Week 8 Flashcards
What are mathmatical models?
Using mean, median, mode etc
To model relationships and differences
What is the function of models?
To help us understand:
Past
Present
Future
What is an example of models for understanding the past?
Used to estimate the effects of non-phamaceutical interventions on COVID-19 in Europe?
What was the estimated effect of non-phamaceutical interventions on COVID-19 in Europe?
Lockdowns- ~80 reduction in transmissions
Reducing public events, school closure, self isolation and social distancing all around 5% reduction
What is an example of understanding the present?
Modelling Uk infections of COVID-19 showing fluctuations with a general decrease
What is an example of understanding the future?
Using models to predict the behaviour of COVID infections
Susceptible people –> Infected –> Resistant
Susceptible and resistant –> Escape variant –> resistant to new varient
What challenges does future modelling present?
spread available vaccines to more people in single doses?
or - complete two-dose regimes?
What are the effects of vaccinating more with a single dose?
decrease n infections circulating
reduce reproductive number of all variants (reduces S)
potentially increase probability of transmission
How does future modelling impact future policy?
Resistance after one vs two doses
Impact on the number of severe cases
What is needed to commicate models?
Trustworthiness - product of people, systems and processes within organisations that enable and support production of stats and data
Quality - stats fits their intended uses are based on appropriate data and methods, and are materially misleading
Value - statistics and data are useful, easy to access, remain relevant and support understanding of important issues
How do real-world social networks influence measures used to combat the spread of the SARS-CoV-2 virus?
Network derived from high-resolution GPS data, from citizen science-generated social network:
Seen in BBC’s ‘Contagion! The BBC Four Pandemic’
What is an overview of BBC’s contagion?
Data collected in autumn 2017 - to simulate the spread of a highly infectious flu
Hannah Fry acted as ‘Patient Zero’ by walking the streets of Haslemere in Surrey to launch an outbreak
What is the context for BBC’s contagion?
In absence of vaccine
Isolation of symptomatic individuals & quarantining of their contacts
High reproduction number in early outbreak
High transmission from pre- and asymptomatic individuals
Similar to early Covid
How did BBC’s contagion measure spread of disease?
Used public dataset on human social interactions
Contact = dyads ≥ 1 daily 5 min at ≤ 4m
Tested effects of:
test, trace, isolation and quarantine
social distancing strategy
‘test and release’
What were the main conclusion of BBC’s contagion?
No control – 75% population infected within 70days
Isolation of infected individuals - 66%
Primary contact tracing (+ quarantine) – 48%*
Secondary contact tracing (+ quarantine) – 16%*
*results in large numbers of people in quarantine
What are the effects of social distancing measures?
High social distancing reduced overall cases by 28-61%
Led to lower proportion of quarantine
What are key factors for limiting spread?
Tracing and quarantining contacts of contacts (secondary)
Combining social distancing with contact tracing
What were the limitations for BBC’s contagion?
Data from single small town
Short period of time
Not everyone involved in the town (<13 years old excluded)
Pre-covid
What is an overview of transmissibility, prevalence and patterns of movement?
Central to:
Impact of pandemic
Design of effective control strategies
What is an overview of evolutionary trees for pandemics?
Key insights into spread of SARS-CoV-2
Investigation of individual outbreaks
Transmission chains in specific settings
What is the use of phylodynamics for pandemics?
Track virus genetic changes
Identify emerging variants
Inform public health strategy
