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Infectious diseases

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1. Types of infectious disease

Infectious diseases are caused by bacteria, viruses, parasites or fungi and can be spread between people through physical contact. 

We are notified by UK Health Security Agency via your GP if you have been confirmed as suffering from one of the following infectious diseases:

  • Campylobacter
  • Salmonella
  • E.coli
  • Cryptosporidium
  • Giardia
  • Listeria
  • Shigella (Dysentery)

A member of the Food, Health and Safety team will contact you to complete a confidential questionnaire in order to investigate the source and give advice to prevent the spread of infection.


Campylobacter is the most common cause of food poisoning in the UK.

Campylobacter is the most common cause of food poisoning in the UK. You can’t see it, smell it or taste it!

The bacteria are usually found on raw or undercooked meat (particularly poultry), unpasteurised milk and untreated water.

Symptoms usually start a few days after consuming contaminated food which last between two and ten days and can be particularly severe in small children and the elderly.

Raw chicken

Do not wash raw chicken as it can increase your risk of food poisoning from Campylobacter

Splashing water from washing chicken under a tap can spread the bacteria on to hands, work surfaces, clothing and cooking equipment.

Water droplets can travel more than 50cm in every direction and only a few campylobacter cells are needed to cause food poisoning.


Salmonella bacteria live in the gut of many farm animals and you can become infected by eating raw or undercooked meat, raw eggs, milk and other dairy products.

Symptoms generally start between 12 and 72 hours after eating contaminated food and usually last around four to seven days.


Escherichia coli, also known as E.coli, are bacteria found in the digestive systems of many animals, including humans.

Most cases of E.coli food poisoning occur after eating undercooked beef (particularly mince, burgers and meatballs) or drinking unpasteurised milk.

Symptoms caused by E.coli usually start one to eight days after eating contaminated food and can last for a few days or weeks.

The Food Standards Agency has produced a factsheet to help businesses take control of the risk of food becoming contaminated by the strain E.coli 0157.


Cryptosporidium is a parasite which lives in, or on, another organism. Cryptosporidium passes out in the stools of infected humans and animals.

Infection from Cryptosporidium can be caused from contact with infected animals, for instance in farms or zoos. It is also transmitted through drinking contaminated water or swimming in lakes or rivers.

If you travel to countries where there is poor sanitation, you may be at greater risk of contracting cryptosporidium.

Symptoms generally last around 12 to 14 days but can last longer.


Giardia is a parasite which grows in the intestines of infected humans or animals. It can be transmitted by water, food or soil that has been contaminated, and by direct contact with infected humans or animals.

It is particularly widespread in countries where there is poor sanitation and limited access to clean water.

Giardia is usually treated with antibiotics. Symptoms typically last around 5 to 7 days but can last as long as several months.


Listeria is a bacteria which can be found in raw milk, pates, cooked meats, dairy products, soft cheeses and smoked seafood.

It can also be passed on through contact with the stools of infected animals or human carriers.

Symptoms are flu-like and can range from a few days to weeks.

Shigella (Dysentery)

Shigella are bacteria that can infect the digestive tract. It can be passed through direct contact with the bacteria in the stool. This can happen if an infected person doesn't wash their hands after going to the toilet and then touches food, surfaces or another person.

Shigella can also be passed in contaminated food or by drinking or swimming in contaminated water.

It usually clears up on its own within a few days but severe or persistent cases may need treating with a course of antibiotics.

In all cases of infectious disease, if symptoms persist or become worse, please seek advice from your doctor.



When this content has been updated

Last updated 26 April 2022