Epidemiology – what it is and how it’s mapping the spread of COVID-19

Crowd of people with face masks - illustration

The medical and scientific community developed ways to model the COVID-19 outbreak and spread. But what did it all involve?

The answer lies within epidemiology. Epidemiology is the study of how often diseases occur in different groups of people and why. It applies this analysis to the control of diseases and other health problems.

In the COVID-19 pandemic, it has been a vital area of research leading to swift, responsive action.

Modelling the pandemic

Take, for example, the Medical Research Council (MRC) Centre for Global Infectious Disease Analysis (GIDA).

Led by Professor Neil Ferguson, GIDA is one of the organisations at the forefront of delivering timely epidemiology analysis that informs policy responses to emerging infectious disease threats.

When the COVID-19 pandemic began, GIDA was awarded an additional £500,000 to support its real-time analysis and modelling of the pandemic and the impact of COVID-19.

Since the virus’s emergence in December 2019, GIDA has rapidly published and shared its research with other scientists, policymakers and the public.

Read the COVID-19 reports on the GIDA website.

Outbreak analytics

Epidemiology analytics played a significant role in the COVID-19 pandemic.

Researchers at the London School of Hygiene and Tropical Medicine were awarded funding from UKRI to help understand the dynamics and drivers of the COVID-19 epidemic using real-time outbreak analytics.

Led by Professor John Edmunds, this crucial study was jointly funded by MRC and the National Institute for Health Research.

An efficient response to COVID-19 required an understanding of the epidemiological and behavioural drivers of disease transmission. So, as COVID-19 evolved, analyses of epidemic drivers and policy evaluation needed constant updating to provide relevant, data-driven evidence to inform public health choices.

Professor Edmunds and his team provided rapid, continually-updated estimates of key epidemiological features such as:

  • disease severity
  • transmissibility measures.

MRC’s epidemiology studies

It’s these projects and more that highlight just how MRC’s units, institutes and centres have worked hard to create epidemiology studies that can help in the COVID-19 pandemic.

One of these units is the MRC Biostatistics Unit in Cambridge. Their researchers developed ‘Nowcasting’.

Nowcasting is the prediction of the present and is the methodology for real-time tracking of the COVID-19 pandemic. This is vital work.

Working closely with Public Health England, the researchers reconstruct the number of new COVID-19 infections over time by using:

  • a transmission model
  • data on daily COVID-19 confirmed deaths
  • information on the risk of dying
  • the time from infection to death.

This helps to estimate a measure of ongoing transmission (R), but also predicts the number of new COVID-19 deaths in different regions and age groups. It helps inform the public health response to the outbreak by providing the R0 and attack rates by region. The R0 tells you the average number of people who will contract a contagious disease from one person with that disease.

Vital COVID-19 research

The work across MRC’s units, institutes and centres to understand COVID-19 is ongoing.

MRC-funded researchers and their UKRI colleagues continue to develop new ways to model the COVID-19 outbreak and spread.

MRC Integrative Epidemiology Unit

Since the beginning of the COVID-19 outbreak, scientists at the MRC Integrative Epidemiology Unit at the University of Bristol have been engaging with research and discussion on the epidemiology, public health responses and data collection and analytical challenges.

MRC Epidemiology Unit

Staff at the MRC Epidemiology Unit at the University of Cambridge helped directly with the COVID-19 crisis by working in clinical, public health or lab testing settings.

Members of the unit’s global public health research team led efforts to crowdsource the translation of World Health Organisation facts on the coronavirus into as many African languages as possible.

The unit also undertook major COVID-19-related research. Find out more about the unit’s response to COVID-19.

MRC Lifecourse Epidemiology Unit

The MRC Lifecourse Epidemiology Unit at the University of Southampton studies the risk factors and determinants of chronic musculoskeletal disorders, diabetes mellitus and the metabolic syndrome, and cardiovascular disease, across life from conception to old age.

It also investigates potential underlying mechanisms and aims to translate these findings into novel strategies to improve human health. COVID-19 research now is a vital part of these studies.

MRC Biostatistics Unit

Using statistical modelling, analyses, and design, the MRC Biostatistics Unit at the University of Cambridge has provided estimates of key epidemic quantities for an improved understanding of COVID-19 and its effects.

The research has provided support for improved management of patients and the triaging of resources, along with evidence for the impact of clinical interventions.

Last updated: 15 October 2021

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