Listeriosis is an infection that usually develops after eating food contaminated by listeria bacteria.

In most people, listeriosis is mild and causes symptoms including a high temperature (fever), vomiting and diarrhoea. These symptoms usually pass within three days without the need for treatment.

However, in rare cases, the infection can be more severe andspread to other parts of your body, causing serious complications, such as Meningitis . Common signs ofsevere listeriosis include a stiff neck, severe headache and tremors .

Read about the treatment of diarrhoea .

If you've been vomiting or feeling sick, it should be fine to avoid eating for a short while. However, make sure you continue drinking fluids, and eat as soon as you can. Eat small, light meals and avoid fatty or spicy foods.

Contact your GP if your symptoms don't improve within a few days.

'At-risk' groups

Some peopleare particularly vulnerable tosevere listeriosis.
This includes:

  • people over 65 yearsof age
  • pregnant women and their unborn babies
  • babies less than one month old
  • people with a weakened immune system, such asthose with HIV/AIDS or receiving chemotherapy

Seeking medical help

Seek medical help if your symptoms are severe (see below).

Listeriosis is usuallydiagnosed with a blood test . If it's thought that the infection has spread to the nervous system, further tests may include an MRI scan and a lumbar puncture .

Pregnancy and children

If you're pregnant and show signs of listeriosis, or if you have a young child who shows signs of the illness, seek immediate medical advice.

If you develop listeriosis during pregnancy, you'll be given antibiotics to help prevent the infection spreading to your baby. You may also be given additional ultrasound scans to assess the health of your baby.

Treatment for listeriosis in infants is the same as for adults, although it's usually recommended that infants are kept in an intensive care unit (ICU) as a precaution.

Treating severe listeriosis in adults

If listeriosis spreads into your blood (septicaemia) or your central nervous system, you'll be admitted to hospital to receive injections of antibiotics (intravenous antibiotics) while your health is carefully monitored.

The length of time you'll need to spend in hospital depends on whether the infection has spread from your blood or nervous system to other organs, such as your brain.

Most people with severe listeriosis require at least two weeks of treatment with intravenous antibiotics. However, in the most serious cases, at least six weeks of treatment may be needed.

Preventing listeriosis

The best way to reduce your chances of developing listeriosis is to ensure you always practise good food hygiene. For example, you should:

  • not use food past its "use by" date
  • follow storage instructions on food labels
  • make sure that the temperature of your fridge is 0C to 5C
  • cook food thoroughly

If you're in a high risk group for listeriosis for example, if you're pregnant or you have a weakened immune system, avoid eating some foods, such as soft mould-ripened cheese or pt.

This is because the body's natural defences against the listeria bacteria are weaker during pregnancy.

Pregnant women are almost 20 times more likely to develop listeriosis compared with the rest of the population.

A listeria infection inpregnancy doesn't usually pose a serious threat to the mothers health. However, it can cause pregnancy and birth complications, and can result in miscarriage .

For more information, see:

  • Which foods should I avoid during pregnancy?
  • How can I avoid food poisoning during pregnancy?
Content supplied by the NHS Website

Medically Reviewed by a doctor on 4 Jan 2017