A modelling framework to assess the likely effectiveness of facemasks in combination with ‘lock-down’ in managing the COVID-19 pandemic

Abstract

COVID-19 is characterized by an infectious pre-symptomatic period, when newly infected individuals can unwittingly infect others. We are interested in what benefits facemasks could offer as a non-pharmaceutical intervention, especially in the settings where high-technology interventions, such as contact tracing using mobile apps or rapid case detection via molecular tests, are not sustainable. Here, we report the results of two mathematical models and show that facemask use by the public could make a major contribution to reducing the impact of the COVID-19 pandemic. Our intention is to provide a simple modelling framework to examine the dynamics of COVID-19 epidemics when facemasks are worn by the public, with or without imposed ‘lock-down’ periods. Our results are illustrated for a number of plausible values for parameter ranges describing epidemiological processes and mechanistic properties of facemasks, in the absence of current measurements for these values. We show that, when facemasks are used by the public all the time (not just from when symptoms first appear), the effective reproduction number, R e , can be decreased below 1, leading to the mitigation of epidemic spread. Under certain conditions, when lock-down periods are implemented in combination with 100% facemask use, there is vastly less disease spread, secondary and tertiary waves are flattened and the epidemic is brought under control. The effect occurs even when it is assumed that facemasks are only 50% effective at capturing exhaled virus inoculum with an equal or lower efficiency on inhalation. Facemask use by the public has been suggested to be ineffective because wearers may touch their faces more often, thus increasing the probability of contracting COVID-19. For completeness, our models show that facemask adoption provides population-level benefits, even in circumstances where wearers are placed at increased risk. At the time of writing, facemask use by the public has not been recommended in many countries, but a recommendation for wearing face-coverings has just been announced for Scotland. Even if facemask use began after the start of the first lock-down period, our results show that benefits could still accrue by reducing the risk of the occurrence of further COVID-19 waves. We examine the effects of different rates of facemask adoption without lock-down periods and show that, even at lower levels of adoption, benefits accrue to the facemask wearers. These analyses may explain why some countries, where adoption of facemask use by the public is around 100%, have experienced significantly lower rates of COVID-19 spread and associated deaths. We conclude that facemask use by the public, when used in combination with physical distancing or periods of lock-down, may provide an acceptable way of managing the COVID-19 pandemic and re-opening economic activity. These results are relevant to the developed as well as the developing world, where large numbers of people are resource poor, but fabrication of home-made, effective facemasks is possible. A key message from our analyses to aid the widespread adoption of facemasks would be: ‘my mask protects you, your mask protects me’.

Perception of and Anxiety About COVID-19 Infection and Risk Behaviors for Spreading Infection: An International Comparison

“…19 Another recent study described the e cacy of medical mask-wearing by asymptomatic individuals as well as lockdown at the population level. 20 We observed that the participants in Japan were signi cantly less likely to engage in any of the avoidance behaviors examined compared to those in Spain and the UK. These results were are similar to those of the other surveys conducted concurrently.…”

A fractional order approach to modeling and simulations of the novel COVID-19

“…The effects of the fractional orders are distinctive; the solution curves for 0 < α < 1 show delay in the epidemic peak and flatten faster, see Figure 5 (a), (c) and (d). These observations are known to occur in epidemic models with intervention [67]. The impacts of α is even more pronounced for smaller orders; for example, compare α = 0.9 and α = 0.6 in Figure 5 (c).…”

Covid-19 in Latin America countries: Course of the pandemic and the different responses towards control

“…From the results of the present study, it is clear that, in addition to structural factors related to material living conditions and the mechanisms of discrimination in access to healthcare resources, even with the lack of government actions or ambiguity with respect to those actions, behavioral factors can affect compliance with social distancing measures, as shown by the reduction in social mobility in Nicaragua or even in Brazil or Mexico. Another aspect that merits investigation is the contribution of the widespread use of facemasks in the epidemic in Latin America, which, alone or in combination with lockdown, has been indicated as having great potential to reduce the transmission of COVID-19 [67,68].…”