What is communicable disease surveillance?

Communicable disease surveillance is the continuous monitoring of the frequency and the distribution of disease, and death, due to infections that can be transmitted from human to human or from animals, food, water or the environment to humans, and the monitoring of risk factors for those infections.

Why do we undertake communicable disease surveillance?

Communicable disease surveillance tells us which infections are the most important causes of illness, disability and death, so that we can decide what the priorities are for control and prevention activities. It also tells us which parts of the population are most affected (e.g. children or the elderly, males or females, people living in particular areas of the country) so that we know where control and prevention efforts should be focused.

An important purpose of communicable disease surveillance is also to detect the occurrence of outbreaks or epidemics so that immediate action can be taken to identify and control the source (e.g. outbreaks of food poisoning) or so that the health service is prepared to deal with increased numbers of patients (e.g. in a flu epidemic). By monitoring how the number of cases of an infection change over time we can assess whether control and prevention activities, such as vaccination programmes, are being effective in reducing the frequency of disease and its consequences.

How do we undertake communicable disease surveillance?

Most surveillance is based on anonymised reports of infection that are submitted from doctors and laboratories to the epidemiologists at the Centre for Infection. These reports are gathered together and analysed to produce information on the frequency (number of cases) and the distribution (who is getting the infection and where they are) of disease. This is done regularly so that outbreaks and epidemics can be detected as soon as they begin, as it is necessary to take immediate action if the spread of an outbreak or epidemic is to be controlled or prevented. The results of these analyses are published in the Health Protection Report (HPR).

Important findings that require immediate action to be taken, such as outbreaks or significant increases in the number of cases in one or more parts of the country, are also communicated directly to doctors working in laboratories, public health departments, hospitals and general practice in the relevant areas, and to the Department of Health if necessary.

• Epidemiology & Surveillance
  Epidemiologists and microbiologists at the HPA are responsible for studying patterns of infectious disease in the UK population.
  Added/updated: 1 March 2010