Listeria: guidance, data and analysis

The symptoms, diagnosis, management and epidemiology of listeriosis, the infection caused by Listeria monocytogenes bacteria.

Listeria causes listeriosis, a rare but potentially life-threatening disease.

Healthy adults are likely to experience only mild infection, causing flu-like symptoms or gastroenteritis. However, listeriosis is dangerous to pregnant women, the elderly and people with weakened immune systems.

Listeria is typically spread by contaminated foods. Listeria is an unusual bacterium because it can grow at low temperatures, including refrigeration temperatures of below 5°C. It is, however, killed by cooking food thoroughly and by pasteurisation.

Information on listeriosis is available on NHS.UK.

Listeria and lambing season

Some listeriosis cases occur through contact with animals. Pregnant women are especially at risk and should avoid close contact with sheep who are giving birth, to protect themselves and their unborn child.

See the January 2014 statement about risks of lambing from Defra, DH, HSE and PHE.

The number of human pregnancies affected by contact with sheep is extremely small, but the consequences can be serious.

Diagnosis and management

Data collection

The gastrointestinal emerging and zoonotic infections (GEZI) team follow up cases of listeriosis to determine sources of outbreaks and to limit the spread of disease.


Incident investigation

Published 6 December 2013
Last updated 23 September 2020 + show all updates
  1. Added Listeria monocytogenes: incident report.

  2. Added 'Listeria contamination of frozen vegetables: professional guidance'.

  3. Added guidance for health professionals on recall of Sainsbury's 'Deli Filler' products.

  4. First published.