Symptoms of listeriosis 

Symptoms of listeriosis in most healthy adults are mild. They usually develop from 3-70 days after the initial infection.

They are similar to flu and gastroenteritis, including:

  • a high temperature (fever) of 38ºC (100.4ºF) or above
  • muscle ache or pain
  • chills
  • feeling sick
  • being sick
  • diarrhoea

These symptoms will usually pass within a few days, even without treatment.

Severe listeriosis

If the infection spreads into the blood (septicaemia) or the central nervous system (invasive listeriosis), the symptoms of fever, muscle pain and chills tend to be much more severe.

If the infection spreads to the nervous system and the brain, additional symptoms can include:

  • severe headache
  • stiff neck
  • changes in mental state, such as confusion
  • seizures (fits)
  • lack of physical co-ordination
  • uncontrollable shaking or twitching (tremor)

If listeriosis spreads to the brain, it can cause meningitis. This is an infection of the membranes that surround the brain and spinal cord.

Listeriosis in infants

Symptoms of listeriosis in infants can include:

  • lack of interest in feeding
  • irritability
  • seizures
  • breathing difficulties, such as rapid breathing or grunting when breathing
  • skin rash
  • a higher or lower temperature than normal

The normal body temperature for a baby is around 37ºC (98.6ºF). For more information, see what is a high temperature in children?

When to seek medical help

You should seek immediate medical help if:

  • You show signs of severe listeriosis
  • Your child shows signs of listeriosis
  • You are pregnant with a fever and chills

If you need help outside normal surgery hours, you can use your local out-of-hours service.

Page last reviewed: 17/01/2013

Next review due: 17/01/2015