Coronavirus (COVID-19): modelling the epidemic (issue no. 47)

Key Points

• The reproduction rate R in Scotland is currently estimated as being between 0.8 and 1.0.
• The number of new daily infections for Scotland is estimated as being between 4 and 28, per 100,000 people. This is a decrease from last week.
• The growth rate for Scotland is currently estimated as being between -4% and 0%.
• Modelling on which local authority areas are exceeding what would be expected in terms of Covid-19 infections in the last seven days has recommenced, as we are below 50 cases per 100,000 people at the national level. This shows that there are currently no local authority areas exceeding what we would expect over the last seven days.
• Average contacts are still higher than seen during the lockdown period (averaging around 3 daily contacts) but have decreased slightly in the last two weeks, with a current level of 3.5 daily contacts.
• Contacts within the work and school setting have shown a decrease in the last two weeks by 25% and 36% respectively, coinciding with spring holidays that commenced from 26^th March.
• Mean contacts in the home setting have increased by approximately 16% over the same period.
• Those aged under 50 have shown a decrease in overall contacts whereas those aged 50 and over have increased their contacts
• The 30-49 age group has reported a decrease in contacts within the school and work place. This coincides with a decrease shown in the interactions between this age group and individuals under 18.
• The number of participants visiting different locations has remained at a similar level since January with the exception of those who have visited another's home, increasing from 21% in January to 38% in the most recent survey.
• Although the older population have increased their contacts in the last two weeks, daily cases and deaths have declined over the same period.
• Hospital bed and ICU occupancy are projected to fall over the next few weeks, but these both may plateau or increase as a result of schools reopening and other relaxations of non-pharmaceutical interventions.
• Modelled rates per 100K indicate that for the week commencing 25 April 2021, no local authorities have at least a 75% probability of exceeding 50 cases. In last week's issue of these Research Findings, 4 local authorities had a 75% or higher probability of exceeding 50 cases per 100K.
• The overall level of wastewater Covid-19 this week was similar to last week, consistent with a slow decline in the rate of new cases.