Direct and indirect effects of the covid-19 pandemic and response in South Asia

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Chapter 2

Methods

National projections under the various interventions were then carried out running the simulation for one year out starting from September 1st, 2020, using the calibrated parameter values as well as the estimated number of symptomatic, asymptomatic and quarantined and recovered cases obtained at the end of the calibration period. The set of interventions included:

• Smart lockdowns,
• Use of face masks, and
• Hand hygiene

All interventions were assumed to have been applied at present at the 25% adherence level, and the simulation study compared a baseline scenario – in which no further intervention was applied – to scenarios where one intervention at a time was raised to the 50% adherence level, as well as a combination off all different intervention applied at once.

The relative reductions in key inputs, as appearing in Supplementary Table 2, are presented in Table 3 below.

Table 3: Effect estimates for selected interventions aimed at reducing the relative risk of exposure and transmission of COVID-19 and other reparatory viruses

Figure 4: Transition diagram of the extended SIR compartment model. This figure illustrates the transitions between compartments denoted in each box: S- susceptible individuals; E- asymptomatic infectious patients; I - symptomatic infectious patients; Q – self-iso- lated infectious patients; H – patients requiring hospitalization;

R – COVID-19 recovered patients; and F – case fatalities due to COVID-19.