Gastro and diarrhoea

Gastroenteritis, or ‘gastro’, is an illness caused by infection and/or inflammation of the digestive tract.

It is characterised by nausea, vomiting, diarrhoea or stomach cramps.

Other symptoms may include fever, headache, blood or pus in the faeces, loss of appetite, bloating, lethargy and body aches.

The illness is usually self-limiting and resolves in a few days.

Causes

There are many causes of gastroenteritis including the following:

• bacteri e.g. Salmonella, Campylobacter, Shigella and Yersinia
• viruses e.g. rotavirus and norovirus
• parasites e.g. Cryptosporidium and Giardia
• bacterial toxins e.g. rom Staphylococcal bacteria.

Some antibiotics can also cause gastroenteritis in susceptible people.

It is often possible to identify the cause of gastroenteritis by testing a stool (poo sample) or less commonly, a vomit sample.

The time from contact with the bacteria or the virus and the development of symptoms is usually about 1 to 3 days.

Parasitic infections often take longer, while cases caused by a toxin usually become unwell within a few hours, depending on the type of toxin.

How it spreads

Gastroenteritis is spread by:

• eating food or drinking water that has been contaminated by vomit or faeces from an infected animal or person
• handling contaminated objects or surfaces and then touching your lips or mouth or eating hand-held food

It is caused by a toxin is acquired by eating or drinking something that has the toxin in it.

This type does not get spread person-to-person but can happen to a group of people at the same time if they all consume the same toxin-containing item.

Who is at risk

Anyone can get gastroenteritis.

Travellers to areas with inadequately treated water, especially visitors to developing countries may become ill from:

• drinking contaminated water
• eating food washed with contaminated water.

The very young and the elderly are most at risk of developing severe dehydration.

Infectious period

The infectious period is dependent upon the organism responsible.

People are more infectious when diarrhoea is present but can still be infectious after symptoms have passed.

Some people and animals can carry the germs that cause gastroenteritis in their faeces without having any symptoms.

These people and animals can still pass the illness on to others.

Treatment

The most important part of treatment is preventing and treating dehydration.

To avoid dehydration, anyone with vomiting or diarrhoea should drink extra fluids.

Rehydration therapy with oral glucose / electrolyte solution is particularly effective.

If children refuse this solution, diluted fruit juice may be given (1 part juice to 4 parts water).

Babies should continue to be offered their normal feeds plus extra fluids in between feeds.

Medicines to prevent vomiting or diarrhoea should not be given, especially to children, except when prescribed by a doctor.

When to see a doctor

Children who refuse extra fluids should see a doctor.

Additionally, anyone with the following should also see a doctor:

• prolonged (>3 days) or severe diarrhoea
• blood in their stools
• people concerned about their symptoms.

Prevention

Good hygiene practices are important in limiting the spread of gastroenteritis.

These practices include:

• washing hands thoroughly with warm soapy water, particularly:
  • after going to the toilet
  • before preparing or handling food and immediately after handling raw meat
  • after every nappy change
  • after changing soiled linen
• never changing nappies on tables or counters where food is prepared or eaten
• cleaning contaminated surfaces thoroughly using a chlorine-based steriliser in line with the manufacturer’s recommendations
• cooking meat, fish and poultry thoroughly and not letting raw meat contaminate other food
• using separate cutting boards, knives and plates for raw foods and keeping them separate from ready-to-eat-foods
• keeping cold food cold (below 5°C) and hot food hot (above 60°C) to discourage bacterial growth
• not preparing or handling food that will be eaten by others if you are vomiting or have diarrhoea.

When travelling in areas where there are concerns about the safety of the water supply, do not drink tap water.

You should also avoid uncooked or undercooked food and be sure to eat only fruit or vegetables that can be peeled.

Before travelling overseas, talk to your GP. Vaccines are available to prevent life-threatening diseases such as typhoid, cholera and hepatitis A.

Information for health professionals

To find out more, go to the NT Health website.

Contact

Contact your nearest Centre for Disease Control on the NT Health website.