefore suggest that for a given number of tests, the testing effort should focus on high incidence areas to best contain further spread of the virus.
Commentaire / brève évaluation, limites, ouvertures possibles
This preprint is a short note evaluating the impact of testing to inform policy makers. The results are interesting but have already been evaluated in other manuscripts (as also cited in the manuscript).