Health protection – collection

Seasonal influenza: guidance, data and analysis

The symptoms, diagnosis, management, surveillance and epidemiology of seasonal influenza (flu).

Influenza (flu) is a viral infection affecting the lungs and airways. The symptoms can appear very quickly and include:

  • headache
  • fever
  • cough
  • sore throat
  • aching muscles
  • joints

Complications include bacterial pneumonia, and can be life threatening especially in:

  • older people
  • those with certain underlying health conditions

It occurs most often in winter in the UK and peaks between January and March.

There are 2 types of influenza affecting people:

  • influenza A
  • influenza B

Influenza B usually causes a milder illness, and is most seen in children.

Information on the different strains of influenza virus can be found on our health protection archive website.

Annual flu programme

Vaccination of at risk groups and children can offer some protection against infection. The NHS plans each year for the demands of flu across England in its annual flu programme.

See Latest vaccine uptake guidance and the latest coverage for figures on seasonal flu vaccination rates.

Management and treatment

  1. Influenza: treatment and prophylaxis using anti-viral agents

    • Guidance
  2. Respiratory tract infections: infection control

    • Guidance
  3. H1N1 flu: critical care management for adults and children

    • Guidance
  4. Acute respiratory disease: managing outbreaks in care homes

    • Guidance
  5. Acute respiratory infections: investigating outbreaks and clusters in schools

    • Guidance

Data submission

The winter health watch summarises findings from the surveillance systems that track reported flu, norovirus, and rotavirus levels, and syndromic surveillance findings through the winter season.

  1. Acute respiratory infection outbreak: reporting form

    • Form